Astm - Composite Materials

Vista previa del material en texto

Designation: C 271 – 99
Standard Test Method for
Density of Sandwich Core Materials 1
This standard is issued under the fixed designation C 271; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the determination of the density
of sandwich construction core materials.
1.2 The values stated in SI units are to be regarded as the
standard. The inch-pound units given may be approximate.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
E 171 Specification for Standard Atmospheres for Condi-
tioning and Testing Flexible Barrier Materials2
3. Significance and Use
3.1 Density is a fundamental physical property that can be
used in conjunction with other properties to characterize the
sandwich core.
3.2 This test method provides a standard method of obtain-
ing sandwich core density data for quality control, acceptance
specification testing, and research and development.
4. Apparatus
4.1 Circulating Air Oven, capable of maintaining uniform
temperatures with an accuracy of63°C (65°F).
4.2 Desiccator, if required.
4.3 Micrometer, Gage, or Caliper, capable of measuring
accurately to 0.025 mm (0.001 in.).
4.4 Weighing Scale, capable of measuring accurately to
60.5 %.
5. Test Specimens
5.1 The test specimens may be any convenient size of core
material that can be accurately measured and as agreed upon by
the purchaser and the seller. The minimum specimen size
recommended is 300 mm (12 in.) in length and 300 mm (12 in.)
in width.
5.2 At least three specimens shall be tested.
6. Conditioning
6.1 Subject the test specimens to one of the following
conditions:
6.1.1 Standard ASTM Atmospheric Conditions (Specifica-
tion E 171) of 236 3°C (73 6 5°F) and 506 5 % relative
humidity.
6.1.2 In an oven at a temperature of 1056 3°C (2206 5°F).
6.1.3 In an oven at a temperature of 406 3°C (1206 5°F).
6.1.4 As agreed upon by the purchaser and the seller.
6.2 The conditioning time shall be either:
6.2.1 Of such duration that the specimen will have attained
constant weight (61 %), or
6.2.2 As agreed upon by the purchaser and the seller.
6.3 After conditioning, cool the specimens at room tempera-
ture. Some core materials quickly pick up moisture and must
be cooled in a desiccator.
7. Procedure
7.1 Weigh the specimens in grams (pounds) to a precision of
60.5 %.
7.2 Determine the plan dimensions of the specimens in
millimetres (inches) to a precision of60.5 %.
7.3 Measure the thickness of the specimens in millimetres
(inches) to the nearest 0.025 mm (0.001 in.).
8. Calculation
8.1 Calculate the density as follows:
d 5
1 000 000w
v (1)
where:
d 5 density, kg/m3;
w 5 final mass after conditioning, g;
v 5 final volume after conditioning, mm3;
or
D 5
1728W
V (2)
where:
D 5 density, lb/ft3;
W 5 final mass after conditioning, lb; and
V 5 final volume after conditioning, in.3.
8.2 Conversion of density values to either SI or inch-pound
units is accomplished by using the following equations:
1 This test method is under the jurisdiction of ASTM Committee D-30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved Oct. 10, 1999. Published January 2000. Originally
published as C 271 – 51 T. Last previous edition C 271 – 94(1999).
2 Annual Book of ASTM Standards, Vol 15.09.
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 5 0.0624d (3)
d 5 16D
9. Report
9.1 The report shall include the following:
9.1.1 Complete description of core material,
9.1.2 Size of test specimens,
9.1.3 Conditioning procedures, and
9.1.4 Core density, individual values and average.
10. Precision and Bias
10.1 Precision—It is not possible to specify the precision of
the procedure in Test Method C 271 for measuring the sand-
wich core material density because of the unavailability of
consistent samples for testing.
10.2 Bias—Since there is no accepted reference material
suitable for determining the bias for the procedure in this test
method, bias has not been determined.
11. Keywords
11.1 density; sandwich core
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at
610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org).
C 271
2
Designation: C 272 – 01
Standard Test Method for
Water Absorption of Core Materials for Structural Sandwich
Constructions 1
This standard is issued under the fixed designation C 272; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the determination of the relative
amount of water absorption by various types of structural core
materials when immersed or in a high relative humidity
environment. This test method is intended to apply to only
structural core materials; honeycomb, foam, and balsa wood.
1.2 The values stated in SI units are to be regarded as the
standard. The inch-pound units given may be approximate.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
C 271 Test Method for Density of Sandwich Core Materi-
als2
C 274 Terminology of Structural Sandwich Constructions2
D 1193 Specification for Reagent Water3
3. Terminology
3.1 Definitions—Terminology C 274 defines terms relating
to sandwich constructions.
4. Summary of Test Method
4.1 A small piece of the core material is conditioned in
various moisture conditions, and the amount of moisture
absorbed is measured by the weight increase in the specimen.
5. Significance and Use
5.1 The moisture content of most core materials is related to
such properties as electrical properties (such as dielectric
constant, loss tangent, and electrical resistance) and mechani-
cal properties (such as strength and modulus). The amount of
weight the structure may gain by the core absorbingwater is
also important. It should be noted that in a sandwich panel
there are facings bonded on two sides of the core that affect the
amount of water absorbed by the core.
6. Interferences
6.1 Material and Specimen Preparation—Cracks in the
specimen and rough surfaces can increase the apparent water
absorption.
6.2 Surface Water—Some core materials tend to collect
water on the surfaces or trap water in corners, and, if not
removed will give incorrect results.
7. Apparatus
7.1 Analytical Balance, capable of measurement to 0.001 g.
7.2 Circulating Air Oven, capable of maintaining uniform
temperatures with an accuracy of63°C (65°F).
7.3 Humidity Chamber, capable of maintaining uniform
relative humidity with an accuracy of65 % and a uniform
temperature with an accuracy of63°C (65°F).
7.4 The water used in this test method shall be distilled
water (Specification D 1193, Type IV reagent water) or deion-
ized water.
8. Sampling and Test Specimens
8.1 Test at least five specimens per test condition unless
valid results can be gained through the use of fewer specimens,
such as in the case of a designed experiment.
8.2 The test specimen shall be 75 by 75 by 12.7 mm (3 by
3 by 0.5 in.) thick. The thickness of the specimen shall be in the
same direction as the core thickness when used in a sandwich
panel.
8.3 Machine, saw, or shear the test specimens from the core
sample so as to have smooth surfaces that are free from cracks.
8.4 Measure the length and width dimensions to the nearest
0.25 mm (0.01 in.) and the thickness to the nearest 0.025 mm
(0.001 in.).
9. Calibration
9.1 The accuracy of all measuring equipment shall have
certified calibrations that are current at the time of use of the
equipment.
1 This test method is under the jurisdiction of ASTM Committee D30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved Sept. 10, 2001. Published November 2001. Originally
published as C 272 – 51 T. Last previous edition C 272 – 91 (1996).
2 Annual Book of ASTM Standards, Vol 15.03.
3 Annual Book of ASTM Standards, Vol 11.01.
1
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
10. Conditioning
10.1 Weigh the specimens individually and then oven dry as
follows:
10.1.1 For materials whose water absorption value would be
affected by temperatures up to approximately 110°C (230°F),
dry the specimens in an oven for 24 h at 50°6 3°C (1206
5°F), cool in a desiccator to room temperature, remove, and
immediately weigh and record the weight.
10.1.2 For materials whose water absorption value has been
shown not to be affected by temperatures up to 110°C (230°F),
dry the specimens in an oven for 2 h at 1056 3°C (2256 5°F),
cool in a desiccator to room temperature, remove, and imme-
diately weigh and record the weight.
10.1.3 In the case of a new material of which the water
absorption properties are not known, condition the specimens
in accordance with 10.1.1 and 10.1.2 until sufficient experience
on the effect of temperature is achieved to indicate the selection
of the most satisfactory method.
11. Procedure
11.1 Test Method A—Twenty-Four-Hour Immersion—
Completely immerse the specimens in a container of 236 3°C
(73 6 5°F) water. Materials that float should be held under
water by a loose net. At the end of 24 h, remove the specimens,
shake vigorously, wipe off all surface water with a dry cloth,
and immediately weigh and record the weight. For materials
that tend to collect water on the surfaces or trap water in
corners, dip the specimen in alcohol, shake vigorously, allow
the alcohol to evaporate, and immediately weigh and record the
weight.
11.2 Test Method B—Elevated Temperature Humidity:
11.2.1 The standard condition shall be 706 3°C (1606
5°F) and 856 5 % relative humidity for 30 days. However,
other temperatures, relative humidities, and lengths of time can
be used but must be reported.
11.2.2 Place the specimens in the chamber with the 75 by 75
mm (3 by 3 in.) planes in the vertical position and the ends
sitting on an open base (such as a screen or perforated
material).
11.2.3 The standard conditioned specimens should not have
condensed water on their surfaces. Therefore, take the speci-
mens out of the chamber, allow to cool to room temperature,
and immediately weigh and record the weight.
11.2.4 For specimens in conditions that cause condensation
water to be on the specimen’s surfaces, remove the specimens
from the chamber, shake vigorously, wipe off all surface water
with a dry cloth (if required), dip the specimen in alcohol,
shake vigorously, allow the alcohol to evaporate, and immedi-
ately weigh and record the weight.
11.3 Test Method C—Maximum Percent Weight Gain—
Completely immerse the specimens in a container of water at
a temperature of 236 3°C (73 6 5°F). Materials that float
should be held under water by a loose net. At the end of 48 h,
remove the specimens one at a time, shake vigorously, wipe off
all surface water with a dry cloth (if required), dip the
specimens in alcohol, shake vigorously, allow the alcohol to
evaporate, and immediately weigh, and record the weight.
Place the specimens back into the water and repeat this process
until the weight gain after one 48-h interval is less than 2 % of
the entire weight gain of all the previous intervals.
11.4 Surface Water Correction—When surface water on the
specimens presents a problem, determine the amount of surface
water left on the specimens using the following procedure.
Weigh five control samples, dip quickly in water, then follow
the same procedure used on the actual specimens to determine
the weight gain. Subtract the average surface water weight gain
to correct the actual wet specimen weight.
12. Calculation
12.1 Calculate the percentage increase in weight as follows:
Increase in weight, %5
W2 D
D 3 100 (1)
where:
W = wet weight, and
D = dry weight.
12.2 Calculate the specimen density in accordance with Test
Method C 271.
13. Report
13.1 Report the following information:
13.2 Description of core material tested,
13.3 Product designation and batch number,
13.4 Method and conditions of test environment used,
13.5 Individual specimen dimensions, weight, and density
before conditioning,
13.6 Individual specimen weight increase percentage (note
if corrected for surface water), and
13.7 Average, standard deviation, and coefficient of varia-
tion of the weight increase percentage.
14. Precision and Bias
14.1 Precision—The data required for the development of a
precision statement is not available for this test method.
14.2 Bias—Bias cannot be determined for this test method
as no accepted reference standard exists.
15. Keywords
15.1 moisture content; water absorption; water saturation
C 272
2
The ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item
mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights,
and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the
responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should
make your views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
United States. Individual reprints (single or multiple copies) of this standard may be obtained by contactingASTM at the above
address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website
(www.astm.org).
C 272
3
Designation: C 272 – 01
Standard Test Method for
Water Absorption of Core Materials for Structural Sandwich
Constructions 1
This standard is issued under the fixed designation C 272; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method covers the determination of the relative rate amount of water absorption by various types of structural core
materials when immersed or in a high relative humidity environment. This test method is intended to apply to only structural core
materials; honeycomb, foam, and balsa wood.
1.2 The values stated in inch-pound SI units are to be regarded as the standard. The SI inch-pound units given may be
approximate.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
C 271 Test Method for Density of Sandwich Core Materials2
C 274 Terminology of Structural Sandwich Constructions2
D 1193 Specification for Reagent Water3
3. Significance and Use
3.1 The moisture content of most core materials is relatedTerminology
3.1 Definitions—Terminology C 274 defines terms relating to such properties as electrical properties (such as dielectric, loss
tangent, electrical resistance) and mechanical properties (such as strength and modulus). Also important is the amount of weight
the structure may gain by the core absorbing water. It should be noted that in a sandwich panel there are facings bonded on two
sides of the core that effect the amount of water absorbed by the core. constructions.
4. Summary of Test Method
4.1 A small piece of the core material is conditioned in various moisture conditions, and the amount of moisture absorbed is
measured by the weight increase in the specimen.
5. Significance and Use
5.1 The moisture content of most core materials is related to such properties as electrical properties (such as dielectric constant,
loss tangent, and electrical resistance) and mechanical properties (such as strength and modulus). The amount of weight the
structure may gain by the core absorbing water is also important. It should be noted that in a sandwich panel there are facings
bonded on two sides of the core that affect the amount of water absorbed by the core.
6. Interferences
6.1 Material and Specimen Preparation—Cracks in the specimen and rough surfaces can increase the apparent water
absorption.
1 This test method is under the jurisdiction of ASTM Committee D-30 on Composite Materials and is the direct responsibility of Subcommittee D30.09 on Sandwich
Construction.
Current edition approved Dec. 15, 1991. Sept. 10, 2001. Published May 1992. November 2001. Originally published as C 272 – 51 T. Last previous edition C272 – 53
(1980).e1 C 272 – 91 (1996).
2 Annual Book of ASTM Standards, Vol 15.03.
3 Annual Book of ASTM Standards, Vol 11.01.
C 272 – 91 (1996)
2
6.2 Surface Water—Some core materials tend to collect water on the surfaces or trap water in corners, and, if not removed will
give incorrect results.
7. Apparatus
47.1 Analytical Balance, capable of measurement to 0.001 g.
47.2 Circulating Air Oven, capable of maintaining uniform temperatures with an accuracy of65°F (63°C).
4.3 63°C (65°F).
7.3 Humidity Chamber, capable of maintaining uniform relative humidity with an accuracy of65 % and a uniform temperature
with an accuracy of65°F (63°C).
4.4 The63°C (65°F).
7.4 The water used in this test method should shall be distilled water (Specification D 1193, Type IV reagent water) or deionized
water.
58. Sampling and Test Specimens
58.1 Thest at least five specimens per test condition unless valid results can be gained through the use of fewer specimens, such
as in the case of a designed experiment.
8.2 The test specimen shall be 3 75 by 3 75 by 0.5 in. thick (76.2 by 76.2 by 12.7 mm (3 by 3 by 0.5 in.) thick). The thickness
of the specimen shall be in the same direction as the core thickness when used in a sandwich panel.
58.23 Machine, saw, or shear the test specimens from the core sample so as to have smooth surfaces that are free from cracks.
58.34 Measure the length and width dimensions to the nearest 0.01 in. (0.254 mm) 0.25 mm (0.01 in.) and the thickness to the
nearest 0.001 in. (0.0254 mm).
6. 0.025 mm (0.001 in.).
9. Calibration
9.1 The accuracy of all measuring equipment shall have certified calibrations that are current at the time of use of the equipment.
10. Conditioning
6.1 Weigh five
10.1 Weigh the specimens individually and then oven dry as follows:
610.1.1 For materials whose water absorption value would be affected by temperatures up to approximately 230°F (110°C),
110°C (230°F), dry the specimens in an oven for 24 h at 120 50°6 5°F (49° 3°C (1206 3°C), 5°F), cool in a desiccator to room
temperature, remove, and immediately weigh and record the weight.
610.1.2 For materials whose water absorption value has been shown not to be affected by temperatures up to 230°F (110°C),
110°C (230°F), dry the specimens in an oven for 2 h at 225 1056 5°F (107 3°C (2256 3°C), 5°F), cool in a desiccator to room
temperature, remove, and immediately weigh and record the weight.
610.1.3 In the case of a new material of which the water absorption properties of which are not known, condition the specimens
in accordance with 6 10.1.1 and 6 10.1.2 until sufficient experience on the effect of temperature is achieved to indicate the selection
of the most satisfactory method.
711. Procedure
711.1 Test Method A—Twenty-Four-Hour Immersion—Completely immerse the specimens in a container of 73 236 5°F (23
3°C (73 6 3°C) 5°F) water. Materials that float should be held under water by a loose net. At the end of 24 h, remove the
specimens, shake vigorously, wipe off all surface water with a dry cloth, and immediately weigh and record the weight. For
materials that tend to collect water on the surfaces or trap water in corners, dip the specimen in alcohol, shake vigorously, allow
the alcohol to evaporate, and immediately weigh and record the weight.
711.2 Test Method B—Elevated Temperature Humidity:
711.2.1 The standard condition shall be 160 706 5°F (71 3°C (1606 3°C) 5°F) and 856 5 % relative humidity for 30 days.
However, other temperatures, relative humidities, and lengths of time can be used but must be reported.
711.2.2 Place the specimens in the chamber with the 3 75 by 3 in. (76.2 75 mm (3 by 76.2 mm) 3 in.) planes in the vertical
position and the ends sitting on an open base (such as a screen or perforated material).
711.2.3 The standard conditioned specimens should not have condensed water on their surfaces. Therefore, take the specimens
out of the chamber, allow to cool to room temperature, and immediately weigh and record the weight.
711.2.4 For specimens in conditions that cause condensation water to be on the specimen’s surfaces, remove the specimens from
the chamber, shake vigorously, wipe off all surface water with a dry cloth, (if required), dip the specimen in alcohol, shake
vigorously, allow the alcohol to evaporate, and immediately weigh and record the weight.
711.3 Test Method C—Maximum Percent Weight Gain—Completely immerse the specimens in a container of water at a
temperature of 73 236 3°C (736 5°F). Materials that float should be held under water by a loose net. At the end of 48 h, remove
the specimens one at a time, shake vigorously,wipe off all surface water with a dry cloth (if required), dip the specimens in alcohol,
C 272 – 01
3
shake vigorously, allow the alcohol to evaporate, and immediately weigh, and record the weight. Place the specimens back into
the water and repeat this process until the weight gain after one 48-h interval is less than 2 % of the entire weight gain of all the
previous intervals.
711.4 Surface Water Correction—When surface water on the specimens presents a problem, determine the amount of surface
water left on the specimens using the following procedure. Weigh five control samples, dip quickly in water, then follow the same
procedure used on the actual specimens to determine the weight gain. Subtract the average surface water weight gain to correct
the actual wet specimen weight.
812. Calculation
812.1 Calculate the percentage increase in weight as follows:
Increase in weight, %5
W2 D
D 3 100 (1)
where:
W = wet weight, and
D = dry weight.
812.2 Calculate the specimen density in accordance with Test Method C 271.
913. Report
913.1 Report the following information:
9.13.12 Description of core material tested,
9.13.23 Product designation and batch number,
9.1.3.4 Method and conditions of test environment used,
9.13.45 Individual specimen dimensions, weight, and density before conditioning,
9.13.56 Individual specimen weight increase percentage, (note if corrected for surface water), and
9.1.6 The average,
13.7 Average, standard deviation, and coefficient of variation of the weight increase percentage.
104. Precision and Bias
10.1 Since there is no accepted reference material suitable
14.1 Precision—The data required for determining the development of a precision and bias, no statement is not available for
this test method.
14.2 Bias—Bias cangnot be determined for this test method as no accepted reference standard exists.
115. Keywords
115.1 moisture content; water absorption; water saturation
C 272 – 01
4
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned
in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk
of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the
responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should
make your views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above
address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website
(www.astm.org).
C 272 – 01
5
Designation: C 272 – 91 (Reapproved 1996)
Standard Test Method for
Water Absorption of Core Materials for Structural Sandwich
Constructions 1
This standard is issued under the fixed designation C 272; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the determination of the relative
rate of water absorption by various types of structural core
materials when immersed or in a high relative humidity
environment. This test method is intended to apply to only
structural core materials; honeycomb, foam, and balsa wood.
1.2 The values stated in inch-pound units are to be regarded
as the standard. The SI units given may be approximate.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
C 271 Test Method for Density of Sandwich Core Materi-
als2
D 1193 Specification for Reagent Water3
3. Significance and Use
3.1 The moisture content of most core materials is related to
such properties as electrical properties (such as dielectric, loss
tangent, electrical resistance) and mechanical properties (such
as strength and modulus). Also important is the amount of
weight the structure may gain by the core absorbing water. It
should be noted that in a sandwich panel there are facings
bonded on two sides of the core that effect the amount of water
absorbed by the core.
4. Apparatus
4.1 Analytical Balance, capable of measurement to 0.001 g.
4.2 Circulating Air Oven, capable of maintaining uniform
temperatures with an accuracy of65°F (63°C).
4.3 Humidity Chamber, capable of maintaining uniform
relative humidity with an accuracy of65 % and a uniform
temperature with an accuracy of65°F (63°C).
4.4 The water used in this test method should be distilled
water (Specification D 1193, Type IV reagent water) or deion-
ized water.
5. Test Specimens
5.1 The test specimen shall be 3 by 3 by 0.5 in. thick (76.2
by 76.2 by 12.7 mm thick). The thickness of the specimen shall
be in the same direction as the core thickness when used in a
sandwich panel.
5.2 Machine, saw, or shear the test specimens from the core
sample so as to have smooth surfaces that are free from cracks.
5.3 Measure the length and width dimensions to the nearest
0.01 in. (0.254 mm) and the thickness to the nearest 0.001 in.
(0.0254 mm).
6. Conditioning
6.1 Weigh five specimens individually and then oven dry as
follows:
6.1.1 For materials whose water absorption value would be
affected by temperatures approximately 230°F (110°C), dry the
specimens in an oven for 24 h at 1206 5°F (49°6 3°C), cool
in a desiccator to room temperature, remove, immediately
weigh and record the weight.
6.1.2 For materials whose water absorption value has been
shown not to be affected by temperatures up to 230°F (110°C),
dry the specimens in an oven for 2 h at 2256 5°F (1076 3°C),
cool in a desiccator to room temperature, remove, and imme-
diately weigh and record the weight.
6.1.3 In the case of a new material the water absorption
properties of which are not known, condition the specimens in
accordance with 6.1.1 and 6.1.2 until sufficient experience on
the effect of temperature is achieved to indicate the selection of
the most satisfactory method.
7. Procedure
7.1 Test Method A—Twenty-Four-Hour Immersion—
Completely immerse the specimens in a container of 736 5°F
(23 6 3°C) water. Materials that float should be held under
water by a loose net. At the end of 24 h, remove the specimens,
shake vigorously, wipe off all surface water with a dry cloth,
immediately weigh and record the weight. For materials that
tend to collect water on the surfaces or trap water in corners,
1 This test method is under the jurisdiction of ASTM Committee D-30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved Dec. 15, 1991. Published May 1992. Originally
published as C 272 – 51 T. Last previous edition C 272 – 53 (1980).e1
2 Annual Book of ASTM Standards, Vol 15.03.
3 Annual Book of ASTM Standards, Vol 11.01.
1
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
NOTICE: This standardhas either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
dip the specimen in alcohol, shake vigorously, allow the
alcohol to evaporate and immediately weigh and record the
weight.
7.2 Test Method B—Elevated Temperature Humidity:
7.2.1 The standard condition shall be 1606 5°F (716 3°C)
and 856 5 % relative humidity for 30 days. However, other
temperatures, relative humidities, and lengths of time can be
used but must be reported.
7.2.2 Place the specimens in the chamber with the 3 by 3 in.
(76.2 by 76.2 mm) planes in the vertical position and the ends
sitting on an open base (such as a screen or perforated
material).
7.2.3 The standard conditioned specimens should not have
condensed water on their surfaces. Therefore, take the speci-
mens out of the chamber, allow to cool to room temperature,
and immediately weigh and record the weight.
7.2.4 For specimen in conditions that cause condensation
water to be on the specimen’s surfaces, remove the specimens
from the chamber, shake vigorously, wipe off all surface water
with a dry cloth, (if required) dip the specimen in alcohol,
shake vigorously, allow the alcohol to evaporate, and immedi-
ately weigh and record the weight.
7.3 Test Method C—Maximum Percent Weight Gain—
Completely immerse the specimens in a container of water at
a temperature of 736 5°F. Materials that float should be held
under water by a loose net. At the end of 48 h, remove the
specimens one at a time, shake vigorously, wipe off all surface
water with a dry cloth and immediately weigh, and record the
weight. Place the specimens back into the water and repeat this
process until the weight gain after one 48-h interval is less than
2 % of the entire weight gain of all the previous intervals.
7.4 Surface Water Correction—When surface water on the
specimens presents a problem determine the amount of surface
water left on the specimens using the following procedure.
Weigh five control samples, dip quickly in water, then follow
the same procedure used on the actual specimens to determine
the weight gain. Subtract the average surface water weight gain
to correct the actual wet specimen weight.
8. Calculation
8.1 Calculate the percentage increase in weight as follows:
Increase in weight, %5
W2 D
D 3 100 (1)
where:
W 5 wet weight and
D 5 dry weight.
8.2 Calculate the specimen density in accordance with Test
Method C 271.
9. Report
9.1 Report the following information:
9.1.1 Description of core material tested,
9.1.2 Product designation and batch number,
9.1.3 Method and conditions of test environment used,
9.1.4 Individual specimen dimensions, weight and density
before conditioning,
9.1.5 Individual specimen weight increase percentage, note
if corrected for surface water, and
9.1.6 The average, standard deviation, and coefficient of
variation of the weight increase percentage.
10. Precision and Bias
10.1 Since there is no accepted reference material suitable
for determining precision and bias, no statement is being made.
11. Keywords
11.1 moisture content; water absorption; water saturation
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, 100 Barr Harbor Drive, West Conshohocken, PA 19428.
C 272
2
Designation: C 273 – 00 e1
Standard Test Method for
Shear Properties of Sandwich Core Materials 1
This standard is issued under the fixed designation C 273; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
e1 NOTE—In 5.3, the value 6 000 000 lb-in.2/in. was editorially corrected to 600 000 lb-in.2/in. in July 2000.
1. Scope
1.1 This test method covers the determination of shear
properties of sandwich construction core materials associated
with shear distortion of planes parallel to the facings. It covers
the determination of shear strength parallel to the plane of the
sandwich, and the shear modulus associated with strains in a
plane normal to the facings. The test may be conducted on core
materials bonded directly to the loading plates or the sandwich
facings bonded to the plates.
1.2 The values stated in SI units are to be regarded as the
standard. The inch-pound units given may be approximate.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
C 393 Test Method for Flexural Properties of Flat Sandwich
Constructions2
C 394 Test Method for Shear Fatigue of Sandwich Core
Materials2
E 4 Practices for Force Verification of Testing Machines3
3. Significance and Use
3.1 The core shear properties are fundamental properties
that are used in the design of sandwich panels. This test method
provides information on the load-deflection behavior of sand-
wich constructions or cores when loaded in shear parallel to the
plane of the facings. From a complete load-deflection curve, it
is possible to compute core shear stress at any load (such as the
shear stress at proportional limit, at yield, or at maximum load)
and to compute an effective core shear modulus.
3.2 The test does not produce pure shear, but the specimen
length is prescribed so that secondary stresses have a minimum
effect. Approximate shear properties can also be obtained from
a sandwich flexure test (see Test Method C 393).
3.3 This test method provides a standard method of obtain-
ing sandwich core shear data for quality control, acceptance
specification testing, sandwich design, and research and devel-
opment.
4. Apparatus
4.1 Test Machine, capable of maintaining a controlled load-
ing rate and indicating the load with an accuracy of61 % of
the indicated value. The accuracy of the test machine shall be
verified in accordance with Practices E 4.
4.2 Deflectometer, compressometer, or extensometer, ca-
pable of measuring the displacement with a precision of at least
61 %.
4.3 Micrometer, gage, or caliper, capable of measuring
accurately to 0.025 mm (0.001 in.).
5. Test Specimens
5.1 The test specimen shall have a thickness equal to the
thickness of the sandwich, a width not less than 50 mm (2 in.),
and a length not less than twelve times the thickness, except as
agreed upon by the purchaser and the seller.
5.2 Measure the thickness to the nearest 0.025 mm (0.001
in.) and the length and width to the nearest 0.25 mm (0.01 in.).
Weigh the specimen to the nearest 0.1 g and calculate the
specimen density.
5.3 The test specimen shall be rigidly supported by means
of steel plates bonded to the facings (Note 1) as shown in Fig.
1. The thickness of the plates may be varied in accordance with
the strength of the sandwich, but the platelength shall be such
that the line of action of the direct tensile or compressive force
shall pass through the diagonally opposite corners of the
sandwich as shown in Fig. 1. A correct line of load action may
also be obtained by modifying the core length to thickness ratio
provided the requirements in 5.1 are fulfulled. It has been
1 This test method is under the jurisdiction of ASTM Committee D30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved Jan. 10, 2000. Published March 2000. Originally
published as C 273 – 51T. Last previous edition C 273 – 94.
2 Annual Book of ASTM Standards, Vol 15.03.
3 Annual Book of ASTM Standards, Vol 03.01.
1
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
found that loading plates having a bending stiffness per unit
width, D = EI/b, not less than 2.67 MN - mm2/mm width per
millimetre of core thickness (600 000 lb-in.2/in. per inch of
core thickness) have performed satisfactorily.
5.4 If the core material shows directional characteristics
with respect to shear strength, separate tests shall be made to
obtain shear stresses in each of the principal directions.
NOTE 1—To ensure a core shear failure on some honeycomb cores, two
plies of adhesive must be used to bond the honeycomb to the steel plates.
This provides deeper adhesive fillets on the honeycomb cell walls.
6. Conditioning
6.1 When the physical properties of the component materi-
als are affected by moisture, bring the test specimens to
constant weight (61 %) before testing, preferably in a condi-
tioning room with temperature and humidity control, and make
the shear tests, preferably, in a room under the same conditions.
A temperature of 236 3°C (736 5°F) and a relative humidity
of 50 6 5 % are recommended.
7. Procedure
7.1 Apply the load to the ends of the rigid plates in
compression or tension through a spherical bearing block or a
universal joint so as to distribute the load uniformly across the
width of the specimen (Fig. 2 and Fig. 3). The tensile shear
plates can be attached with bolts or pins to the loading fixture.
Apply the load at a constant rate of movement of the testing
machine cross-head at such a rate that the maximum load will
occur within 3 to 6 min (Note 2).
NOTE 2—A suggested rate of cross-head movement is 0.50 mm/min
(0.020 in./min).
7.2 The failure mode desired is a 100 % shear failure of the
core. Specimens that exhibit cohesive failures of the core-to-
plate adhesive or adhesion failures to the core or plates should
be rejected. The thickness of the adhesive bond to honeycomb
core (adhesive-filled depth into the honeycomb core cells) may
affect the core shear strength and modulus values depending on
the core thickness.
7.3 Data for load-deflection curves may be used to deter-
mine the effective shear modulus of the core material. Measure
the relative displacement between the steel plates by means of
transducers, compressometers or extensometers. The displace-
ment apparatus can be on the specimen side or on the back, and
it shall be as close to the center as possible.
8. Calculation
8.1 Calculate the shear stress as follows:
t 5
P
L b (1)
where:
t = core shear stress, MPa (psi);
P = load on specimen, N (lb);
L = length of specimen, mm (in.); and
b = width of specimen, mm (in.).
8.2 Obtain the ultimate shear strength using Eq 1 whenP
equals the maximum load and the shear yield strength whereP
equals the yield load. For core materials that yield more than
2 % strain, use the 2 % offset method for the yield strength.
8.3 Calculate the shear modulus as follows:
G 5
S t
L b (2)
where:
G = core shear modulus, MPa (psi);
S = DP/Du, slope of initial portion of load-deflection
curve, N/mm (lb/in.);
u = displacement of loading plates; and
t = thickness of core, mm (in.).
9. Report
9.1 The report shall include the following:
9.1.1 Mode of testing; tension or compression,
9.1.2 Description of test specimens; core material, facings if
used,
9.1.3 Dimensions of the test specimens, core orientation,
9.1.4 Method of bonding specimen to plates; adhesive, cure
cycle, and pressure,
9.1.5 Specimens conditioning, if any,
9.1.6 Test temperature and specimens time at temperature,
9.1.7 Test machine cross-head loading rate,
9.1.8 Shear strength; individual values and average,
9.1.9 Shear modulus; individual values and average,
9.1.10 Load-deflection curves, if required, and
9.1.11 Description of failure mode; whether core, adhesive,
or bond failure occurred.
FIG. 1 Plate Shear Specimens, Load Line of Action
C 273 – 00e1
2
10. Precision and Bias
10.1 Precision—The precision of the procedure in Test
Method C 273 for measuring sandwich core material shear
properties is not available.
10.2 Bias—Since there is no accepted reference material
suitable for determining the bias for the procedures in this test
method, bias has not been determined.
11. Keywords
11.1 sandwich core; shear; shear modulus; shear strength
(a) Bolted Specimen (b) Pinned Specimen
FIG. 2 Tensile Plate Shear Tests
C 273 – 00e1
3
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned
in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk
of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the
responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should
make your views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above
address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website
(www.astm.org).
FIG. 3 Compressive Plate Shear Test
C 273 – 00e1
4
Designation: C 274 – 99
Standard Terminology of
Structural Sandwich Constructions 1
This standard is issued under the fixed designation C 274; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This terminology covers terms necessary for a basic
uniform understanding and usage of the language peculiar to
structural sandwich constructions. The simplest structural
sandwich is a three layered construction formed by bonding a
thin layer (facing) to each side of a thick layer (core).
2. Referenced Documents
2.1 ASTM Standards:
D 907 Terminology of Adhesives2
3. Terminology
adhesive, n—a substance capable of holding materials together
by surface attachment.
DISCUSSION—This definition was established in Terminology D 907.
bending stiffness, n—the sandwich property which resists
bending deflections. D5EI; the facing modulus times the
panel moment of inertia.
co-curing, n—curing a composite laminate and simultaneously
bonding it to the sandwich core.
co-fab, n—fabrication process where close-outs and inserts are
bonded into the panel the same time the facings are bonded
to the core.
core, n—a centrally located layer of a sandwich construction,
usually low density, which separates and stabilizes thefacings and transmits shear between the facings and provides
most of the shear rigidity of the construction.
doublers, n—an extra piece of facing attached to strength or
stiffen the panel or to distribute the load more widely to the
core.
edge close-outs, n—members placed around the panel sides to
protect the sandwich from damage or to attach the panel to
a support or another panel.
facing delamination, n—where the facing becomes disbonded
from the core.
face dimpling, n—buckling of the compressive facing into the
individual cells of the honeycomb core due to compressive
loading or the prepreg facing sagging into the individual
honeycomb cells during cocure.
face wrinkling, n—buckling of the compressive facing into or
away from the core. This progresses the width of the panel
and causes failure.
facing, n—the outermost layer or composite component of a
sandwich construction, generally thin and of high density,
which resists most of the edgewise loads and flatwise
bending moments: synonymous with face, skin and
facesheet.
inplane loads, n—loads which are parallel to the facings.
inserts, n—apparatus placed into the sandwich for attaching
items: synonymous with hard points.
post-fab, n—fabrication process where close-outs and inserts
are attached or put into the panel after the facings are bonded
to the core.
shear crimping, n—buckling of the compressive facing due to
low core shear modulus. Usually causes the core to fail in
shear at the crimp.
shear rigidity, n—the sandwich property which resists shear
distortions: synonymous with shear stiffness. U5hG; the
core thickness (approximate) times the core shear modulus.
structural sandwich construction, n—a laminar construction
comprising a combination or alternating dissimilar simple or
composite materials assembled and intimately fixed in rela-
tion to each other so as to use the properties of each to attain
specific structural advantages for the whole assembly.
transverse loads, n—loads which are perpendicular to the
facings: synonymous with flatwise load.
4. Keywords
4.1 core; facing; loads; rigidity; sandwich; sandwich con-
struction; stiffness
1 This test method is under the jurisdiction of ASTM Committee D-30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved Oct. 10, 1999. Published February 2000. Originally
published as C 274 – 51 T. Last previous edition C 274 –94.
2 Annual Book of ASTM Standards, Vol 15.06.
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at
610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org).
C 274
2
Designation: C 297 – 94 (Reapproved 1999)
Standard Test Method for
Flatwise Tensile Strength of Sandwich Constructions 1
This standard is issued under the fixed designation C 297; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method covers the determination of the core
flatwise tension strength or the bond between core and facings
of an assembled sandwich panel. The test consists of subjecting
a sandwich construction to a tensile load normal to the plane of
the sandwich, such load being transmitted to the sandwich
through thick loading blocks bonded to the sandwich facings or
directly to the core.
1.2 The values stated in SI units are to be regarded as the
standard. The inch-pound units given may be approximate.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
E 4 Practices for Force Verification of Testing Machines2
3. Significance and Use
3.1 For a sandwich panel to function properly, the facings
must have a sufficient bond to the core.
3.2 This test method provides information on how well the
facings are bonded to the core or the flatwise tensile strength of
the core. It is mainly used as a quality control test for bonded
sandwich panels.
4. Apparatus
4.1 Test machine, capable of maintaining a controlled load-
ing rate and indicating the load with an accuracy of61 % of
the indicated value. The accuracy of the test machine shall be
verified in accordance with Practices E 4.
4.2 Loading fixtures, the loading fixtures shall be self-
aligning and shall not apply eccentric loads. A satisfactory type
of apparatus is shown in Fig. 1. The loading blocks shall be
sufficiently stiff to keep the bonded facings essentially flat
under load. Loading blocks 40 to 50 mm (1.5 to 2.0 in.) thick
have been found to perform satisfactorily.
4.3 Micrometer, gage, or caliper, capable of measuring
accurately to 0.025 mm (0.001 in.).
5. Test Specimens
5.1 Test specimens shall be square or round and equal in
thickness to the sandwich panel thickness. All dimensions shall
be measured to the nearest 0.25 mm (0.01 in.). Minimum areas
for various types of core materials are given below:
5.1.1 For continuous cores, such as balsa wood and foams,
the minimum facing area of the specimen shall be 625 mm2 (1
in.2).
5.1.2 For open-celled cores, such as honeycomb, having
cells less than 6 mm (0.5 in.), the minimum area shall be 2600
mm2(4 in.2), and for cells 6 mm (0.5 in.) or greater, the
minimum area shall be 5800 mm2 (9 in.2).
5.2 The loading blocks shall be bonded to the facings of the
test specimen using a suitable adhesive. Ideally, the bonding
temperature and pressure shall not appreciably affect the
existing bond between facing and core. The bonding pressure
shall not be greater than the original facing to core bonding
pressure. If possible, the assembly temperature shall be room
temperature or at least 28°C (50°F) lower than that at which the
sandwich was originally bonded.
5.3 The number of test specimens and the method of their
selection depend on the purpose of the particular test under
consideration, and no general rule can be given to cover all
cases. However, when specimens are to be used for acceptance
tests, at least five specimens shall be tested.
6. Conditioning
6.1 When the physical properties of the component materi-
als are affected by moisture, bring the test specimens to
constant weight (61 %) before testing, preferably in a condi-
tioning room with temperature and humidity control,and make
the tests, preferably, in a room under the same conditions. A
temperature of 236 3°C (736 5°F) and a relative humidity of
50 6 5 % are recommended.
1 This test method is under the jurisdiction of ASTM Committee D-30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved Nov. 15, 1994. Published January 1995. Originally
published as C 297 – 52T. Last previous edition C 297 – 61(1988)e1.
2 Annual Book of ASTM Standards, Vol 03.01.
1
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
7. Procedure
7.1 Determine the plan dimensions of the specimens in
millimetres (inches) to a precision of60.5 %.
7.2 Measure the thickness of the specimens in millimetres
(inches) to the nearest 0.025 mm (0.001 in.).
7.3 Apply a tensile load at a constant rate of movement of
the testing machine cross-head at such a rate that the maximum
load will occur between 3 and 6 min (Note 1). One acceptable
test setup is shown in Fig. 1.
7.4 An adhesion failure of the bond to the loading blocks is
not considered a valid failure. A retest shall be performed.
NOTE 1—A suggested rate of cross-head movement is 0.50 mm/min
(0.020 in./min).
8. Calculation
8.1 Calculate the flatwise tensile strength as follows:
s 5
P
A (1)
where:
s = flatwise tensile strength, MPa (psi);
P = ultimate load, N (lb); and
A = cross-sectional area, mm2 (in.2).
9. Report
9.1 The report shall include the following:
9.1.1 Description of test specimens; core material, facings,
core-to-facing adhesive,
9.1.2 Dimensions of test specimens,
9.1.3 Method of bonding specimen to blocks; adhesive, cure
cycle, and pressure,
9.1.4 Specimens conditioning, if any,
9.1.5 Test temperature and specimens time at temperature,
9.1.6 Test machine cross-head loading rate,
9.1.7 Flatwise tensile strength; individual values and aver-
age, and
9.1.8 Description of failure mode; percentage of failure area
of core, adhesive (cohesion or adhesion), or facing (Note 2).
NOTE 2—Failure definitions:
core failure—tensile future of the sandwich core. Pieces of the core are
in the adhesive that bonds the core to the block or facing.
cohesive failure of adhesive—failure in the adhesive layer used to bond
the facing to the core or the block to the core. The adhesive is on the core
and the facing or block.
adhesion failure of adhesive—failure by disbonding of the adhesive to
the core or to the facing or block. No adhesive on the core or on the facing
or block.
facing failure—tensile failure of the facing. Usually by delamination of
composite plies in the case of a fiber-reinforced composite facing.
10. Precision and Bias
10.1 Precision—The precision of the procedure in Test
Method C 297 for measuring sandwich construction flatwise
tensile strengths will be determined in the future.
10.2 Bias—Since there is no accepted reference material
suitable for determining the bias for the procedure in this test
method, bias has not been determined.
11. Keywords
11.1 flatwise tension; sandwich; sandwich construction; ten-
sile strength
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned
in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk
of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the
responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should
make your views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above
address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website
(www.astm.org).
FIG. 1 Flatwise Tension Test Setup
C 297
2
Designation: C 297/C 297M – 04
Standard Test Method for
Flatwise Tensile Strength of Sandwich Constructions 1
This standard is issued under the fixed designation C 297/C 297M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method covers determines the determination of the core flatwise tension tensile strength of the core, the
core-to-facing bond, or the bond between core and facings facing of an assembled sandwich panel. The test consists of subjecting
a sandwich construction to a tensile load normal to the plane of the sandwich, such load being transmitted to the sandwich through
thick loading blocks bonded to the sandwich facings or directly to the core. Permissible core material forms include those with
continuous bonding surfaces (such as balsa wood and foams) as well as those with discontinuous bonding surfaces (such as
honeycomb).
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as the standard. The Within the text
the inch-pound units g are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system
must be a used indeppendently of the other. Coxmbining values from the two systems may result in nonconformance with the
standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:2
C 274 Terminology of Structural Sandwich Constructions
D 792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement
D 883 Terminology Relating to Plastics
D 2584 Test Method for Ignition Loss of Cured Reinforced Resins
D 2734 Test Method for Void Content of Reinforced Plastics
D 3039/D 3039M Test Method for Tensile Properties of Polymer Matrix Composite Materials
D 3171 Test Method for Constituent Content of Composite Materials
D 3878 Terminology for Composite Materials
D 5229/D 5229M Test Method for Moisture Absorption Properties and Equilibrium Conditioning of Polymer Matrix Composite
Materials
E 4 Practices for Force Verification of Testing Machines
E 6 Terminology Relating to Methods of Mechanical Testing
E 122 Practice for Choice of Sample Size to Estimate a Measure of Quality for a Lot or Process
E 177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E 456 Terminology Relating to Quality and Statistics
E 1309 Guide for Identification of Fiber-Reinforced Polymer-Matrix Composite Materials in Databases
E 1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in Databases
E 1471 Guide for Identification of Fibers, Fillers, and Core Materials in Computerized Material Property Databases
3. STerminology
3.1 Definitions—Terminology D 3878 deficnes terms relatincg to high-modulus fibers andUse
1 This test method is under the jurisdiction of ASTM Committee D-30 on Composite Materials and is the direct responsibility of Subcommittee D30.09 on Sandwich
Construction.
Current edition approved Nov. 15, 1994. May 1, 2004. Published January 1995. May 2004. Originally published as C 297 – 52T. approved in 1952. Last previous edition
C 297 – 61(1988)e1. approved in 1999 as C 297 – 94 (1999).
2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. ForAnnual Book of ASTM Standards,
Vol 03.01. volume information, refer to the standard’s Document Summary page on the ASTM website.
C 297 – 94 (1999)
2
3.1 For a their composites. Terminology C 274 defines terms relating to structural sandwich panel constructions. Terminology
D 883 defines terms relating to function properly, the facings must have a sufficient bond plastics. Terminology E 6 defines terms
relating to the core.
3.2 This test method provides information on how well the facings are bonded mechanical testing. Terminology E 456 and
Practice E 177 define terms relating to statistics. In the event of a conflict between terms, Terminology D 3878 shall have
precedence over the other terminologies.
3.2 Symbols:
A = cross-sectional area of a test specimen
CV= coefficient of variation statistic of a sample population for a given property (in percent)
Fz
ftu = ultimate flatwise tensile strength
Pmax= maximum force carried by test specimen before failure
Sn-1 = standard deviation statistic of a sample population for a given property
x1 = test result for an individual specimen from the core. It is mainly used as sample population for a quality control test given
property
x̄ = mean or average (estimate of mean) of a sample population for bonded sandwich panels. a given property
4. Summary of Test Method
4.1 This test method consists of subjecting a sandwich construction to a uniaxial tensile force normal to the plane of the
sandwich. The force is transmitted to the sandwich through thick loading blocks, which are bonded to the sandwich facings or
directly to the core.
4.2 The only acceptable failure modes for flatwise tensile strength are those which are internal to the sandwich construction.
Failure of the loading block-to-sandwich bond is not an acceptable failure mode.
5. Significance and Use
5.1 In a sandwich panel, core-to-facing bond integrity is necessary to maintain facing stability and permit load transfer between
the facings and core. This test method can be used to provide information on the strength and quality of core-to-facing bonds. It
can also be used to produce flatwise tensile strength data for the core material. While it is primarily used as a quality control test
for bonded sandwich panels, it can also be used to produce flatwise tensile strength data for structural design properties, material
specifications, and research and development applications.
5.2 Factors that influence the flatwise tensile strength and shall therefore be reported include the following: facing material, core
material, adhesive material, methods of material fabrication, facing stacking sequence and overall thickness, core geometry (cell
size), core density, adhesive thickness, specimen geometry, specimen preparation, specimen conditioning, environment of testing,
specimen alignment, loading procedure, speed of testing, facing void content, adhesive void content, and facing volume percent
reinforcement. Properties that may be derived from this test method include flatwise tensile strength.
6. Interferences
6.1 Material and Specimen Preparation—Poor material fabrication practices, lack of control of fiber alignment, and damage
induced by improper specimen machining are known causes of high data scatter in composites in general. Specific material factors
that affect sandwich composites include variability in core density and degree of cure of resin in both facing matrix material and
core bonding adhesive. Important aspects of sandwich panel specimen preparation that contribute to data scatter are incomplete
or nonuniform core bonding to facings, misalignment of core and facing elements, the existence of joints, voids or other core and
facing discontinuities, out-of-plane curvature, facing thickness variation, and surface roughness.
6.2 System Alignment—Excessive bending will cause premature failure. Every effort should be made to eliminate excess
bending from the test system. Bending may occur as a result of misaligned grips, poor specimen preparation, or poor alignment
of the bonding blocks and loading fixture. If there is any doubt as to the alignment inherent in a given test machine, then the
alignment should be checked as discussed in Test Method D 3039/D 3039M.
6.3 Geometry—Specific geometric factors that affect sandwich flatwise tensile strength include core cell geometry, core
thickness, specimen shape (square or circular), adhesive thickness, facing thickness, and facing per-ply thickness.
6.4 Environment—Results are affected by the environmental conditions under which the tests are conducted. Specimens tested
in various environments can exhibit significant differences in both strength behavior and failure mode. Critical environments must
be assessed independently for each facing, adhesive and core material tested.
6.5 Conditioning—As it is inappropriate to bond a moisture-conditioned specimen to the bonding blocks, it is necessary to
perform the bonding operation prior to such conditioning. The presence of the bonding blocks will affect the degree of moisture
intake into the specimen, in comparison to a non-bonded sample.
7. Apparatus
4.1 Test machine, capable of maintaining
7.1 Micrometers—The micrometer(s) shall use a controlled loading rate and indicating 4- to 5-mm [0.16- to 0.20-in.] nominal
diameter ball-interface on irregular surfaces such as the load with an accuracy bag-side of61 % of the indicated value. a facing
C 297/C 297M – 04
3
laminate, and a flat anvil interface on machined edges or very smooth-tooled surfaces. The accuracy of the test machine
instrument(s) shall be v suitable for readifng to within 1 % of the sample length, width and thickness. For typical speccimen
geometrdies, anc instrument with Practices E 4.
4.2 an accuracy of625 mm [60.001 in.] is desirable for thickness, length and width measurement.
7.2 Loading f Fixtures, t—The loading fixtures shall be self-aligning and shall not apply eccentric loads. A satisfactory type of
apparatus is shown in Fig. 1. The loading blocks shall be sufficiently stiff to keep the bonded core or facings essentially flat under
load. Loading blocks 40 to 50 mm ( [1.5 to 2.0 in.)] thick have been found to perform satisfactorily. Permissible tolerances for
the loading blocks (along with alignment requirements) are provided in Fig. 2.
47.3 Testing Machine—The testing machine shall be in accordance with Practices E 4 and shall satisfy the following
requirements:
7.3.1 Ter,sting Magchine, Configuration—The testing machine shall have both an essentipally stationary head and a movable
head.
7.3.2 Drive Mechanism,—The testing machine drive mechanism shall be capable of measuring accurately imparting to 0.025
mm (0.001 in.).
5. Test the movable head a controlled velocity with respect to the stationary head. The velocity of the movable head
shall be capable of being regulated in accordance with 11.6.
7.3.3 Load Indicator—The testing machine load-sensing device shall be capable of indicating the total force being carried by
the test specimen. This device shall be essentially free from inertia lag at the specified rate of testing and shall indicate the force
with an accuracy over the force range(s) of interest of within61 % of the indicated value.
7.4 Conditioning Chamber—When conditioning materials at non-laboratory environments, a temperature/vapor-level con-
trolled environmental conditioning chamber is required that shall be capable of maintaining the required temperature to within
63°C [65°F]and the required relative humidity level to within63 %. Chamber conditions shall be monitored either on an
automated continuous basis or on a manual basis at regular intervals.
7.5 Environmental Test Chamber—An environmental test chamber is required for test environments other than ambient testing
laboratory conditions. This chamber shall be capable of maintaining the gage section of the test specimen at the required test
environment during the mechanical test.
8. Sampling and Test Specimens
58.1 Sampling—Test at least five specimens per tesht condition unless valid results can be gained through the use of fewer
FIG. 1 Flatwise Tension Test Setup
C 297/C 297M – 04
4
specimens, as in the case of a designed experiment. For statistically significant data, consult the procedures outlined in Practice
E 122. Report the method of sampling.
8.2 Geometry—Test specimens shall have a square or round circular cross-section, and shall be equal in thickness to the
sandwich panel thickness. All dimensions shall be measured to the nearest 0.25 mm (0.01 in.). Minimum specimen facing areas
for various types of core materials are given below:
5.1.1 For continuous cores, such as follows:
8.2.1 Continuous Bonding Surfaces (for example, balsa wood and foams, the wood, foams)—The minimum facing area of the
specimen shall be 625 mm2 (1 [1.0 in.2).
5.1.2 For open-celled cores, such as honeycomb, having].
8.2.2 Discontinuous Cellular Bonding Surfaces (for example, honeycomb)—The required facing area of the specimen is
dependent upon the cell size, to ensure a minimum number of cells less than 6 mm (0.5 in.), are tested. Minimum facing areas are
recommended in Table 1 for the more common cell sizes. These are intended to provide approximately 60 cells minimum in the
test specimen. The largest facing area shall be 2600 listed in the table (5625 mm2(4 [9.0 in.2), and]) is a practical maximum for
this test method. Cores with cell s 6izes larger than 9 mm ( [0.375 in.)] may require a smaller number of cells to be tested in the
specimen.
8.3 Specimen Preparation and Machining—Specimen preparation is extremely important for this test method. Take precautions
when cutting specimens from large panels to avoid notches, undercuts, rough or g uneven surfaces, or delaminations due to
inappropriate machining methods. Obtain final dimensions by water-lubricated precision sawing, milling, or grinding. The use of
diamond tooling has been found to be extremely effective for many material systems. Edges should be flat and parallel within the
m specified tolerances. Record and report the specimen cumtting preparation method.
FIG. 2 Permissible Bonded Assembly Tolerances
TABLE 1 Recommended Minimum Specimen Facing Area
Minimum Cell Size
(mm [in.])
Maximum Cell Size
(mm [in.])
Minimum Facing Area
(mm2 [in.2])
- 3.0 [0.125] 625 [1.0]
3.0 [0.125] 6.0 [0.250] 2500 [4.0]
6.0 [0.250] 9.0 [0.375] 5625 [9.0]
C 297/C 297M – 04
5
8.4 Labeling—Label the test specimens so that they will be 5800 mm2 (9 in.2).
5.2 The distinct from each other and traceable back to the panel of origin, and will neither influence the test nor be affected by
it.
8.5 Loading Fixture Bonding—The loading blocks shall be bonded to the core or facings of the test specimen using a suitable
adhesive. Ideally, To minimize thermal exposure effects upon the bonding temperature and pressure shall not appreciably affect the
existing bond between facing and core. The bonding pressure shall not be greater than core-to-facing bonds, it is recommended
that the original facing to core bonding pressure. If possible, the assembly bonding temperature shall be at room temperature, or
at least 28°C (50°F) [50°F] lower than that at which the sandwich was originally bonded.
5.3 The number of test specimens and bonded. Similarly, the method of their selection depend on assembly bonding pressure
shall not be greater than the original facing-to-core bonding pressurpoe. Permissible tolerances for the particular test under
consideration, and no general rule can be given to cover bonded assembly (along with alignment requirements) are provided in
Fig. 2.
9. Calibration
9.1 The accuracy of all cases. However, when specimens measuring equipment shall have certified calibrations that are to be
used for acceptance tests, current at least five specimens shall be tested.
6. the time of use of the equipment.
10. Conditioning
6.1 When the physical properties
10.1 Standard Conditioning Procedure—Unless a different environment is specified as part of the component materials are
affected by moisture, bring experiment, condition the test specimens to constant weight (61 %) before testing, preferably in a
conditioning room accordance with temperature Procedure C of Test Method D 5229/D 5229M, and humidity control, store and
make the tests, preferably, in a room under the same conditions. A temperature of 23 test at standard laboratory atmosphere (23
6 3°C (73 [736 5°F)] and a relative humidity of 506 5 % are recommended.
7. relative humidity).
11. Procedure
7.1 Determine the plan dimensions of the specimens in millimetres (inches)
11.1 Parameters to a precision of60.5 %.
7.2 Measure the thickness of the specimens in millimetres (inches) to the nearest 0.025 mm (0.001 in.).
7.3 Apply a tensile load at a constant rate of movement of the testing machine cross-head at such a rate that the maximum load
will occur between 3 Be Specified Before Test:
11.1.1 The specimen sampling method, specimen geometry, and 6 min (Note 1). One acceptable test setup is shown in Fig. 1.
7.4 An adhesion failure of the bond to the loading blocks is not considered a valid failure. A retest shall be performed.
conditioning travelers (if required).
11.1.2 The properties and data reporting format desired.
NOTE 1—ADetermine specific material property, accuracy, and data reporting requirements prior to test for proper selection of instrumentation and data
recording equipment. Estimate the specimen strength to aid in transducer selection, calibration of equipment, and determination of equipment settings.
11.1.3 The environmental conditioning test parameters.
11.1.4 If performed, sampling method, specimen geometry, and test parameters used to determine facing density and
reinforcement volume.
11.2 General Instructions:
11.2.1 Report any deviations from this test method, whether intentional or inadvertent.
11.2.2 If specific gravity, density, facing reinforcement volume, or facing void volume are to be reported, then obtain these
samples from the same panels being tested. Specific gravity and density may be evaluated in accordance with Test Methods D 792.
Volume percent of composite facing constituents may be evaluated by one of the matrix digestion procedures of Test Method
D 3171, or, for certain reinforcement materials such as glass and ceramics, by the matrix burn-off technique in accordance with
Test Method D 2584. The void content equations of Test Method D 2734 are applicable to both Test Method D 2584 and the matrix
digestion procedures.
11.2.3 Following final specimen machining, but before conditioning and testing, measure the specimen length and width or
diameter. The accuracy of these measurements shall be within 0.5 % of the dimension. Measure the specimen thickness; the
accuracy of this measurement shall be within625 mm [60.001 in.]. Record the dimensions to three significant figures in units
of millimetres [inches].
11.3 Bond the specimen to the bonding blocks, in accordance with the requirements of 8.5.
11.4 Condition the bonded specimens as required. Store the specimens in the conditioned environment until test time, if the test
environment is different than the conditioning environment.
C 297/C 297M – 04
6
11.5 Following final specimen conditioning, but before testing, re-measure the specimen length and width or diameter as in
11.2.3.
11.6 Speed of Testing—Set the speed of testing so as to produce failure within 3 to 6 min. If the ultimate strength of the material
cannot be reasonablyestimated, initial trials should be conducted using standard speeds until the ultimate strength of the material
and the compliance of the system are known, and speed of testing can be adjusted. The suggested standard head displacement rate
of cross-head movement is 0.50 mm/min ( [0.020 in./min].
11.7 Test Environment—If possible, test the specimen under the same fluid exposure level used for conditioning. However, cases
such as elevated temperature testing of a moist specimen place unrealistic requirements on the capabilities of common testing
machine environmental chambers. In such cases, the mechanical test environment may need to be modified, for example, by testing
at elevated temperature with no fluid exposure control, but with a specified limit on time to failure from withdrawal from the
conditioning chamber. Record any modifications to the test environment.
11.8 Specimen Installation—Install the specimen/bonding block assembly into the test machine test fixture.
11.9 Loading—Apply a tensile force to the specimen at the specified rate while recording data. Load the specimen until rupture.
11.10 Data Recording—Record force versus head displacement continuously, or at frequent regular intervals. Record the
maximum force, the failure force, and the head displacement at, or as near as possible to, the moment of rupture.
11.11 Failure Modes—Adhesive failures that occur at the bond to the loading blocks are not acceptable failure modes and the
data shall be noted as invalid. The following failure modes are considered to be acceptable:
11.11.1 Core Failure—Tensile failure of the sandwich core. Pieces of the core may remain in the adhesive that bonds the core
to the block or facing.
11.11.2 Cohesive Failure of Core-Facing Adhesive—Failure in the adhesive layer used to bond the facing to the core, with
adhesive generally remaining on both the facing and core surfaces.
11.11.3 Adhesive Failure of Core-Facing Adhesive—Failure in the adhesive layer used to bond the facing to the core, with
adhesive generally remaining on either the facing or the core surface, but not both.
11.11.4 Facing Tensile Failure—Tensile failure of the facing, usually by delamination of the composite plies in the case of a
fiber-reinforced composite facing.
12. Validation
12.1 Values for ultimate properties shall not be calculated for any specimen that breaks at some obvious flaw, unless such flaw
constitutes a variable being studied. Retests shall be performed for any specimen on which values are not calculated.
12.2 A significant fraction of failures in a sample population occurring at the bond(s) to the loading blocks shall be cause to
reexamine the means of force introduction into the material. Factors considered should include the fixture alignment, adhesive
material, specimen surface characteristics, and uneven machining of specimen ends.
813. Calculation
813.1 Ultimate Strength—Calculate the ultimate flatwise tensile strength as follows: using Eq 1 and report the results to three
significant figures.
s 5
P
A (1)
Fz
ftu 5 Pmax / A (1)
where:
sFz
ftu = ultimate flatwise tensile strength, MPa (psi); [psi],
Pmax = ultimate load, force prior to failure, N (lb); [lbf], and
A = cross-sectional area, mm2 ([in.2).].
13.2 Statistics—For each series of tests calculate the average value, standard deviation, and coefficient of variation (in percent)
for ultimate flatwise tensile strength:
x̄ 5 ~(
i51
n
x1! (2)
Sn21 5Œ~(
i51
n
x1
2 2 n x̄2! / ~n 2 1! (3)
CV5 1003 Sn21 / x̄ (4)
where:
x̄ = sample mean (average),
Sn-1 = sample standard deviation,
CV = sample coefficient of variation, %,
n = number of specimens, and
x1 = measured or derived property.
C 297/C 297M – 04
7
914. Report
9.1 The report shall include
14.1 Report the following:
9.1.1 Description of test specimens; core material, facings, core-to-facing adhesive,
9.1.2 Dimensions of test specimens,
9.1.3 Method of bonding specimen following information, or references pointing to blocks; adhesive, cure cycle, and pressure,
9.1.4 Specimens conditioning, if any,
9.1.5 Test temperature and specimens time at temperature,
9.1.6 Test machine cross-head loading rate,
9.1.7 Flatwise tensile strength; individual values and average, and
9.1.8 Description other documentation containing this information, to the maximum extent applicable (reporting of failure
mode; percentage items beyond the control of failure area of core, adhesive (cohesion a given testing laboratory, such as might
occur with material details or adhesion), or facing (Note 2). panel fabrication parameters, shall be the responsibility of the
requestor):
NOTE 2—Failure definitions:
core failure—tensile future 2—Guides E 1309, E 1434 and E 1471 contain data reporting recommendations for composite materials and composite
materials mechanical testing.
14.1.1 The revision level or date of the sandwich core. Pieces issue of this test method.
14.1.2 The name(s) of the core are in the adhesive that bonds the core test operator(s).
14.1.3 Any variations to this te bst method, anomalies noticked during testing, or facing.
cohesive failure equipment problems occurring during testing.
14.1.4 Identification of adhesive—failure in all the adhesive layer used materials consistuent to bond the sandwich panel
specimen tested, including for each: material specification, material type, manufacturer’s material designation, manufacturer’s
batch or lot number, source (if not from manufacturer), date of certification, expiration of certification, facing to the core filament
diameter, tow or yarn filament count and twist, sizing, form or weave, fiber areal weight, matrix type, facing matrix content and
volatiles content, ply orientation and stacking sequence of the block facings.
14.1.5 Description of the fabrication steps used to prepare the core. The adhesive is on sandwich panel including: fabrication
start date, fabrication end date, process specification, cure cycle, consolidation method, and a description of the c equipment used.
14.1.6 Ply orientation and stacking sequence of the facing or block.
adhesion failure laminate.
14.1.7 If requested, report facing density, volume percent reinforcement, and void content test methods, specimen sampling
method and geometries, test parameters and test results.
14.1.8 Results of adhesive—failure by disbonding any nondestructive evaluation tests.
14.1.9 Method of preparing the test specimen, including specimen labeling scheme and method, specimen geometry, samplivng
method, and specimen cutting method.
14.1.10 Calibration dates and methods for all measurements and test equipment.
14.1.11 Details of loading blocks and apparatus, including dimensions and material used.
14.1.12 Type of test machine, alignment results, and data acquisition sampling rate and equipment type.
14.1.13 Measured length and width (or diameter) and thickness for each specimen (prior to and afther conditioning, if
appreopriate).
14.1.14 Weight of specimen.
14.1.15 Method of bonding specimens to blocks; adhesive, cure cycle, and pressure.
14.1.16 Conditioning parameters and results.
14.1.17 Relative humidity and temperature of the facing or block. No adhesive on the core or on the facing or block.
facing failure—tensile failure testing laboratory.
14.1.18 Environment of the facing. Usually by delamination test machine environmental chamber (if used) and soak time at
environment.
14.1.19 Number of specoimens tested.
14.1.20 Speed of testing.
14.1.21 Individual ultimate p flatwise tensile strengths and average value, standard deviation, and coefficient of variation (in
percent) for the population.
14.1.22 Force versus crosshead displacement data for each specimen so evaluated.
14.1.23 Failure mode, location of a fiber-reinforced composite facing.
C 297/C 297M – 04
8
10. failure, percentage of failure area of core, adhesive (cohesive or adhesive failure), or facing for each specimen.
15. Precision and Bias
105.1 Precision—The precision of the procedure in Test Method C 297 data requiredfor measuring sandwich construction
flatwise tensile strengths will be determined in the development ofu a precision stuatement is not available for this method.
105.2 Bias—Since there is no accepted reference material suitable—Bias cannot be determined for determining the bias for the
procedure in this test method, bias has not been determined.
11. method as no acceptable reference standards exist.
16. Keywords
116.1 core; facing; flatwise tension; sandwich; sandwich construction; tensile strength
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned
in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk
of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the
responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should
make your views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above
address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website
(www.astm.org).
C 297/C 297M – 04
9
Designation: C 297/C 297M – 04
Standard Test Method for
Flatwise Tensile Strength of Sandwich Constructions 1
This standard is issued under the fixed designation C 297/C 297M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method determines the flatwise tensile strength
of the core, the core-to-facing bond, or the facing of an
assembled sandwich panel. Permissible core material forms
include those with continuous bonding surfaces (such as balsa
wood and foams) as well as those with discontinuous bonding
surfaces (such as honeycomb).
1.2 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. Within the text the
inch-pound units are shown in brackets. The values stated in
each system are not exact equivalents; therefore, each system
must be used independently of the other. Combining values
from the two systems may result in nonconformance with the
standard.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:2
C 274 Terminology of Structural Sandwich Constructions
D 792 Test Methods for Density and Specific Gravity (Rela-
tive Density) of Plastics by Displacement
D 883 Terminology Relating to Plastics
D 2584 Test Method for Ignition Loss of Cured Reinforced
Resins
D 2734 Test Method for Void Content of Reinforced Plas-
tics
D 3039/D 3039M Test Method for Tensile Properties of
Polymer Matrix Composite Materials
D 3171 Test Method for Constituent Content of Composite
Materials
D 3878 Terminology for Composite Materials
D 5229/D 5229M Test Method for Moisture Absorption
Properties and Equilibrium Conditioning of Polymer Ma-
trix Composite Materials
E 4 Practices for Force Verification of Testing Machines
E 6 Terminology Relating to Methods of Mechanical Test-
ing
E 122 Practice for Choice of Sample Size to Estimate a
Measure of Quality for a Lot or Process
E 177 Practice for Use of the Terms Precision and Bias in
ASTM Test Methods
E 456 Terminology Relating to Quality and Statistics
E 1309 Guide for Identification of Fiber-Reinforced
Polymer-Matrix Composite Materials in Databases
E 1434 Guide for Recording Mechanical Test Data of Fiber-
Reinforced Composite Materials in Databases
E 1471 Guide for Identification of Fibers, Fillers, and Core
Materials in Computerized Material Property Databases
3. Terminology
3.1 Definitions—Terminology D 3878 defines terms relating
to high-modulus fibers and their composites. Terminology
C 274 defines terms relating to structural sandwich construc-
tions. Terminology D 883 defines terms relating to plastics.
Terminology E 6 defines terms relating to mechanical testing.
Terminology E 456 and Practice E 177 define terms relating to
statistics. In the event of a conflict between terms, Terminology
D 3878 shall have precedence over the other terminologies.
3.2 Symbols:
A = cross-sectional area of a test specimen
CV= coefficient of variation statistic of a sample population
for a given property (in percent)
Fz
ftu = ultimate flatwise tensile strength
Pmax= maximum force carried by test specimen before
failure
Sn-1 = standard deviation statistic of a sample population for
a given property
x1 = test result for an individual specimen from the sample
population for a given property
x̄ = mean or average (estimate of mean) of a sample popu-
lation for a given property
1 This test method is under the jurisdiction of ASTM Committee D30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved May 1, 2004. Published May 2004. Originally
approved in 1952. Last previous edition approved in 1999 as C 297 – 94 (1999).
2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. ForAnnual Book of ASTM
Standardsvolume information, refer to the standard’s Document Summary page on
the ASTM website.
1
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
4. Summary of Test Method
4.1 This test method consists of subjecting a sandwich
construction to a uniaxial tensile force normal to the plane of
the sandwich. The force is transmitted to the sandwich through
thick loading blocks, which are bonded to the sandwich facings
or directly to the core.
4.2 The only acceptable failure modes for flatwise tensile
strength are those which are internal to the sandwich construc-
tion. Failure of the loading block-to-sandwich bond is not an
acceptable failure mode.
5. Significance and Use
5.1 In a sandwich panel, core-to-facing bond integrity is
necessary to maintain facing stability and permit load transfer
between the facings and core. This test method can be used to
provide information on the strength and quality of core-to-
facing bonds. It can also be used to produce flatwise tensile
strength data for the core material. While it is primarily used as
a quality control test for bonded sandwich panels, it can also be
used to produce flatwise tensile strength data for structural
design properties, material specifications, and research and
development applications.
5.2 Factors that influence the flatwise tensile strength and
shall therefore be reported include the following: facing
material, core material, adhesive material, methods of material
fabrication, facing stacking sequence and overall thickness,
core geometry (cell size), core density, adhesive thickness,
specimen geometry, specimen preparation, specimen condi-
tioning, environment of testing, specimen alignment, loading
procedure, speed of testing, facing void content, adhesive voidcontent, and facing volume percent reinforcement. Properties
that may be derived from this test method include flatwise
tensile strength.
6. Interferences
6.1 Material and Specimen Preparation—Poor material
fabrication practices, lack of control of fiber alignment, and
damage induced by improper specimen machining are known
causes of high data scatter in composites in general. Specific
material factors that affect sandwich composites include vari-
ability in core density and degree of cure of resin in both facing
matrix material and core bonding adhesive. Important aspects
of sandwich panel specimen preparation that contribute to data
scatter are incomplete or nonuniform core bonding to facings,
misalignment of core and facing elements, the existence of
joints, voids or other core and facing discontinuities, out-of-
plane curvature, facing thickness variation, and surface rough-
ness.
6.2 System Alignment—Excessive bending will cause pre-
mature failure. Every effort should be made to eliminate excess
bending from the test system. Bending may occur as a result of
misaligned grips, poor specimen preparation, or poor align-
ment of the bonding blocks and loading fixture. If there is any
doubt as to the alignment inherent in a given test machine, then
the alignment should be checked as discussed in Test Method
D 3039/D 3039M.
6.3 Geometry—Specific geometric factors that affect sand-
wich flatwise tensile strength include core cell geometry, core
thickness, specimen shape (square or circular), adhesive thick-
ness, facing thickness, and facing per-ply thickness.
6.4 Environment—Results are affected by the environmen-
tal conditions under which the tests are conducted. Specimens
tested in various environments can exhibit significant differ-
ences in both strength behavior and failure mode. Critical
environments must be assessed independently for each facing,
adhesive and core material tested.
6.5 Conditioning—As it is inappropriate to bond a
moisture-conditioned specimen to the bonding blocks, it is
necessary to perform the bonding operation prior to such
conditioning. The presence of the bonding blocks will affect
the degree of moisture intake into the specimen, in comparison
to a non-bonded sample.
7. Apparatus
7.1 Micrometers—The micrometer(s) shall use a 4- to 5-mm
[0.16- to 0.20-in.] nominal diameter ball-interface on irregular
surfaces such as the bag-side of a facing laminate, and a flat
anvil interface on machined edges or very smooth-tooled
surfaces. The accuracy of the instrument(s) shall be suitable for
reading to within 1 % of the sample length, width and
thickness. For typical specimen geometries, an instrument with
an accuracy of625 mm [60.001 in.] is desirable for thickness,
length and width measurement.
7.2 Loading Fixtures—The loading fixtures shall be self-
aligning and shall not apply eccentric loads. A satisfactory type
of apparatus is shown in Fig. 1. The loading blocks shall be
FIG. 1 Flatwise Tension Test Setup
C 297/C 297M – 04
2
sufficiently stiff to keep the bonded core or facings essentially
flat under load. Loading blocks 40 to 50 mm [1.5 to 2.0 in.]
thick have been found to perform satisfactorily. Permissible
tolerances for the loading blocks (along with alignment re-
quirements) are provided in Fig. 2.
7.3 Testing Machine—The testing machine shall be in
accordance with Practices E 4 and shall satisfy the following
requirements:
7.3.1 Testing Machine Configuration—The testing machine
shall have both an essentially stationary head and a movable
head.
7.3.2 Drive Mechanism—The testing machine drive mecha-
nism shall be capable of imparting to the movable head a
controlled velocity with respect to the stationary head. The
velocity of the movable head shall be capable of being
regulated in accordance with 11.6.
7.3.3 Load Indicator—The testing machine load-sensing
device shall be capable of indicating the total force being
carried by the test specimen. This device shall be essentially
free from inertia lag at the specified rate of testing and shall
indicate the force with an accuracy over the force range(s) of
interest of within61 % of the indicated value.
7.4 Conditioning Chamber—When conditioning materials
at non-laboratory environments, a temperature/vapor-level
controlled environmental conditioning chamber is required that
shall be capable of maintaining the required temperature to
within 63°C [65°F] and the required relative humidity level
to within 63 %. Chamber conditions shall be monitored either
on an automated continuous basis or on a manual basis at
regular intervals.
7.5 Environmental Test Chamber—An environmental test
chamber is required for test environments other than ambient
testing laboratory conditions. This chamber shall be capable of
maintaining the gage section of the test specimen at the
required test environment during the mechanical test.
8. Sampling and Test Specimens
8.1 Sampling—Test at least five specimens per test condi-
tion unless valid results can be gained through the use of fewer
specimens, as in the case of a designed experiment. For
statistically significant data, consult the procedures outlined in
Practice E 122. Report the method of sampling.
8.2 Geometry—Test specimens shall have a square or cir-
cular cross-section, and shall be equal in thickness to the
sandwich panel thickness. Minimum specimen facing areas for
various types of core materials are as follows:
8.2.1 Continuous Bonding Surfaces (for example, balsa
wood, foams)—The minimum facing area of the specimen
shall be 625 mm2 [1.0 in.2].
8.2.2 Discontinuous Cellular Bonding Surfaces (for ex-
ample, honeycomb)—The required facing area of the specimen
is dependent upon the cell size, to ensure a minimum number
of cells are tested. Minimum facing areas are recommended in
Table 1 for the more common cell sizes. These are intended to
FIG. 2 Permissible Bonded Assembly Tolerances
C 297/C 297M – 04
3
provide approximately 60 cells minimum in the test specimen.
The largest facing area listed in the table (5625 mm2 [9.0 in.2])
is a practical maximum for this test method. Cores with cell
sizes larger than 9 mm [0.375 in.] may require a smaller
number of cells to be tested in the specimen.
8.3 Specimen Preparation and Machining—Specimen
preparation is extremely important for this test method. Take
precautions when cutting specimens from large panels to avoid
notches, undercuts, rough or uneven surfaces, or delaminations
due to inappropriate machining methods. Obtain final dimen-
sions by water-lubricated precision sawing, milling, or grind-
ing. The use of diamond tooling has been found to be
extremely effective for many material systems. Edges should
be flat and parallel within the specified tolerances. Record and
report the specimen cutting preparation method.
8.4 Labeling—Label the test specimens so that they will be
distinct from each other and traceable back to the panel of
origin, and will neither influence the test nor be affected by it.
8.5 Loading Fixture Bonding—The loading blocks shall be
bonded to the core or facings of the test specimen using a
suitable adhesive. To minimize thermal exposure effects upon
the existing core-to-facing bonds, it is recommended that the
assembly bonding temperature be at room temperature, or at
least 28°C [50°F] lower than that at which the sandwich was
originally bonded. Similarly, the assembly bonding pressure
shall not be greater than the original facing-to-core bonding
pressure. Permissible tolerances for the bonded assembly
(along with alignment requirements) are provided in Fig. 2.
9. Calibration
9.1 The accuracy of all measuring equipment shall have
certified calibrations that are current at the time of use of the
equipment.
10. Conditioning
10.1 Standard Conditioning Procedure—Unless a different
environment is specified as part of the experiment, condition
the test specimens in accordance with Procedure C of Test
Method D 5229/D 5229M, and store and test at standard
laboratory atmosphere (236 3°C [736 5°F] and 506 5 %
relative humidity).
11. Procedure
11.1 Parameters to Be Specified Before Test:
11.1.1 The specimen sampling method, specimen geometry,
and conditioning travelers (if required).
11.1.2 The properties and data reporting format desired.
NOTE 1—Determine specific material property, accuracy, and data
reporting requirements prior to test for proper selection of instrumentation
and data recording equipment. Estimate the specimen strength to aid in
transducer selection, calibration of equipment, and determination of
equipment settings.
11.1.3 The environmental conditioning test parameters.
11.1.4 If performed, sampling method, specimen geometry,
and test parameters used to determine facing density and
reinforcement volume.
11.2 General Instructions:
11.2.1 Report any deviations from this test method, whether
intentional or inadvertent.
11.2.2 If specific gravity, density, facing reinforcement vol-
ume, or facing void volume are to be reported, then obtain
these samples from the same panels being tested. Specific
gravity and density may be evaluated in accordance with Test
Methods D 792. Volume percent of composite facing constitu-
ents may be evaluated by one of the matrix digestion proce-
dures of Test Method D 3171, or, for certain reinforcement
materials such as glass and ceramics, by the matrix burn-off
technique in accordance with Test Method D 2584. The void
content equations of Test Method D 2734 are applicable to both
Test Method D 2584 and the matrix digestion procedures.
11.2.3 Following final specimen machining, but before
conditioning and testing, measure the specimen length and
width or diameter. The accuracy of these measurements shall
be within 0.5 % of the dimension. Measure the specimen
thickness; the accuracy of this measurement shall be within
625 mm [60.001 in.]. Record the dimensions to three signifi-
cant figures in units of millimetres [inches].
11.3 Bond the specimen to the bonding blocks, in accor-
dance with the requirements of 8.5.
11.4 Condition the bonded specimens as required. Store the
specimens in the conditioned environment until test time, if the
test environment is different than the conditioning environ-
ment.
11.5 Following final specimen conditioning, but before
testing, re-measure the specimen length and width or diameter
as in 11.2.3.
11.6 Speed of Testing—Set the speed of testing so as to
produce failure within 3 to 6 min. If the ultimate strength of the
material cannot be reasonably estimated, initial trials should be
conducted using standard speeds until the ultimate strength of
the material and the compliance of the system are known, and
speed of testing can be adjusted. The suggested standard head
displacement rate is 0.50 mm/min [0.020 in./min].
11.7 Test Environment—If possible, test the specimen under
the same fluid exposure level used for conditioning. However,
cases such as elevated temperature testing of a moist specimen
place unrealistic requirements on the capabilities of common
testing machine environmental chambers. In such cases, the
mechanical test environment may need to be modified, for
example, by testing at elevated temperature with no fluid
exposure control, but with a specified limit on time to failure
from withdrawal from the conditioning chamber. Record any
modifications to the test environment.
11.8 Specimen Installation—Install the specimen/bonding
block assembly into the test machine test fixture.
11.9 Loading—Apply a tensile force to the specimen at the
specified rate while recording data. Load the specimen until
rupture.
TABLE 1 Recommended Minimum Specimen Facing Area
Minimum Cell Size
(mm [in.])
Maximum Cell Size
(mm [in.])
Minimum Facing Area
(mm2 [in.2])
- 3.0 [0.125] 625 [1.0]
3.0 [0.125] 6.0 [0.250] 2500 [4.0]
6.0 [0.250] 9.0 [0.375] 5625 [9.0]
C 297/C 297M – 04
4
11.10 Data Recording—Record force versus head displace-
ment continuously, or at frequent regular intervals. Record the
maximum force, the failure force, and the head displacement
at, or as near as possible to, the moment of rupture.
11.11 Failure Modes—Adhesive failures that occur at the
bond to the loading blocks are not acceptable failure modes and
the data shall be noted as invalid. The following failure modes
are considered to be acceptable:
11.11.1 Core Failure—Tensile failure of the sandwich core.
Pieces of the core may remain in the adhesive that bonds the
core to the block or facing.
11.11.2 Cohesive Failure of Core-Facing Adhesive—
Failure in the adhesive layer used to bond the facing to the
core, with adhesive generally remaining on both the facing and
core surfaces.
11.11.3 Adhesive Failure of Core-Facing Adhesive—Failure
in the adhesive layer used to bond the facing to the core, with
adhesive generally remaining on either the facing or the core
surface, but not both.
11.11.4 Facing Tensile Failure—Tensile failure of the fac-
ing, usually by delamination of the composite plies in the case
of a fiber-reinforced composite facing.
12. Validation
12.1 Values for ultimate properties shall not be calculated
for any specimen that breaks at some obvious flaw, unless such
flaw constitutes a variable being studied. Retests shall be
performed for any specimen on which values are not calcu-
lated.
12.2 A significant fraction of failures in a sample population
occurring at the bond(s) to the loading blocks shall be cause to
reexamine the means of force introduction into the material.
Factors considered should include the fixture alignment, adhe-
sive material, specimen surface characteristics, and uneven
machining of specimen ends.
13. Calculation
13.1 Ultimate Strength—Calculate the ultimate flatwise ten-
sile strength using Eq 1 and report the results to three
significant figures.
Fz
ftu 5 Pmax / A (1)
where:
Fz
ftu = ultimate flatwise tensile strength, MPa [psi],
Pmax = ultimate force prior to failure, N [lbf], and
A = cross-sectional area, mm2 [in.2].
13.2 Statistics—For each series of tests calculate the aver-
age value, standard deviation, and coefficient of variation (in
percent) for ultimate flatwise tensile strength:
x̄ 5 ~(
i51
n
x1! (2)
Sn21 5Œ~(
i51
n
x1
2 2 n x̄2! / ~n 2 1! (3)
CV5 1003 Sn21 / x̄ (4)
where:
x̄ = sample mean (average),
Sn-1 = sample standard deviation,
CV = sample coefficient of variation, %,
n = number of specimens, and
x1 = measured or derived property.
14. Report
14.1 Report the following information, or references point-
ing to other documentation containing this information, to the
maximum extent applicable (reporting of items beyond the
control of a given testing laboratory, such as might occur with
material details or panel fabrication parameters, shall be the
responsibility of the requestor):
NOTE 2—Guides E 1309, E 1434 and E 1471 contain data reporting
recommendations for composite materials and composite materials me-
chanical testing.
14.1.1 The revision level or date of issue of this test method.
14.1.2 The name(s) of the test operator(s).
14.1.3 Any variations to this test method, anomalies noticed
during testing, or equipment problems occurring during testing.
14.1.4 Identification of all the materials consistuent to the
sandwich panel specimen tested, including for each: material
specification, material type, manufacturer’s material designa-
tion, manufacturer’s batch or lot number, source (if not from
manufacturer), date of certification, expiration of certification,
facing filament diameter, tow or yarn filament count and twist,
sizing, form or weave, fiber areal weight, matrix type, facing
matrix content and volatiles content, ply orientation and
stacking sequence of the facings.
14.1.5 Description of the fabrication steps used to prepare
the sandwich panel including: fabrication start date, fabrication
end date, process specification, cure cycle, consolidation
method, and a description of the equipment used.
14.1.6 Ply orientation and stacking sequence of the facing
laminate.
14.1.7 If requested, report facing density, volume percent
reinforcement,and void content test methods, specimen sam-
pling method and geometries, test parameters and test results.
14.1.8 Results of any nondestructive evaluation tests.
14.1.9 Method of preparing the test specimen, including
specimen labeling scheme and method, specimen geometry,
sampling method, and specimen cutting method.
14.1.10 Calibration dates and methods for all measurements
and test equipment.
14.1.11 Details of loading blocks and apparatus, including
dimensions and material used.
14.1.12 Type of test machine, alignment results, and data
acquisition sampling rate and equipment type.
14.1.13 Measured length and width (or diameter) and thick-
ness for each specimen (prior to and after conditioning, if
appropriate).
14.1.14 Weight of specimen.
14.1.15 Method of bonding specimens to blocks; adhesive,
cure cycle, and pressure.
14.1.16 Conditioning parameters and results.
14.1.17 Relative humidity and temperature of the testing
laboratory.
14.1.18 Environment of the test machine environmental
chamber (if used) and soak time at environment.
14.1.19 Number of specimens tested.
C 297/C 297M – 04
5
14.1.20 Speed of testing.
14.1.21 Individual ultimate flatwise tensile strengths and
average value, standard deviation, and coefficient of variation
(in percent) for the population.
14.1.22 Force versus crosshead displacement data for each
specimen so evaluated.
14.1.23 Failure mode, location of failure, percentage of
failure area of core, adhesive (cohesive or adhesive failure), or
facing for each specimen.
15. Precision and Bias
15.1 Precision—The data required for the development of a
precision statement is not available for this method.
15.2 Bias—Bias cannot be determined for this method as no
acceptable reference standards exist.
16. Keywords
16.1 core; facing; flatwise tension; sandwich; sandwich
construction; tensile strength
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned
in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk
of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the
responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should
make your views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above
address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website
(www.astm.org).
C 297/C 297M – 04
6
Designation: C 363 – 00
Standard Test Method for
Delamination Strength of Honeycomb Core Materials 1
This standard is issued under the fixed designation C 363; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the determination of the delami-
nation strength (tensile node-to-node bond strength) of honey-
comb core materials.
1.2 The values stated in SI units are to be regarded as the
standard. The inch-pound units given may be approximate.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
E 4 Practices for Force Verification of Testing Machines2
3. Significance and Use
3.1 The honeycomb node bond strength is a fundamental
property than can be used in determining whether honeycomb
cores can be handled during cutting, machining and forming
without the nodes breaking. The node bond strength is the
tensile load that causes failure of the honeycomb by rupture of
the bond between the nodes. It is usually a peeling-type failure.
3.2 This test method provides a standard method of obtain-
ing honeycomb core node strength data for quality control,
acceptance specification testing, and research and develop-
ment.
4. Apparatus
4.1 Test machine, capable of maintaining a controlled load-
ing rate and indicating the load with an accuracy of61 % of
the indicated value. The accuracy of the test machine shall be
verified in accordance with Practices E 4.
4.2 Grips, of multiple-pin type.
4.3 Micrometer, gage, or caliper, capable of measuring
accurately to 0.025 mm (0.001 in.).
5. Test Specimens
5.1 The test specimens shall be 130 mm (5 in.) wide by 260
mm (10 in.) long with a test section outside the grips of 200
mm (8 in.). The specimen width shall be parallel to the node
bond areas. The thickness of the core slice shall be 12 mm
(0.500 in.) for nonmetallic cores and 16 mm (0.625 in.) for
metallic cores.
5.2 The number of test specimens and the method of their
selection depend on the purpose of the particular test under
consideration, and no general rule can be given to cover all
cases. However, when specimens are to be used for acceptance
tests, at least five specimens shall be tested, and these speci-
mens shall be selected from that portion of the material which
appears to have a maximum of distorted cells or misalignment
of bond areas.
6. Conditioning
6.1 The test specimens may be subjected to any desired
condition before testing. For example, immersion in boiling
water or immersion in solvents.
7. Procedure
7.1 Measure the specimen dimensions to the nearest 0.25
mm (0.01 in.).
7.2 Select pins with the largest diameters that will easily fit
into the honeycomb cells.
7.3 Place the pins in cell rows in the top and bottom portions
of the specimen.
7.4 Fig. 1 shows a fixture that has been satisfactorily used to
hold and load the pins.
7.5 Load the specimen at a constant cross-head movement
of 25 mm/min. (1 in./min.).
7.6 Failure of the core at the pin location is not considered
a valid test. A retest shall be performed.
8. Calculation
8.1 Calculate the delamination strength (node-to-node bond
strength) of the core material as follows:
s 5
P
bt (1)1 This test method is under the jurisdiction of ASTM Committee D-30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved Jan. 10, 2000. Published April 2000. Originally
published as C 363 – 55T. Last previous edition C 363 – 94.
2 Annual Book of ASTM Standards, Vol 03.01.
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
where:
s 5 delamination strength, MPa (psi);
P 5 ultimate tensile load, N (lb);
b 5 initial width of specimen, mm (in.); and
t 5 thickness of specimen, mm (in.)
9. Report
9.1 The report shall include the following:
9.1.1 Description of core material; cell size, density, and
type,
9.1.2 Dimensions of the test specimen,
9.1.3 Any special treatment of core before test such as
boiling water, and so forth,
9.1.4 Test temperature and specimen time at temperature,
9.1.5 Test machine cross-head loading rate,
9.1.6 Delamination strength; individual values and average,
and
9.1.7 Description of failure mode, and where the failure
occurred.
10. Precision and Bias
10.1Precision—The precision of the procedure in Test
Method C 363 for measuring the honeycomb core material
delamination strength is not available.
10.2 Bias—Since there is no accepted reference material
suitable for determining the bias for the procedure in this test
method, bias has not been determined.
11. Keywords
11.1 delamination strength; honeycomb core; node bond
strength
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at
610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org).
FIG. 1 Honeycomb Core Delamination Test Setup
C 363
2
Designation: C 364 – 99
Standard Test Method for
Edgewise Compressive Strength of Sandwich
Constructions 1
This standard is issued under the fixed designation C 364; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the determination of flat struc-
tural sandwich construction compressive properties in a direc-
tion parallel to the sandwich facing plane.
1.2 The values stated in SI units are to be regarded as the
standard. The inch-pound units given in parentheses may be
approximate.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
E 4 Practices for Force Verification of Testing Machines2
3. Significance and Use
3.1 The edgewise compressive strength of short sandwich
construction specimens provides a basis for judging the load-
carrying capacity of the construction in terms of developed
facing stresses as compared to the facing yield stress.
3.2 The sandwich column, no matter how short, usually is
subject to a buckling type of failure unless the facings are so
thick that they themselves are in the short column class. The
failure of the facings manifests itself by wrinkling of the
facing, in which the core deforms to the wavy shape of the
facings; by dimpling of the facings into the honeycomb cells;
or by bending of the sandwich, resulting in crimping near the
ends as a result of shear failure of the core or failure in the
facing-to-core bond.
3.3 This test method provides a standard method of obtain-
ing sandwich edgewise compressive strengths for panel design
and research and development.
4. Apparatus
4.1 Testing machine, capable of maintaining a controlled
loading rate and indicating the load with an accuracy of61 %
of the indicated value. The accuracy of the test machine shall
be verified in accordance with Practices E 4.
4.2 Spherical bearing block, preferably of the suspended,
self-aligning type.
4.3 Strain gage, capable of measuring strain to at least 0.001
mm/mm (0.0001 in./in.) and having a gage length not greater
than two thirds of the unsupported length of the specimens to
be tested.
4.4 Micrometer, gage, or caliper, capable of measuring
accurately to 0.025 mm (0.001 in.).
5. Test Specimens
5.1 The test specimens shall be rectangular in cross section.
The width of the specimens shall be at least 50 mm (2 in.) but
not less than twice the total thickness nor less than four
complete honeycomb cells. The unsupported length (dimen-
sion parallel to direction of applied load) shall be not greater
than eight times the total thickness.
5.2 Take care in preparing the test specimens to ensure
smooth end surfaces free of burrs. The ends shall be parallel to
each other and at right angles to the length of the specimens.
Good flat ends are essential for preventing localized end
failures. The loaded ends may be potted with resin and then
milled or ground flat.
6. Conditioning
6.1 When the physical properties of the component materi-
als are affected by moisture, bring the test specimens to
constant weight (61 %) before testing, preferably in a condi-
tioning room having temperature and humidity control, and
make the tests, preferably, in a room under the same condi-
tions. A temperature of 236 3°C (73 6 5°F) and a relative
humidity of 50 6 5 % are recommended as standard control
conditions.
7. Procedure
7.1 The length and width dimensions of the specimen shall
be measured to the nearest 0.25 mm (0.001 in.). Measure each
facing thickness to the nearest 0.025 mm (0.001 in.).
7.2 Test specimens shall be laterally supported adjacent to
the loaded ends on the facings of the sandwich to prevent early
bucking failure as a result of separation of the facings from the
core at the point of contact with the loading plates. This may be
done (1) by using clamps made of rectangular steel bars
1 This test method is under the jurisdiction of ASTM Committee D-30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved Oct. 10, 1999. Published February 2000. Originally
published as C 364 – 55T. Last previous edition C 364 – 94.
2 Annual Book of ASTM Standards, Vol 03.01.
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
fastened together so as to clamp the specimen lightly between
them (the cross-sectional dimensions of each of these bars shall
be not less than 6 mm (0.25 in.)) or (2) by fitting the specimen
snugly in round steel bars slotted axially to their diameter,
where such bars shall have a diameter not less than the
thickness of the sandwich plus 6 mm (0.25 in.). End support
may also be obtained by casting the ends of the specimens in
resin or other suitable molding material. The cast ends of the
specimen should be ground flush with the facings.
7.3 Apply the load through apparatus designed to distribute
the load properly to each facing and uniformly in each facing.
A suitable apparatus is shown in Fig. 1. The load may be
considered to be distributed properly if the strains measured on
each facing are within 5 % of each other in the early stages of
loading. It is essential that strains be measured in the early
stages to avoid widely varying results caused by different
eccentricities which occur if strains are not properly balanced.
7.4 Apply the load through constant rate of movement of the
movable head of the testing machine (Note 1) such that the
maximum load will occur between 3 and 6 min.
NOTE 1—A suggested rate of cross-head movement is 0.50 mm/min
(0.020 in./min).
8. Calculation
8.1 Calculate the facing compressive stress as follows:
s 5
P
A (1)
where:
s 5 facing compressive stress, MPa (psi);
P 5 ultimate load, N (lb); and
A 5 area of both facings,mm2 (in.2).
9. Report
9.1 The report shall include the following:
9.1.1 Description of test specimens; facings, core, adhesive,
9.1.2 Dimensions of test specimens, core orientation,
9.1.3 Type of end support, flatness of specimens,
9.1.4 Specimens conditioning, if any,
9.1.5 Test temperature and specimens time at temperature,
9.1.6 Test machine cross-head loading rate,
9.1.7 Maximum load and maximum stress in facings; indi-
vidual and average values, and
9.1.8 Description of failure mode; whether the facing
wrinkled, dimpled, or crimped; whether the specimen was bent
before failure occurred; and whether the core-to-facing bond
failed.
10. Precision and Bias
10.1 Precision—It is not possible to specify the precision of
the procedure in Test Method C 364 for measuring the facing
stress of the sandwich panel because of the unvailability of
consistent samples for testing.
10.2 Bias—Since there is no accepted reference material
suitable for determining the bias for the procedure in this test
method, bias has not been determined.
11. Keywords
11.1 edgewise; facing compressive stress; sandwich; sand-
wich construction
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at
610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org).
FIG. 1 Edgewise Compression Test Setup
C 364
2
Designation: C 365 – 00
Standard Test Method for
Flatwise Compressive Properties of Sandwich Cores 1
This standard is issued under the fixed designation C 365; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method covers the determination of the com-
pressive strength and modulus of sandwich cores. These
properties are usually determined for design purposes in a
direction normal to the plane of facings as the core would be
placed in a structural sandwich construction. The test proce-
dures pertain to compression in this direction in particular, but
also can be applied with possible minor variations to determin-
ing compressive properties in other directions.
1.2 The values stated in SI units are to be regarded as the
standard. The inch-pound units given may be approximate.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
E 4 Practices for Force Verification of Testing Machines2
3. Significance and Use
3.1 The flatwise compressive strength and modulus are
fundamental mechanical properties of sandwich cores that are
used in designing sandwich panels. Deformation data can be
obtained, and from a complete load-deformation curve it is
possible to compute the compressive stress at any load (such as
compressive stress at proportional limit load or compressive
strength at maximum load) and to compute the effective
modulus of the core.
3.2 This test method provides a standard method of obtain-
ing the flatwise compressive strength and modulus for sand-
wich panel design and research and development.
4. Apparatus
4.1 Testing Machine, capable of maintaining a controlled
loading rate and indicating the load with an accuracy of61 %
of the indicated value. The accuracy of the test machine shall
be verified in accordance with Practices E 4.
4.2 Spherical Bearing Block, preferably of the suspended,
self-aligning type.
4.3 Deflectometer or Compressometer, capable of measur-
ing the displacement with a precision of at least61 %. Bonded
resistance strain gages are not usually considered satisfactory
because of their stiffness. The reinforcing effect of bonding
these gages to some cores leads to large errors in measurement
of strains. Also, using the test machines cross-head travel
reading is not satisfactory as large modulus errors can result. A
transducer and rod setup as shown in Fig. 1 and Fig. 2 have
been found to work satisfactorily. Here a small hole is drilled
in the center of the specimen and in the bottom loading platen,
and a transducer rod is inserted that contacts the upper loading
platen.
4.4 Micrometer, Gage, or Caliper, capable of measuring
accurately to 0.025 mm (0.001 in.).
5. Test Specimens
5.1 Test specimens shall be of core or of sandwich construc-
tion and shall be of square or circular cross section having
areas not exceeding 400 mm2 (16 in.2), but not less than the
following minimum areas for various types of cores:
5.1.1 For continuous cores, such as balsa wood and foams,
the minimum cross-sectional area shall be 625 mm2 (1 in.2).
5.1.2 For open-celled cores, such as honeycomb, having
cells less than 6 mm (1⁄2 in.) the minimum cross-sectional area
shall be 2580 mm2 (4 in.2) and for cells 6 mm (1⁄2 in.) or greater
the minimum cross-sectional area shall be 5800 mm2 (9 in.2).
5.2 The height of the specimen shall be as agreed upon by
the purchaser and the seller.
5.3 The number of test specimens and the method of their
selection depend on the purpose of the particular test under
consideration, and no general rule can be given to cover all
cases. However, when specimens are to be used for acceptance
tests, not less than five specimens of a type shall be tested.
5.4 Prepare the test specimens so that the loaded ends will
be parallel to each other and perpendicular to the sides of the
specimen. To avoid local crushing at the ends of some
honeycomb cores, it is desirable to reinforce the ends with a
suitable material. The ends may be dipped in a thin layer of
resin or thin facings bonded to the core. When either of these
methods are used the test is called a stabilized compression
test. When the honeycomb cell edges are not stabilized, the test
1 This specification is under the jurisdiction of ASTM Committee D-30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved March 10, 2000. Published April 2000. Originally
published as C 365 – 55T. Last previous edition C 365 – 94.
2 Annual Book of ASTM Standards, Vol 03.01.
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued. 
Contact ASTM International (www.astm.org) for the latest information. 
is called a bare compression test.
6. Conditioning
6.1 When the physical properties of the core material areaffected by moisture, bring the specimens to constant weight
(61 %) before testing, preferably in a conditioning room
having temperature and humidity control, and make the tests,
preferably, in a room under the same conditions. A temperature
of 23 6 3°C (736 5°F) and a relative humidity of 506 5 %
are recommended for standard control conditions.
7. Procedure
7.1 The length and width dimensions of the specimen shall
be measured to the nearest 0.25 mm (0.01 in.) and the thickness
dimension to the nearest 0.025 mm (0.001 in.). Weigh the
specimen to the nearest 0.1 g and calculate the specimen
density.
7.2 Apply the load to the specimen through a spherical
loading block, preferably of the suspended, self-aligning type,
in such a manner that the block distributes the load as
uniformly as possible over the entire loading surface of the
specimen (Note 1). Apply the load at a constant rate of
movement of the cross-head of the testing machine (Note 2)
and at such a rate that the maximum load (Note 3) will occur
between 3 and 6 min.
7.3 Load-deflection curves may be taken to determine the
modulus of elasticity, proportional limit, and maximum load as
defined by the load at 2 % strain (see Note 3).
NOTE 1—Great care must be taken to load the specimen ends uniformly
and parallel to the load surfaces. At failure, the result of nonuniform
loading can usually be seen as a failure that is confined to one corner or
one edge of the specimen.
NOTE 2—A suggested rate of cross-head movement is 0.50 mm/min
(0.020 in./min).
NOTE 3—For cores that continue to compress and have no definite
maximum load, the maximum load shall be the load at 2 % strain.
8. Calculation
8.1 Calculate the flatwise compressive strength as follows:
s 5
P
A (1)
where:
s 5 core compressive strength, MPa (psi);
P 5 ultimate load, N (lb); and
A 5 cross-sectional area, mm2(in.2).
8.2 Calculate the flatwise compressive modulus as follows:
E 5
St
A (2)
where:
E 5 core compressive modulus, MPa (psi);
S 5 (DP/Du) slope of initial linear portion of load-
deflection curve, N/mm (lb/in.);
u 5 displacement of the loading block; and
t 5 core thickness, mm (in.).
9. Report
9.1 The report shall include the following:
FIG. 1 Transducer and Rod Setup FIG. 2 Close-up of Specimen
C 365
2
NOTICE: This standard has either been superceded and replaced by a new version or discontinued. 
Contact ASTM International (www.astm.org) for the latest information. 
9.1.1 Description of test specimens; core materials, facings
if used,
9.1.2 Dimensions and densities of the test specimens,
9.1.3 Method of bonding facings to specimens; adhesive,
cure cycle, and pressure,
9.1.4 Specimens conditioning, if any,
9.1.5 Test temperature and specimens time at temperature,
9.1.6 Test machine cross-head loading rate,
9.1.7 Compressive strength; individual values and average,
9.1.8 Compressive modulus; individual values and average,
if required,
9.1.9 Load-deflection curves, if required, and
9.1.10 Description of failure mode.
10. Precision and Bias
10.1 Precision—The data required for the development of a
precision statement is not available for this test method.
10.2 Bias—Since there is no accepted reference material
suitable for determining the bias for the procedure in this test
method, bias has not been determined.
11. Keywords
11.1 compressive modulus; compressive strength; flatwise;
sandwich core
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at
610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org).
C 365
3
NOTICE: This standard has either been superceded and replaced by a new version or discontinued. 
Contact ASTM International (www.astm.org) for the latest information. 
Designation: C 365 – 003
Standard Test Method for
Flatwise Compressive Properties of Sandwich Cores 1
This standard is issued under the fixed designation C 365; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method covers the determination of the compressive strength and modulus of sandwich cores. These properties are
usually determined for design purposes in a direction normal to the plane of facings as the core would be placed in a structural
sandwich construction. The test procedures pertain to compression in this direction in particular, but also can be applied with
possible minor variations to determining compressive properties in other directions.
1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given may be approximate.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
1 This specification is under the jurisdiction of ASTM Committee D-30 on Composite Materials and is the direct responsibility of Subcommittee D30.09 onSandwich
Construction.
Current edition approved March 10, 2000. Dec. 1, 2003. Published April 2000. December 2003. Originally published as C 365 – 55T. approved in 1955. Lastprevious
edition approved in 2000 as C 365 – 9400.
1
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. Inall cases only the current version
of the standard as published by ASTM is to be considered the official document.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
2. Referenced Documents
2.1 ASTM Standards:2
E 4 Practices for Force Verification of Testing Machines
3. Significance and Use
3.1 The flatwise compressive strength and modulus are fundamental mechanical properties of sandwich cores that are used in
designing sandwich panels. Deformation data can be obtained, and from a complete load-deformation curve it is possible to
compute the compressive stress at any load (such as compressive stress at proportional limit load or compressive strength at
maximum load) and to compute the effective modulus of the core.
3.2 This test method provides a standard method of obtaining the flatwise compressive strength and modulus for sandwich panel
design and research and development.
4. Apparatus
4.1 TestingMachine, capable of maintaining a controlled loading rate and indicating the load with an accuracy of61 % of the
indicated value. The accuracy of the test machine shall be verified in accordance with Practices E 4.
4.2 Spherical Bearing Block, preferably of the suspended, self-aligning type.
4.3 Deflectometer or Compressometer, capable of measuring the displacement with a precision of at least61 %. Bonded
resistance strain gages are not usually considered satisfactory because of their stiffness. The reinforcing effect of bonding these
gages to some cores leads to large errors in measurement of strains. Also, using the test machines cross-head travel reading is not
satisfactory as large modulus errors can result. A transducer and rod setup as shown in Fig. 1 and Fig. 2 have been found to work
satisfactorily. Here a small hole is drilled in the center of the specimen and in the bottom loading platen, and a transducer rod is
inserted that contacts the upper loading platen.
4.4 Micrometer, Gage, or Caliper, capable of measuring accurately to 0.025 mm (0.001 in.).
5. Test Specimens
5.1 Test specimens shall be of core or of sandwich construction and shall be of square or circular cross section having areas
2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. ForAnnual Book of ASTM Standards,
Vol 03.01. volume information, refer to the standard’s Document Summary page on the ASTM website.
FIG. 1 Transducer and Rod Setup
C 365 – 003
2
not exceeding 400 10 000 mm2 (16 in.2), but not less than the following minimum areas for various types of cores:
5.1.1 For continuous cores, such as balsa wood and foams, the minimum cross-sectional area shall be 625 mm2 (1 in. 2).
5.1.2 For open-celled cores, such as honeycomb, having cells less than 6 mm (1⁄4 in.) the minimum cross-sectional area shall
be 25800 mm2 (4 in. 2) and for cells 6 mm (1⁄4 in.) or greater the minimum cross-sectional area shall be 5800 mm2 (9 in.2).
5.2 The height of the specimen shall be as agreed upon by the purchaser and the seller.
5.3 The number of test specimens and the method of their selection depend on the purpose of the particular test under
consideration, and no general rule can be given to cover all cases. However, when specimens are to be used for acceptance tests,
not less than five specimens of a type shall be tested.
5.4 Prepare the test specimens so that the loaded ends will be parallel to each other and perpendicular to the sides of the
specimen. To avoid local crushing at the ends of some honeycomb cores, it is desirable to reinforce the ends with a suitable
material. The ends may be dipped in a thin layer of resin or thin facings bonded to the core. When either of these methods are used
the test is called a stabilized compression test. When the honeycomb cell edges are not stabilized, the test is called a bare
compression test.
6. Conditioning
6.1 When the physical properties of the core material are affected by moisture, bring the specimens to constant weight (61 %)
before testing, preferably in a conditioning room having temperature and humidity control, and make the tests, preferably, in a
room under the same conditions. A temperature of 236 3°C (736 5°F) and a relative humidity of 506 5 % are recommended
for standard control conditions.
7. Procedure
7.1 The length and width dimensions of the specimen shall be measured to the nearest 0.25 mm (0.01 in.) and the thickness
dimension to the nearest 0.025 mm (0.001 in.). Weigh the specimen to the nearest 0.1 g and calculate the specimen density.
7.2 Apply the load to the specimen through a spherical loading block, preferably of the suspended, self-aligning type, in such
a manner that the block distributes the load as uniformly as possible over the entire loading surface of the specimen (Note 1). Apply
the load at a constant rate of movement of the cross-head of the testing machine (Note 2) and at such a rate that the maximum
load (Note 3) will occur between 3 and 6 min.
7.3 Load-deflection curves may be taken to determine the modulus of elasticity, proportional limit, and maximum load as
defined by the load at 2 % strain (see Note 3).
FIG. 2 Close-up of Specimen
C 365 – 003
3
NOTE 1—Great care must be taken to load the specimen ends uniformly and parallel to the load surfaces. At failure, the result of nonuniform loading
can usually be seen as a failure that is confined to one corner or one edge of the specimen.
NOTE 2—A suggested rate of cross-head movement is 0.50 mm/min (0.020 in./min).
NOTE 3—For cores that continue to compress and have no definite maximum load, the maximum load shall be the load at 2 % strain.
8. Calculation
8.1 Calculate the flatwise compressive strength as follows:
s 5
P
A (1)
where:
s = core compressive strength, MPa (psi);
P = ultimate load, N (lb); and
A = cross-sectional area, mm2(in.2).
8.2 Calculate the flatwise compressive modulus as follows:
E 5
St
A (2)
where:
E = core compressive modulus, MPa (psi);
S = (DP/Du) slope of initial linear portion of load-deflection curve, N/mm (lb/in.);
u = displacement of the loading block; and
t = core thickness, mm (in.).
9. Report
9.1 The report shall include the following:
9.1.1 Description of test specimens; core materials, facings if used,
9.1.2 Dimensions and densities of the test specimens,
9.1.3 Method of bonding facings to specimens; adhesive, cure cycle, and pressure,
9.1.4 Specimens conditioning, if any,
9.1.5 Test temperature and specimens time at temperature,
9.1.6 Test machine cross-head loading rate,
9.1.7 Compressive strength; individual values and average,
9.1.8 Compressive modulus; individual values and average, if required,
9.1.9 Load-deflection curves, if required, and
9.1.10 Description of failure mode.
10. Precision and Bias
10.1 Precision—The data required for the development of a precision statement is not available for this test method.
10.2 Bias—Since there is no accepted reference material suitable for determining the bias for the procedure in this test method,
bias has not been determined.
11. Keywords
11.1 compressive modulus; compressive strength; flatwise; sandwich core
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned
in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk
of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the
responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should
make your views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above
address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website
(www.astm.org).
C 365 – 003
4
Designation: C 365 – 03
Standard Test Method for
Flatwise Compressive Properties of Sandwich Cores 1
This standard is issued under the fixed designation C 365; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard hasbeen approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method covers the determination of the com-
pressive strength and modulus of sandwich cores. These
properties are usually determined for design purposes in a
direction normal to the plane of facings as the core would be
placed in a structural sandwich construction. The test proce-
dures pertain to compression in this direction in particular, but
also can be applied with possible minor variations to determin-
ing compressive properties in other directions.
1.2 The values stated in SI units are to be regarded as the
standard. The inch-pound units given may be approximate.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:2
E 4 Practices for Force Verification of Testing Machines
3. Significance and Use
3.1 The flatwise compressive strength and modulus are
fundamental mechanical properties of sandwich cores that are
used in designing sandwich panels. Deformation data can be
obtained, and from a complete load-deformation curve it is
possible to compute the compressive stress at any load (such as
compressive stress at proportional limit load or compressive
strength at maximum load) and to compute the effective
modulus of the core.
3.2 This test method provides a standard method of obtain-
ing the flatwise compressive strength and modulus for sand-
wich panel design and research and development.
4. Apparatus
4.1 Testing Machine, capable of maintaining a controlled
loading rate and indicating the load with an accuracy of61 %
of the indicated value. The accuracy of the test machine shall
be verified in accordance with Practices E 4.
4.2 Spherical Bearing Block, preferably of the suspended,
self-aligning type.
4.3 Deflectometer or Compressometer, capable of measur-
ing the displacement with a precision of at least61 %. Bonded
resistance strain gages are not usually considered satisfactory
because of their stiffness. The reinforcing effect of bonding
these gages to some cores leads to large errors in measurement
of strains. Also, using the test machines cross-head travel
reading is not satisfactory as large modulus errors can result. A
transducer and rod setup as shown in Fig. 1 and Fig. 2 have
been found to work satisfactorily. Here a small hole is drilled
in the center of the specimen and in the bottom loading platen,
and a transducer rod is inserted that contacts the upper loading
platen.
4.4 Micrometer, Gage, or Caliper, capable of measuring
accurately to 0.025 mm (0.001 in.).
5. Test Specimens
5.1 Test specimens shall be of core or of sandwich construc-
tion and shall be of square or circular cross section having
areas not exceeding 10 000 mm2 (16 in.2), but not less than the
following minimum areas for various types of cores:
5.1.1 For continuous cores, such as balsa wood and foams,
the minimum cross-sectional area shall be 625 mm2 (1 in.2).
5.1.2 For open-celled cores, such as honeycomb, having
cells less than 6 mm (1⁄4 in.) the minimum cross-sectional area
shall be 2500 mm2 (4 in.2) and for cells 6 mm (1⁄4 in.) or
greater the minimum cross-sectional area shall be 5800 mm2 (9
in.2).
5.2 The height of the specimen shall be as agreed upon by
the purchaser and the seller.
1 This specification is under the jurisdiction of ASTM Committee D30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved Dec. 1, 2003. Published December 2003. Originally
approved in 1955. Last previous edition approved in 2000 as C 365 – 00.
2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. ForAnnual Book of ASTM
Standardsvolume information, refer to the standard’s Document Summary page on
the ASTM website.
1
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
5.3 The number of test specimens and the method of their
selection depend on the purpose of the particular test under
consideration, and no general rule can be given to cover all
cases. However, when specimens are to be used for acceptance
tests, not less than five specimens of a type shall be tested.
5.4 Prepare the test specimens so that the loaded ends will
be parallel to each other and perpendicular to the sides of the
specimen. To avoid local crushing at the ends of some
honeycomb cores, it is desirable to reinforce the ends with a
suitable material. The ends may be dipped in a thin layer of
resin or thin facings bonded to the core. When either of these
methods are used the test is called a stabilized compression
test. When the honeycomb cell edges are not stabilized, the test
is called a bare compression test.
6. Conditioning
6.1 When the physical properties of the core material are
affected by moisture, bring the specimens to constant weight
(61 %) before testing, preferably in a conditioning room
having temperature and humidity control, and make the tests,
preferably, in a room under the same conditions. A temperature
of 23 6 3°C (736 5°F) and a relative humidity of 506 5 %
are recommended for standard control conditions.
7. Procedure
7.1 The length and width dimensions of the specimen shall
be measured to the nearest 0.25 mm (0.01 in.) and the thickness
dimension to the nearest 0.025 mm (0.001 in.). Weigh the
specimen to the nearest 0.1 g and calculate the specimen
density.
7.2 Apply the load to the specimen through a spherical
loading block, preferably of the suspended, self-aligning type,
in such a manner that the block distributes the load as
uniformly as possible over the entire loading surface of the
specimen (Note 1). Apply the load at a constant rate of
movement of the cross-head of the testing machine (Note 2)
and at such a rate that the maximum load (Note 3) will occur
between 3 and 6 min.
7.3 Load-deflection curves may be taken to determine the
modulus of elasticity, proportional limit, and maximum load as
defined by the load at 2 % strain (see Note 3).
NOTE 1—Great care must be taken to load the specimen ends uniformly
and parallel to the load surfaces. At failure, the result of nonuniform
loading can usually be seen as a failure that is confined to one corner or
one edge of the specimen.
NOTE 2—A suggested rate of cross-head movement is 0.50 mm/min
(0.020 in./min).
NOTE 3—For cores that continue to compress and have no definite
maximum load, the maximum load shall be the load at 2 % strain.
8. Calculation
8.1 Calculate the flatwise compressive strength as follows:
s 5
P
A (1)
where:
FIG. 1 Transducer and Rod Setup FIG. 2 Close-up of Specimen
C 365 – 03
2
s = core compressive strength, MPa (psi);
P = ultimate load, N (lb); and
A = cross-sectional area, mm2(in.2).
8.2 Calculate the flatwise compressive modulus as follows:
E 5
St
A (2)
where:
E = core compressive modulus, MPa (psi);
S = (DP/Du) slope of initial linear portion of load-
deflection curve, N/mm (lb/in.);
u = displacement of the loading block; and
t = core thickness, mm (in.).
9. Report
9.1 The report shall include the following:
9.1.1 Description of test specimens; core materials, facings
if used,
9.1.2 Dimensions and densities of the test specimens,
9.1.3 Method of bonding facings to specimens; adhesive,
cure cycle, and pressure,
9.1.4 Specimens conditioning, if any,
9.1.5 Test temperature and specimens time at temperature,
9.1.6 Test machine cross-head loading rate,
9.1.7 Compressive strength; individual values and average,
9.1.8 Compressive modulus; individual values and average,
if required,
9.1.9 Load-deflection curves, if required, and
9.1.10 Description of failure mode.
10. Precision and Bias
10.1 Precision—The data required for the development of a
precisionstatement is not available for this test method.
10.2 Bias—Since there is no accepted reference material
suitable for determining the bias for the procedure in this test
method, bias has not been determined.
11. Keywords
11.1 compressive modulus; compressive strength; flatwise;
sandwich core
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned
in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk
of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the
responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should
make your views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above
address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website
(www.astm.org).
C 365 – 03
3
Designation: C 366 – 99
Standard Test Methods for
Measurement of Thickness of Sandwich Cores 1
This standard is issued under the fixed designation C 366; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 These test methods cover plant manufacturing proce-
dures for measuring the thickness of flat sandwich cores. The
two test methods covered are the following:
1.1.1 Test Method A—Roller-Type Thickness Tester and
1.1.2 Test Method B—Disk-Type Thickness Tester.
1.2 The values stated in SI are to be regarded as the
standard. The inch-pound units given may be approximate.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Significance and Use
2.1 Normally a close tolerance is desirable for core thick-
ness so that sandwich panels may be manufactured with all the
sandwich components fitting properly and without crushing the
core.
2.2 These test methods are designed for measuring thick-
ness of core as it is produced and are not intended for use in
determining dimensions of core specimens for other tests.
2.3 These test methods provide standard methods of obtain-
ing the core thickness of flat sandwich core materials and
provide a basis for determining average thickness dimensions.
3. Apparatus
3.1 Test Method A—Roller-Type Thickness Tester:
3.1.1 Roller-Type Thickness Tester, consisting of a flat table
with a rigid yoke framework attached, as shown in Fig. 1. Two
rollers shall be mounted on this yoke, one fixed in position and
one movable in the vertical direction. The vertical movement
of the upper roller shall be translated to a dial gage, calibrated
in 0.01-mm (0.001-in.) increments, that registers the amount of
variation above or below a preset nominal dimension. The
lower roller shall be fixed in position so that it projects 6 mm
(0.25 in.) above the surface of the table. The upper roller shall
exert a force of 18 N (4 lb) on the core material.
3.2 Method B—Disk-Type Thickness Tester:
3.2.1 Disk-Type Thickness Tester, consisting of a flat table
with a rigid yoke framework attached, as shown in Fig. 2. A
25-mm (1-in.) diameter presser disk movable in a vertical
direction shall be mounted on the yoke. The vertical movement
of the disk shall be translated to a dial gage, calibrated in
0.01-mm (0.001-in.) increments, that registers the amount of
variation above or below a preset nominal dimension. The disk
shall exert a force of 24 N (5.5 lb) on the core material.
4. Test Specimens
4.1 The test specimen shall be flat but otherwise may be any
1 These test methods are under the jurisdiction of ASTM Committee D-30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved Oct. 10, 1999. Published February 2000. Originally
published as C 366 – 55T. Last previous edition C 366 – 57(1999).
FIG. 1 Roller-Type Thickness Tester
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
length, width, and thickness consistent with the limits of the
measuring apparatus.
5. Conditioning
5.1 When the physical dimensions of the core materials are
affected by moisture, bring the specimens to constant weight
(61 %) before measuring, preferably in a conditioning room
having temperature and humidity control, and perform the
measuring, preferable, in a room under the same condition. A
temperature of 236 3°C (736 5°F) and a relative humidity of
50 6 5 % are recommended.
5.1.1 When a conditioning room is not available, record the
actual temperature and humidity at the time of measurement.
6. Procedure
6.1 Method A—Roller-Type Thickness Tester:
6.1.1 Place a spacer bar of a thickness equal to the desired
nominal core thickness between the rollers and zero the dial
gage. Remove the spacer bar and insert the core material to be
measured. Move the core through the rollers back and forth and
observe the dial gage readings. Take care not to exert hand
pressure on the core slice near the rollers, as this will affect the
dial gage readings.
6.2 Method B—Disk-Type Thickness Tester
6.2.1 Place a spacer bar of a thickness equal to the desired
nominal core thickness beneath the disk and zero the dial gage.
Remove the spacer bar and insert the core material to be
measured. With the disk automatically reciprocating vertically,
move the core in a saw tooth pattern along the length of the
specimen and observe the dial gage readings. If the honeycomb
sample is excessively warped and the weight of the presser disk
is not sufficient to straighten it, use an additional adjustable
pressure ring concentric with the 25-mm (1-in.) diameter
presser foot to force the sample to lie flat on the metal base
plate. The outside diameter of this ring shall be 115 mm (4.5
in.).
7. Report
7.1 The shall include the following:
7.1.1 Complete description of the material and size of
specimens,
7.1.2 Type of thickness measuring apparatus used,
7.1.3 Nominal core thickness,
7.1.4 Prescribed or recommended tolerance, plus or minus,
and
7.1.5 Maximum variation of dial gage reading from zero
(nominal core thickness) plus and minus.
8. Precision and Bias
8.1 Precision— It is not possible to specify the precision of
the procedure in Test Method C 366 for measuring the core
thickness because of the unavailability of consistent samples
for testing.
8.2 Bias—Since there is no accepted reference material
suitable for determining the bias for the procedures in this test
method, bias has not been determined.
9. Keywords
9.1 core thickness; sandwich core
FIG. 2 Disk-Type Thickness Tester
C 366
2
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determinationof the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at
610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org).
C 366
3
Designation: C 393 – 00
Standard Test Method for
Flexural Properties of Sandwich Constructions 1
This standard is issued under the fixed designation C 393; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers determination of the properties
of flat sandwich constructions subjected to flatwise flexure in
such a manner that the applied moments produce curvature of
the sandwich facing planes.
1.2 The values stated in SI units are to be regarded as the
standard. The inch-pound units given may be approximate.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
C 273 Test Method for Shear Properties of Sandwich Core
Materials2
C 480 Test Method for Flexure Creep of Sandwich Con-
structions2
E 4 Practices for Force Verification of Testing Machines3
3. Significance and Use
3.1 Flexure tests on flat sandwich construction may be
conducted to determine the sandwich flexural stiffness, the core
shear strength and shear modulus, or the facings compressive
and tensile strengths. Tests to evaluate core shear strength may
also be used to evaluate core-to-facing bonds.
3.2 These test methods provide a standard method of
obtaining the sandwich panel flexural strengths and stiffness.
3.3 Core shear strength and shear modulus are best deter-
mined in accordance with Test Method C 273.
3.4 The sandwich stiffness and core shear modulus may be
determined by calculations involving measured deflections of
sandwich flexure specimens. Tests can be conducted on short
specimens and on long specimens or on one specimen loaded
in two ways, and the flexural stiffness and shear modulus can
be determined by simultaneous solution of the complete
deflection equations for each span or each loading. If the facing
modulus values are known, a short span beam can be tested and
the calculated bending deflection subtracted from the beam’s
total deflection. This gives the shear deflection from which the
core shear modulus can be determined (Notes 1-3).
NOTE 1—For cores with high shear modulus, the shear deflection will
be quite small and ordinary errors in deflection measurements will cause
considerable variations in the calculated shear modulus.
NOTE 2—Concentrated loads on beams with thin facings and low
density cores can produce results that are difficult to interpret, especially
close to the failure point. Wider load pads with rubber pads may assist in
distributing the loads.
NOTE 3—To insure that simple sandwich beam theory is valid, a good
rule of thumb for the four-point bending test is the span length divided by
the sandwich thickness should be greater than 20 (L/d > 20) with the ratio
of facing thickness to core thickness less than 0.1 (t/c < 0.1).
4. Apparatus
4.1 Testing Machine, capable of maintaining a controlled
loading rate and indicating the load with an accuracy of61 %
of the indicated value. The accuracy of the test machine shall
be verified in accordance with Practices E 4.
4.2 Loading Fixtures,
4.3 Transducer, Deflectometer, Dial Gage, capable of mea-
suring the displacement with a precision of at least61 %.
4.4 Micrometer, Gage, or Caliper, capable of measuring
accurately to 0.025 mm (0.001 in.).
5. Test Specimen
5.1 The test specimen shall be rectangular in cross section.
The depth of the specimen shall be equal to the thickness of the
sandwich construction, and the width shall be not less than
twice the total thickness, not less than three times the dimen-
sion of a core cell, nor greater than one half the span length.
The specimen length shall be equal to the span length plus 50
mm (2 in.) or plus one half the sandwich thickness whichever
is the greater.
5.2 To determine core shear strength, it is necessary to
design the test specimen so that the moments produced at core
failure do not stress the facings beyond the compressive or
tensile proportional limit stress of the facing material. This
requires thicker facings and shorter support spans. If the
facings are too thick, the shear load will be carried to a
1 This specification is under the jurisdiction of ASTM Committee D30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved Jan. 10, 2000. Published April 2000. Originally
published as C 393 – 57 T. Last previous edition C 393 –94.
2 Annual Book of ASTM Standards, Vol 15.03.
3 Annual Book of ASTM Standards, Vol 03.01.
1
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
considerable extent by the facings, thus leading to a high
apparent core shear strength as computed by the usual approxi-
mate methods.
5.3 Proper design of a test specimen for determining com-
pressive or tensile strength of the facings is obtained by a
reverse of considerations for determining core shear strength.
The facings are thinner and the span is lengthened so that
greater moments are produced at loads low enough so that the
allowable core shear stress will not be exceeded. Tensile
failures rarely occur unless the tensile facing is thinner or of
different material than the compression facing. Failure in the
compression facing may occur by actual crushing, yielding
causing unduly large deflection, wrinkling of the facing into
the core or the facing popping off the core, or the facing
dimpling into the honeycomb cells.
6. Conditioning
6.1 When the physical properties of the component materi-
als are affected by moisture, the test specimens shall be brought
to constant weight (61 %) before testing, preferably in a
conditioning room with temperature and humidity control. The
test, preferably, should be made in a room under the same
conditions. A temperature of 236 3°C (73 6 5°F) and a
relative humidity of 506 5 % are recommended for standard
control conditions.
7. Procedure
7.1 Arrange the loading fixtures as shown in the appropriate
Fig. 1 or Fig. 2. Apply the load to the specimen through steel
bars or knife edges with loading pads. If after a trial test, it is
found that local core crushing failure occurs under a load point,
it is permissible to place narrow plates under the steel pads to
prevent such failures. Rubber pads can also be used to
distribute the load.
7.1.1 Fig. 3, Fig. 4, and Fig. 5 show test fixtures that have
been found to be satisfactory (Note 4).
NOTE 4—Other loading configurations besides the quarter-and third-
point loading may be used, but must be specified in the report.
7.2 Measure the dimensions of the specimens and span
length in mm (in.) to a precision of60.5 %.
7.3 Apply the load at a constant rate that will cause the
maximum load to occur between 3 to 6 min. Record the
maximum load.
7.4 Load-deflection curves can be taken to determine the
sandwich stiffness and core shear modulus. A transducer,
deflectometer, or dial gage can be used to measure the midspan
deflection.
8. Calculation
8.1 Core Shear Stress (Single-Point Midspan Load)—
Calculate the core shear stress as follows:
t 5
P
~d 1 c!b
(1)
where:
t = core shear stress, MPa (psi);
P = load, N (lb);
d = sandwich thickness, mm (in.);
c = core thickness, mm (in.); and
b = sandwich width, mm (in.).
8.1.1 Obtain the ultimate shear strength using Eq 1 whereP
equals the maximum load; the shear yield strength whereP
equals the yield load for core materials that yield more than
2 % strain using the 2 % offset method for the yield strength.
8.2 Facing Bending Stress (Midspan Load)—Calculate the
facing bending stress as follows:FIG. 1 Single-Point Load
FIG. 2 Two-Point Load
FIG. 3 Short Beam—Two-Point Load (Third Point)
C 393
2
s 5
PL
2t~d 1 c!b
(2)
where:
s = facing bending stress, MPa (psi);
t = facing thickness, mm (in.); and
L = span length, mm (in.).
8.3 Sandwich Beam Deflection (Midspan Load)—Calculate
the midspan deflection as follows:
D 5
PL3
48D 1
PL
4 U
total bending shear (3)
where:
D = total beam midspan deflection, mm (in.);
G = core shear modulus, MPa (psi);
E = facing modulus, MPa (psi); and
D = panel bending stiffness, N-mm2 (lb-in.2).
D 5
E~d3 2 c3!b
12
same facings (4)
D 5
E1t1E2t2~d 1 c!
2b
4~E1t1 1 E2t2!
different facings (5)
U 5
G~d 1 c!2b
4 c (6)
U 5 panel shear rigidity, N~lb!
8.4 Core shear stress (two-point load; one-quarter or one-
third span)—calculate the core shear stress as follows:
t 5
P
~d 1 c!b
(7)
8.5 Facing bending stress (two-point load; one-quarter
span)—calculate the facing bending stress as follows:
s 5
PL
4t~d 1 c!b
(8)
8.6 Sandwich panel deflection (two-point load, one-quarter
span)—calculate the midspan deflection as follows:
D 5
11PL3
768D 1
PL
8 U
total bending shear (9)
8.7 Flexural Stiffness and Core Shear Modulus—If deflec-
tions of the same sandwich are determined under central load,
P on spanL1 and also under total loadP applied at quarter-span
L2, the flexural stiffnessD and core shear modulusG may be
determined from simultaneous solution of the deflection equa-
tions as follows:
D 5
P1L1
3@1 2 ~11L2
2/8L1
2!#
48D1@1 2 ~2P1L1D2/P2L2D1!#
(10)
G 5
P1 L1c@8 L1
2/11L2
2 2 1#
D1b~d 1 c!
2@~16P1 L1
3D2/11P2 L2
3D1! 2 1#
(11)
9. Report
9.1 The report shall include the following:
9.1.1 Description of the test specimens; core material,
facings, and adhesive,
9.1.2 Dimensions of the test specimens, core orientation,
9.1.3 Type of loading and span,
9.1.4 Specimens conditioning, if any,
9.1.5 Test temperature and specimens time at temperature,
9.1.6 Test machine cross-head loading rate,
9.1.7 Strengths and stiffness; individual and average values,
9.1.8 Load-deflection curves, if required,
9.1.9 Description of specimen failure mode; whether failure
occurred in facings, core or facing-to-core bond.
10. Precision and Bias
10.1 Precision—The precision of the procedure in Test
Method C 393 for measuring sandwich construction flexural
properties is not available.
10.2 Bias—Since there is no accepted reference material
suitable for determining the bias for the procedures in this test
method, bias has not been determined.
11. Keywords
11.1 bending stress; core modulus; core stress; facing modu-
lus; facing stress; flexural stiffness; sandwich construction;
sandwich deflection; shear stress
FIG. 4 Long Beam—Long Beam Single-Point Load (Midspan)
FIG. 5 Long Beam—Quarter-Point Loading
C 393
3
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned
in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk
of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the
responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should
make your views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above
address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website
(www.astm.org).
C 393
4
Designation: C 394 – 00
Standard Test Method for
Shear Fatigue of Sandwich Core Materials 1
This standard is issued under the fixed designation C 394; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers determination of the effect of
repeated shear loads on sandwich core materials.
1.2 The values stated in SI units are to be regarded as the
standard. The inch-pound units given may be approximate.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
C 273 Test Method for Shear Properties of Sandwich Core
Materials2
E 4 Practices for Force Verification of Testing Machines3
3. Significance and Use
3.1 Usually the most critical stress to which a sandwich
panel core is subjected is shear. The effect of repeated shear
stresses on the core material can be very important.
3.2 These test methods provide a standard method of
obtaining the sandwich core shear fatigue properties.
4. Apparatus
4.1 Fatigue Testing Machine, any standard constant load
fatigue testing machine capable of applying a direct stress to
the specimen and equipped with a counter. The load measuring
system used shall have an accuracy of61 % of the indicated
value. The accuracy of the test machine shall be verified in
accordance with Practices E 4.
4.2 Testing Machine, any standard universal testing machine
capable of operation at a constant rate of motion of the
cross-head. The load measuring system used shall have an
accuracy of61 % of the indicated value. The accuracy of the
test machine shall be verified in accordance with Practices E 4.
4.3 Test Fixtures, test fixtures similar to those described in
Test Method C 273.
4.4 Micrometer, Gage, or Caliper, capable of measuring
accurately to 0.025 mm (0.001 in.).
5. Test Specimens
5.1 The test specimens shall be similar to those described in
Test Method C 273, except that the core material shall be
bonded directly to the fixture plates. The dimensions of the
specimen shall be such that the line of load action passes
through the diagonally opposite corners of the core material.
5.2 The number of test specimens and the method of their
selection depend on the purpose of the particular test under
consideration. It is recommended that at least five specimensare used for static control tests, and three specimens for each
stress level to be tested. For establishment of an S-N curve of
stress versus number of cycles to failure, test at least three
stress levels.
6. Conditioning
6.1 When the physical properties of the component materi-
als are affected by moisture, bring the test specimens to
constant weight (61 %) before testing, preferably in a condi-
tioning room having temperature and humidity control. Con-
duct the tests under the same temperature and humidity
conditions. A temperature of 236 3°C (73 6 5°F) and a
relative humidity of 506 5 % are recommended as standard
conditions.
7. Procedure
7.1 The length and width dimensions of the specimen shall
be measured to the nearest 0.25 mm (0.01 in.) and the thickness
dimension to the nearest 0.025 mm (0.001 in.). Weight the
specimen to the nearest 0.1 g and calculate the specimen
density.
7.2 Before the fatigue tests, test a minimum of five control
specimens statically in a standard test machine in accordance
with Test Method C 273. Use the average of the five specimens
as the 100 % level for the fatigue tests.
7.3 The stress levels to be tested shall be agreed upon by the
purchaser and the seller, or other parties involved. The stress
level is defined as the maximum repeated stress to which the
specimen is subjected.
7.4 For standard tests, use a stress ratio of minimum to
maximum load of 0.10, unless agreed upon previously by the
parties involved. Apply the mean load (50 % of difference
between maximum and minimum) through the preloading
1 This specification is under the jurisdiction of ASTM Committee D-30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved Jan. 10, 2000. Published April 2000. Originally
published as C 394 – 57 T. Last previous edition C 394 – 94 .
2 Annual Book of ASTM Standards, Vol 15.03.
3 Annual Book of ASTM Standards, Vol 03.01.
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
mechanism and the dynamic load (the remaining 50 %)
through the dynamic loading mechanism.
7.5 After testing has begun, check the loading frequently
unless the test machine is equipped with automatic load
maintainers. Also check the specimen’s temperature to be sure
that the loading rate is not heating the specimen more than 3°C
(5°F).
7.6 Record the maximum load and number of cycles to
failure.
7.7 Specimens that have core-to-plate adhesive adhesion
bond failures or adhesive cohesive failures are not valid and
shall be retested.
8. Calculation
8.1 Calculate the core shear stress in accordance with Test
Method C 273.
t 5
P
Pb (1)
where:
t 5 core shear stress, MPa (psi);
P 5 load on specimen, N (lb);
L 5 length of specimen, mm (in.); and
b 5 width of specimen, mm (in.).
9. Report
9.1 The report shall include the following:
9.1.1 Description of test specimens; core material, adhesive,
9.1.2 Dimensions and densities of the test specimens, core
orientation,
9.1.3 Method of bonding specimens to plates; cure cycle
and pressure,
9.1.4 Description of test machines, including loading rate on
static control specimen and testing speed (number of cycles per
second) on fatigue test specimens and mode of testing (tensile
or compressive).
9.1.5 Testing conditions, including temperature and relative
humidity.
9.1.6 Maximum load and maximum stress obtained on static
control test, and a description of the type of failure.
9.1.7 Stress levels and stress ratio used in fatigue tests.
9.1.8 Number of cycles to failure. If test is stopped at a
specified number of cycles without failure occurring, it shall be
so noted.
9.1.9 A curve of maximum stress versus number of cycles to
failure (S-N curve) shall be plotted.
10. Precision and Bias
10.1 Precision—The precision of the procedure in Test
Method C 394 for measuring sandwich core material shear
fatigue is not available.
10.2 Bias—Since there is no accepted reference material
suitable for determining the bias for the procedure in this test
method, bias has not been determined.
11. Keywords
11.1 fatigue; sandwich core; shear strength; shear stress
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at
610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org).
C 394
2
Designation: C 480 – 99
Standard Test Method for
Flexure Creep of Sandwich Constructions 1
This standard is issued under the fixed designation C 480; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the determination of the creep
characteristics and creep rate of sandwich constructions loaded
in flexure, at any desired temperature.
1.2 The values stated in SI units are to be regarded as the
standard. The inch-pound units given may be approximate.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
C 393 Test Method for Flexural Properties of Flat Sandwich
Constructions2
3. Significance and Use
3.1 The determination of the creep rate provides informa-
tion on the behavior of sandwich constructions under constant
load. Creep is defined as deflection under constant load over a
period of time beyond the initial deformation as a result of the
application of the load. Deflection data obtained from this test
method can be plotted against time, and a creep rate deter-
mined. By using standard specimen constructions and constant
loading, the test method may also be used to evaluate creep
behavior of sandwich panel core-to-facing adhesives.
3.2 This test method provides a standard method of obtain-
ing flexure creep of sandwich constructions for quality control,
acceptance specification testing, and research and develop-
ment.
4. Apparatus
4.1 The apparatus for loading the specimen shall conform to
Test Method C 393 except that a constant load shall be applied
by means of weights and a lever system. Fig. 1 shows a lever
and weight-loading apparatus that has been found satisfactory.
4.2 Micrometer, gage, or caliper, capable of measuring
accurately to 0.025 mm (0.001 in.).
5. Test Specimens
5.1 The test specimen shall be of sandwich construction of
a size and proportions conforming to the flexure test specimen
described in Test Method C 393.
5.2 The number of test specimens and the method oftheir
selection depend on the purpose of the particular test under
consideration, and no general rule can be given to cover all
cases. However, when specimens are to be used for acceptance
tests, at least three specimens shall be tested.
6. Conditioning
6.1 When the test is performed at room temperature and the
physical properties of the component materials are affected by
moisture, bring the test specimens to constant weight (61 %)
before testing, preferably in a conditioning room with tempera-
ture and humidity control. The tests, preferably, should be
made in a room under the same conditions. A temperature of 23
6 3°C (73 6 5°F) and a relative humidity of 506 5 % are
recommended for standard control conditions.
7. Procedure
7.1 Measure the dimensions of the specimens in millimetres
(inches) to a precision of60.5 %.
7.2 The load applied to the specimen by the lever system
shown in Fig. 1 may be calculated as follows:
P 5
W M1 w B
A 1 p (1)
where:
P 5 load applied to specimen, N (lb);
W 5 weight (including tray mass), N (lb);
M 5 distance between pivot point and weight point, mm
(in.);
w 5 mass of lever arm, N (lb);
p 5 mass of loading plate and rod, N (lb);
1 This specification is under the jurisdiction of ASTM Committee D-30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved Oct. 10, 1999. Published February 2000. Originally
published as C 480 – 61T. Last previous edition C 480 – 62 (1999).
2 Annual Book of ASTM Standards, Vol 15.03.
FIG. 1 Creep Test Apparatus and Loading System
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
B 5 distance from pivot point to center of gravity of the
loading arm, mm (in.); and
A 5 distance between pivot point and load point, mm (in.).
7.3 Attach the weight tray to the lever arm and support it
temporarily so that no load is applied to the specimen. If the
test is to be conducted at an elevated temperature, place the
apparatus and specimen in the oven and bring the oven up to
the desired test temperature. Allow sufficient time for the oven
and specimen to stabilize at the test temperature. Remove the
temporary support and apply the load slowly.
7.4 Measure deflections to the nearest 0.025 mm (0.001 in.).
Read the initial deflection and record it. Take deflection
readings at sufficient time intervals (Note 1) to define com-
pletely a creep curve with deflection plotted as the ordinate and
time as the abscissa.
NOTE 1—A recommended procedure is to take readings at 10-min
intervals for the first hour, then at hourly intervals up to 7 h. After this,
readings may be taken at any desired interval, such as twice a day, until the
total test time has been reached or failure has occurred.
8. Calculations
8.1 Calculate the creep deflection rate in millimetres
(inches) per hour or millimetres (inches) per day for any
portion of the curve (beyond the initial deformation) by
obtaining the difference of the two deflections and dividing by
the period of time.
8.2 For comparison of materials, the creep deflection may
be expressed as a percentage of the initial deflection after a
period of time as follows:
Creep, % of original deflection5
D 2 d
d 3 100 (2)
where:
D 5 total deflection under constant load at time t, mm (in.)
and
d 5 initial static deflection under the same load and at the
same temperature, mm (in.).
9. Report
9.1 The report shall include the following:
9.1.1 Description of the test specimens; facings, core, and
core-to-facing adhesive,
9.1.2 Dimensions of the test specimens, core orientation,
9.1.3 Test conditions including apparatus, test temperature,
span, loads, and test time,
9.1.4 Bending stress in the facings and shear stress in the
core calculated for the applied load in accordance with Test
Method C 393,
9.1.5 Creep deflection curve, and
9.1.6 Type and location of failure, if any, such as excessive
creep in the adhesive, core shear, and so forth.
10. Precision and Bias
10.1 Precision— It is not possible to specify the precision of
the procedure in Test Method C 480 for measuring the sand-
wich panel creep deflection because of the unavailability of
consistent samples for testing.
10.2 Since there is no accepted reference material suitable
for determining the bias for the procedure in this test method,
bias has not been determined.
11. Keywords
11.1 creep; creep deflection; sandwich; sandwich construc-
tion
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at
610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org).
C 480
2
Designation: C 481 – 99
Standard Test Method for
Laboratory Aging of Sandwich Constructions 1
This standard is issued under the fixed designation C 481; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method covers the determination of the resis-
tance of sandwich panels to severe exposure conditions as
measured by the change in selected properties of the material
after exposure. The exposure cycle to which the specimen is
subjected is an arbitrary test having no correlation with natural
weathering conditions.
1.2 The values stated in SI units are to be regarded as the
standard. The inch-pound units given may be approximate.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
C 273 Test Method for Shear Properties in Flatwise Plane of
Flat Sandwich Constructions or Sandwich Cores2
C 297 Test Method for Tensile Strength of Flat Sandwich
Constructions in Flatwise Plane2
C 363 Test Method for Delamination Strength of Honey-
comb Type Core Material2
C 364 Test Method for Edgewise Compressive Strength of
Flat Sandwich Constructions2
C 365 Test Methods for Flatwise Compressive Strength of
Sandwich Cores2
C 393 Test Method of Flexural Properties of Flat Sandwich
Constructions2
D 1781 Test Method for Climbing Drum Peel Test for
Adhesives3
3. Significance and Use
3.1 Most sandwich panels are subjected to various tempera-
ture and humidity environments. This laboratory aging test
determines the selected panel property degradation under
simulated conditions.
3.2 These test methods provide a standard method of
obtaining simulated environmentaldegradation data for quality
control, acceptance specification testing, and research and
development; however, these laboratory aging test procedures
do not have any correlation with natural weathering conditions.
4. Apparatus
4.1 Water tank, steam sprayer, oven, and freezer, all capable
of maintaining the required environment.
4.2 Test apparatus, shall conform to the appropriate ASTM
Test Method listed in Section 2.
5. Test Specimens
5.1 The test specimens shall conform to the appropriate
ASTM Test Method listed in Section 2.
6. Aging Test Procedures
6.1 Subject each specimen to six complete cycles of labo-
ratory aging, using either Cycle A (more severe) or Cycle B
(milder). The time interval between cycles shall not exceed 30
min.
6.2 Cycle A:
6.2.1 Totally immerse the specimen horizontally in water at
50 6 2°C (1206 3°F) for 1 h.
6.2.2 Spray with steam and water vapor at 956 3°C (2006
5°F) for 3 h.
6.2.3 Store at −126 3°C (106 5°F) for 20 h.
6.2.4 Heat at 1006 2°C (2106 3°F) in dry air for 3 h.
6.2.5 Spray again with steam and water vapor at 956 3°C
(200 6 5°F) for 3 h.
6.2.6 Heat in dry air at 1006 2°C (2106 3°F) for 18 h.
6.3 Cycle B:
6.3.1 Totally immerse the specimen horizontally in water at
50 6 3°C (1206 5°F) for 1 h.
6.3.2 Heat in dry air at 706 3°C (1606 5°F) for 3 h.
6.3.3 Spray with hot water at 706 3°F (1606 5°F) for 3 h.
6.3.4 Heat in dry air at 706 3°C (1606 5°F) for 18 h.
6.4 Test Conditions:
6.4.1 Steam shall be diffused so as to contact both faces and
all edges of panel.
6.4.2 The maximum relative humidity of the air shall be
1 This specification is under the jurisdiction of ASTM Committee D-30 on
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
Sandwich Construction.
Current edition approved Oct. 10, 1999. Published February 2000. Originally
published as C 481 – 61 T. Last previous edition C 481 – 62 (1999).
2 Annual Book of ASTM Standards, Vol 15.03.
3 Annual Book of ASTM Standards, Vol 15.06.
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
10 %; air shall be circulated by means of a fan to heat all
surfaces uniformly.
6.4.3 Water shall be sprayed so as to contact all panel
surfaces.
6.5 After completion of the six cycles of exposure, further
condition the specimen at a temperature of 236 3°C (73 6
5°F) and a relative humidity of 506 5 % and bring it back to
constant weight (61 %) before testing. Report the time re-
quired to attain constant weight.
7. Procedure
7.1 Make frequent inspections of the material during the
aging cycles for any signs of delamination or other disintegra-
tion. If there is any apparent damage to the material, describe
it in the report as well as the stage of the cycle in which the
damage became apparent.
7.2 Test specimens of the material is received and after
aging, in accordance with procedures selected from the follow-
ing:
Shear Test Test Method C 273
Compressive Strength Test Methods C 364 and C 365
Delamination Strength Test Method C 363
Tension Test Test Method C 297
Flatwise Flexure Test Test Method C 393
Climbing Drum Peel Test Method D 1781
8. Calculations
8.1 After the tests following the laboratory aging treatment
are completed, calculate the results as specified in the appro-
priate method and compare them with the corresponding values
obtained from the tests made on material as received.
8.2 Calculate the degradation percentages from Eq 1.
Degradation Percentage5
conditioned test value
as received test value3 100 (1)
9. Report
9.1 The report shall include the following:
9.1.1 Description of the test specimens as required by the
test method used,
9.1.2 Dimensions of the test specimens, core orientation,
9.1.3 Number of specimens tested,
9.1.4 The cycle (A or B) the specimens were subjected,
9.1.5 The “as received” test results,
9.1.6 The “conditioned” test results, and
9.1.7 The specimen degradation percentage; individual val-
ues and average.
10. Precision and Bias
10.1 Precision— It is not possible to specify the precision of
the procedure in Test Method C 481 for conducting sandwich
construction laboratory aging because of the unavailability of
consistent samples for testing.
10.2 Bias—Since there is no accepted reference material
suitable for determining the bias for the procedures in this test
method, bias has not been determined.
11. Keywords
11.1 aging; degradation; sandwich; sandwich construction
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at
610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org).
C 481
2
Designation: C 613/C 613M – 97
Standard Test Method for
Constituent Content of Composite Prepreg by Soxhlet
Extraction 1
This standard is issued under the fixed designation C 613/C 613M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method covers a Soxhlet extraction procedure
to determine the matrix content, reinforcement content, and
filler content of composite material prepreg. Volatiles content,
if appropriate, and required, is determined by means of Test
Method D 3530/D 3530M.
1.1.1 The reinforcement and filler must be substantially
insoluble in the selected extraction reagent and any filler must
be capable of being separated from the reinforcement by
filtering the extraction residue.
1.1.2 Reinforcement and filler content test results are total
reinforcement content and total filler content; hybrid material
systems with more than one type of either reinforcement or
filler cannot be distinguished.
1.2 This test method focuses on thermosetting matrix ma-
terial systems for which the matrix may be extracted by an
organic solvent. However, other, unspecified, reagents may be
used with this test method to extract other matrix material types
for the same purposes.
1.3 Alternate techniques for determining matrix and rein-
forcement content include Test Methods D 3171 (matrix diges-
tion), D 2584 (matrix burn-off/ignition), and D 3529 (matrix
dissolution). Test Method D 2584 is preferred for reinforce-
ment materials, such as glass, quartz, or silica, that are
unaffected by high-temperature environments.
1.4 The values stated in SI units are to be regarded as
standard.
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitationsprior to use.Specific precau-
tionary statements are given in Section 9 and Note 1 and Note
3.
2. Referenced Documents
2.1 ASTM Standards:
D 883 Terminology Relating to Plastics2
D 2584 Test Method for Ignition Loss of Cured Reinforced
Resins3
D 3171 Test Method for Fiber Content of Resin-Matrix
Composites by Matrix Digestion4
D 3529/D 3529M Test Method for Matrix Solids Content
and Matrix Content of Composite Prepreg4
D 3530/D 3530M Test Method for Volatiles Content of
Composite Material Prepreg4
D 3878 Terminology of High-Modulus Reinforcing Fibers
and Their Composites4
E 122 Practice for Choice of Sample Size to Estimate a
Measure of Quality for a Lot or Process5
E 177 Practice for Use of Terms Precision and Bias in
ASTM Test Methods5
E 456 Terminology Relating to Quality and Statistics5
E 1309 Guide for Identification of Composite Materials in
Computerized Material Property Databases4
E 1471 Guide for Identification of Fibers, Fillers, and Core
Materials in Computerized Material Property Databases4
2.2 NFPA Standard:
NFPA 86 Standard for Ovens and Furnaces6
3. Terminology
3.1 Definitions—Terminology D 3878 defines terms relating
to composite materials. Terminology D 883 defines terms
relating to plastics. Terminology E 456 and Practice E 177
define terms relating to statistics. In the event of a conflict
between terms, Terminology D 3878 shall have precedence
over the other documents.
3.1.1 matrix content, n—the amount of matrix present in a
composite or prepreg expressed either as percent by weight or
percent by volume. For polymer matrix composites this is resin
content. See Terminology D 3878.
3.1.2 prepreg, n—the admixture of fibrous reinforcement
and polymeric matrix used to fabricate composite materials. Its
form may be sheet, tape, or tow. For thermosetting matrices it
1 This test method is under the jurisdiction of ASTM Committee D-30 on High
Modulus Fibers and Their Composites and is the direct responsibility of Subcom-
mittee D30.03 on Constituent/Precursor Properties.
Current edition approved Sept. 10, 1997. Published May 1998. Originally
published as C 613 – 67. Last previous edition C 613 – 67(1990)e1.
2 Annual Book of ASTM Standards, Vol 08.01.
3 Annual Book of ASTM Standards, Vol 08.02.
4 Annual Book of ASTM Standards, Vol 15.03.
5 Annual Book of ASTM Standards, Vol 14.02.
6 Available from National Fire Protection Association Standards Council, 1
Batterymarch Park, PO Box 9101, Quincy, MA 02269-9101.
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued. 
Contact ASTM International (www.astm.org) for the latest information. 
has been partially cured to a controlled viscosity called “B
stage”. See Terminology D 3878.
3.1.3 resin content, n—see matrix content. See Terminology
D 3878.
3.1.4 sample, n—a small part or portion of a material or
product intended to be representative of the whole. See
Terminology D 883.
3.1.5 test result, n—the value obtained for a given property
from one test unit.7
3.1.5.1 Discussion—A test result may be a single observa-
tion or a combination of a number of observations when two or
more test specimens are measured for each test.
3.1.6 test specimen, n—a test unit or portion of a test unit
upon which a single or multiple observation is to be made.7
3.1.7 test unit, n—a unit or portion of a material that is
sufficient to obtain a test result(s) for the property or properties
to be measured.
3.1.7.1 Discussion—A test unit may be a subunit of a
primary (first stage) sampling unit or it may be a subunit of a
composite of primary sampling units or of increments from
these primary sampling units.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 dry resin content, n—prepreg resin content calculated
by subtracting the average mass loss due to volatiles from the
initial test specimen mass.
3.2.2 filler content, n—the amount of filler present in a
prepreg or composite expressed either as percent by weight or
percent by volume.
3.2.2.1 Discussion—In this test method the reinforcement is
separated from the remainder of the material, which includes
the matrix and the filler. If the filler is not then separated from
the matrix to determine the proportion of each, then the filler
content is included in the matrix content.
3.2.3 reinforcement content, n—the amount of reinforce-
ment present in a composite or prepreg expressed either as
percent by weight or percent by volume. This is sometimes
stated as a fraction, that is, reinforcement volume fraction.
3.2.4 replicate, n—a test specimen tested under nominally
identical conditions as other test specimens from the same
sample.
3.2.5 volatiles content, n—the amount of volatiles present in
a prepreg expressed as percent by weight.
3.2.6 wet resin content, n—prepreg resin content deter-
mined by considering volatiles as part of the resin mass.
3.3 Symbols:
3.3.1 A—initial mass of dry reinforcement during a reagent
exposure evaluation.
3.3.2 B—final mass of dry reinforcement during a reagent
exposure evaluation.
3.3.3 c—percent reinforcement mass change due to reagent
exposure.
3.3.4 CV—coefficient of variation statistic of a sample
population for a given property.
3.3.5 Ma—additional mass of filler in the test specimen.
3.3.6 Me—mass of the test specimen extraction residue.
3.3.7 Mi—initial mass of the test specimen.
3.3.8 Mr—mass of reinforcement in the test specimen.
3.3.9 n—number of replicates in the sample population.
3.3.10 sn−1—standard deviation statistic of a sample popu-
lation for a given property.
3.3.11 Wf—weight percent of filler in prepreg.
3.3.12 Wm—weight percent of matrix in prepreg.
3.3.13 Wr—weight percent of reinforcement in prepreg.
3.3.14 xi—test result for an individual test specimen from
the sample population for a given property.
3.3.15 x̄—average value of a sample population for a given
property.
4. Summary of Test Method
4.1 The exposed surface area of the prepreg material test
specimen is increased by cutting the test specimen into smaller
pieces. The test specimen is weighed and the matrix material
removed by means of Soxhlet extraction. The extracted residue
is dried and weighed. If a filler is present in the residue, in
addition to reinforcement, the two components are separated
by filtering the residue. From mass measurements of the initial
test specimen, and of the residue taken at various stages in the
process, the matrix content, reinforcement content, and filler
content are calculated and reported in weight percent.
4.1.1 Soxhlet Process—While described in detail in com-
mon quantitative chemical analysis textbooks, the Soxhlet
process is summarized as follows. The test specimen is loaded
into a filtering extraction thimble, which is placed into the
extraction chamber of a Soxhlet extraction assembly (see Fig.
1) containing an appropriate extraction reagent. The porous
thimble allows the liquid extraction reagent to pass while
retaining the test specimen. Freshly distilled liquid reagent
enters from the top of the extraction chamber, filling it until the
liquid reaches the highest level of the reagent-return tube. At
this moment the tube operates as a siphon, draining the
extraction chamber completely as it returns the liquid reagent
and any extracted material to a reservoir beneath the extraction
chamber. The heated reservoir boils the reagent, the vapor of
which is led to a condenser placed above the extraction
chamber. The distilled condensate then drips down into the
thimble, starting once again the process of filling the extraction
chamber. The Soxhlet operation is not a continuous operation,
but rather a sequence of fillings and siphonings, each cycle of
7 SeeForm and Style for ASTM Standards. FIG. 1 Schematic of Soxhlet Extraction Apparatus
C 613/C 613M
2
NOTICE: This standard has either been superceded and replaced by a new version or discontinued. 
Contact ASTM International (www.astm.org)for the latest information. 
which is called a reflux change. The heat input and reagent
volume are adjusted to cause the boiling reagent to return to the
extraction flask from the condenser at 3 to 10 reflux changes
per hour, with the extraction continuing for a minimum of 4 h
or 20 reflux changes, whichever comes first.
4.1.2 Volatiles Content—Volatiles content is primarily ap-
plicable to thermosetting materials, and, if required, is deter-
mined by Test Method D 3530/D 3530M. Volatiles content
determination requires different test specimens than those used
in the extraction process, since the process of determining
volatiles content renders thermosetting material specimens
unsuitable for subsequent organic solvent extraction.
5. Significance and Use
5.1 The prepreg volatiles content, matrix content, reinforce-
ment content, and filler content of composite prepreg materials
are used to control material manufacture and subsequent
fabrication processes, and are key parameters in the specifica-
tion and production of such materials, as well as in the
fabrication of products made with such materials.
5.2 The extraction products resulting from this test method
(the extract, the residue, or both) can be analyzed to assess
chemical composition and degree of purity.
6. Interferences
6.1 Extent of Cure in Thermosetting Systems—The effi-
ciency of extraction for thermosetting matrix materials is
directly related to the extent of cure of the resin system. Resins
that have started to cross-link (such as B-staged resins) will be
increasingly more difficult to extract as the cure advances. This
test method may not be appropriate for such materials; Test
Methods D 3171 or D 2585 may be better test method choices.
6.2 Reagent Selection—The proper reagent, in a suitable
quantity, must be selected for the constituents under test. The
reagents listed in Section 8 are provided for consideration,
particularly with regard to thermosetting materials, but cannot
be assured to perform well on all material systems within the
scope of this test method.
6.3 Thimble Contamination—If the extract is to undergo
further analysis, the thimble must be clean to avoid a signifi-
cant source of contamination.
6.4 Reinforcement Mass Change As a Result of Reagent—
The calculations of this test method assume that the reinforce-
ment mass (or filler, if filler content is being determined) is not
significantly affected (whether mass increase or mass loss) by
exposure to the reagent. Small, consistent, changes in the
reinforcement mass caused by exposure to the reagent can be
corrected by the process described in 14.4.5. The resulting
correction may be used if this change is sufficiently reproduc-
ible under the conditions of the test, and if this change has the
same value for the reinforcement alone as for the reinforcement
in the matrix. Otherwise, a different reagent, or another test
method, must be selected.
7. Apparatus
7.1 General Requirements:
7.1.1 Container Volume—A suggested volume is shown for
each container. However, other sizes may be required depend-
ing upon the test specimen size, the amount of reagent needed
to complete the extraction process, and the relative sizes of
related equipment.
7.1.2 Thermal Shock—Laboratory equipment that is sub-
jected to non-ambient temperatures (hot or cold) shall be of
tempered-glass or PTFE materials.
7.1.3 Post-Test Elemental Analysis—If a post-test elemental
analysis of the extract or residue is to be performed, laboratory
equipment contacting the test specimen shall be constructed of
PTFE and test specimen cutting shall be limited to tools that do
not leave an elemental trace.
7.2 General Equipment:
7.2.1 Analytical Balance—The analytical balance shall be
capable of reading to within60.1 mg.
7.2.2 Muffle Furnace—The muffle furnace used to condition
glass extraction thimbles shall be capable of maintaining a
temperature of 5106 15°C.
7.2.3 Air-Circulating Drying Oven—The drying oven shall
be capable of maintaining a temperature of 1636 3°C.
NOTE 1—Warning: For safety purposes listed in NFPA 86, take care to
limit volatile concentration in the oven by controlling sample quantity,
temperature, and ventilation.
7.2.4 Desiccator—The desiccator shall be capable of con-
taining the required test specimens.
7.3 Extraction Assembly:
7.3.1 Extraction Thimbles—The extraction thimbles shall
be deep, narrow filtering cups, of either borosilicate glass in an
appropriate pore size, or fat-extracted cellulose paper, suitable
for use in the extraction chamber.
7.3.2 Hot Plate—The hot plate shall have adjustable con-
trols suitable for heating the reagent within the reservoir flask
to 260°C and shall be capable of controlling the required
reagent temperature within615°C.
7.3.3 Reservoir Flask—The reservoir flask shall be of
borosilicate glass, of suitable volume (125 mL is suggested) for
the reagent quantity and extraction chamber volume, and shall
have a ground tapered joint capable of connection with the
remainder of the assembly.
7.3.4 Soxhlet Extraction Chamber—The extraction cham-
ber shall be of borosilicate glass, with an automatic recycling
siphon that recycles at a suitable liquid volume (50 mL is
suggested), and with a ground tapered joint at each end capable
of connecting with the remainder of the assembly.
7.3.5 Condensing Chamber—The condensing chamber
shall be of borosilicate glass, shall be water cooled, and shall
have a ground tapered joint capable of connecting with the
remainder of the assembly.
7.4 For Determining Filler Content:
7.4.1 Vacuum Filter System—The vacuum filter system
shall be suitable for filtering material from the filtering crucible
and holder.
7.4.2 Filtering Crucible—The filtering crucible shall be of
fritted glass and of suitable pore size and of appropriate volume
(30 mL is suggested).
NOTE 2—Filter porosity should be sized to filter the smallest expected
filler size from the reinforcement. If there is any doubt about the filter
pore-size selection, evaluate, with the material under test, filters of
successively different porosity size until confidence is established in the
filter size selected. While the glass fiber filter is used in concert with the
C 613/C 613M
3
NOTICE: This standard has either been superceded and replaced by a new version or discontinued. 
Contact ASTM International (www.astm.org) for the latest information. 
fritted filter to reduce any tendency to clog, note that certain materials,
particularly those containing filler of a broad range of particle size and
shape, may nevertheless clog the filter pores without visible sign. The
filter tare mass should be monitored for change as a result of the test. A
change in the filter tare mass indicates a potentially incorrect determina-
tion of reinforcement to filler proportion, and therefore, incorrect rein-
forcement and filler content test results.
7.4.3 Crucible Holder—The crucible holder shall be ca-
pable of holding the filtering crucible.
7.4.4 Glass Fiber Filter—A glass fiber filter of suitable
porosity and of appropriate diameter to fit in the filtering
crucible.8
7.5 Miscellaneous Common Laboratory Items—Other com-
monly available laboratory items may be needed including:
scissors or knife, beakers or flasks, flexible tubing, equipment
connectors, wash bottles, aluminum foil, and lint-free wipes.
8. Reagents and Materials
8.1 Purity of Reagents—As a minimum, a technical-grade
reagent is required to provide accurate results. However, when
resolving disputes or performing subsequent analysis of extract
or residue, a reagent-grade reagent shall be used. Unless
otherwise indicated, it is intended that the reagent conform to
the specifications of the Committee on Analytical Reagents of
the American Chemical Society, where such specifications are
available.9 Other equivalent grades may be used, provided the
reagent is of sufficiently high purity to permit its use without
lessening the accuracy of the determination.
8.2 Extraction Reagents—A suitable extractionreagent
shall be selected that is compatible with the material system
under test and the apparatus. Read and understand the procau-
tions listed in Section 9 before selecting an extraction reagent.
Extraction reagents that have been found effective for many
thermosetting matrices include the following:
8.2.1 Dimethylformamide (DMF), (CH5)2NCHO.
NOTE 3—Warning: As of the approval date of this standard, DMF was
listed by the International Agency for Research on Cancer in Group 2B as
a “possible human carcinogen” and is considered a reproductive toxin by
the National Toxicology Program. See a recent DMF material safety data
sheet for more information.
8.2.2 Ethanol (Ethyl Alcohol), C2H5OH.
8.3 Washing Reagents—A suitable washing reagent(s) shall
be selected that is compatible with the material system under
test and the apparatus. Read and understand the precautions
listed in Section 9 before selecting a washing reagent. Washing
reagents that have been found effective include the following:
8.3.1 Acetone (2-Propanone), CH8COCH8.
8.3.2 Water, Distilled or Demineralized.
9. Hazards
9.1 This test method should be used only by laboratory
workers with general training in the safe handling of chemi-
cals. A source of useful information is given in Footnote 10.10
NOTE 4—Precaution: In addition to other precautions, consult the
appropriate material safety data sheet for each material used, including
reagent materials and test specimen materials, for specific recommenda-
tions on safety and handling.
NOTE 5—Precaution: In addition to other precautions, the extraction
and filtering processes should be performed under a suitable vented
chemical fume hood.
NOTE 6—Precaution: In addition to other precautions, materials that
have been exposed to potentially toxic or flammable reagents must be
air-dried under a hood before being subsequently oven-dried, to eliminate
build-up of a potentially dangerous concentration of vapor in the drying
oven. Useful guidelines for estimating the safe volatiles mass for a given
oven size are given in NFPA Standard 86.
9.2 Use of mixed extraction reagents with different boiling
points are not covered by this test method.
NOTE 7—Precaution: In addition to other precautions, do not use
mixed extraction reagents with different boiling points. Use of mixed
extraction reagents with different boiling points can result in an explosion
if the low-boiling fraction siphons into the extraction chamber while the
high-boiling fraction is being heated; the low-boiling fraction may then
superheat and overpressure the apparatus.
10. Sampling, Test Specimens, and Test Units
10.1 Test Units—Unless otherwise specified, the test unit
shall consist of a single test specimen upon which a single
observation is to be made.
10.2 Sampling—Unless otherwise specified, at least three
test specimens (test units) per sample shall be evaluated. For
statistically significant data the procedures outlined in Practice
E 122 should be consulted. The method of sampling shall be
reported.
10.3 Test Specimen Geometry—The mass of each individual
test specimen shall be at least 1.0 g and, unless otherwise
specified, shall be 2.0 to 3.0 g.
10.4 Test Specimen Preparation:
10.4.1 Labeling—Label each test specimen container so
that they will be distinct from each other and traceable back to
the sampled material. Report the labeling scheme and method.
11. Preparation of Apparatus
11.1 Clean the extraction thimbles and filter crucibles. Dry
the filter crucibles (including the glass fiber filters) and
extraction thimbles in the drying oven (unless otherwise
specified, dry at 1636 3°C) until there is no perceptible mass
change with time. Remove from the oven and cool in the
desiccator. Determine and record, to within 0.1 mg, the initial
tare mass of each. The tare mass of the filter crucibles shall
include the installed glass-fiber filter.
11.2 After cleaning, drying, and taring, store all extraction
thimbles and filter crucibles in the desiccator until use.
12. Calibration and Standardization
12.1 All measuring equipment shall have certified calibra-
tions that are current at the time of use of the equipment. The
calibration documentation shall be available for inspection.
8 A Reeve Angle Grade 934 AH or equivalent is suggested.
9 Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
listed by the American Chemical Society, seeAnalar Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and theUnited States Pharmacopeia
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD.
10 Prudent Practices in the Laboratory: Handling and Disposal of Chemicals,
National Academy Press, 1995.
C 613/C 613M
4
NOTICE: This standard has either been superceded and replaced by a new version or discontinued. 
Contact ASTM International (www.astm.org) for the latest information. 
13. Conditioning
13.1 No preconditioning or conditioning of the test speci-
men is required.
13.2 Unless otherwise specified, conduct the tests at 236
3°C and 506 10 % relative humidity. Record and report the
actual laboratory environment.
14. Procedures
14.1 Selection of Test Parameters—Specify the following
test parameters, as applicable, prior to test.
14.1.1 Test Results—Specify the properties to be deter-
mined by this test method, including: volatiles content, matrix
content (dry, wet, or both), and reinforcement content. If no
properties are specified, determine and report only matrix
content (wet resin content) and reinforcement content, and
filler content if appropriate.
14.1.2 Reagent Selection—Specify the reagents (Section 8)
to be used for extraction and washing. If appropriate reagents
are not specified, or not known, contact the material manufac-
turer for guidance on reagent selection.
14.1.3 Sampling Method—Specify the material sampling
method, if sampling is to be conducted by the testing labora-
tory.
14.2 General Instructions:
14.2.1 Report any deviations from this test method, whether
intentional or inadvertent.
14.2.2 Shield the balance from air drafts and isolate it from
vibrations that could affect its accuracy.
14.2.3 Determine mass to the nearest 0.1 mg.
14.2.4 Process each test specimen separately.
NOTE 8—Reagent quantities and container volumes in this test method
are estimates based on common material systems and the standard test
specimen mass. Reagent quantities and equipment sizes may need to be
adjusted as a function of material system, coupon size, or both.
14.3 Volatiles Content—If volatiles content is to be deter-
mined, on the same number of additional and separate test
specimens, each sampled immediately adjacent to one of the
extraction test specimens, determine and report volatiles con-
tent in accordance with Test Method D 3530/D 3530M. If the
dry resin content is required, the average volatiles content from
these tests will be used to correct the extraction results.
NOTE 9—Volatiles content is conducted on separate test specimens
since the process of determining volatiles content tends to advance
thermosetting resins, making subsequent resin extraction by this test
method difficult or impossible.
14.4 Extraction:
14.4.1 Cutting—Cut the prepreg test specimen into small
pieces (nominally 10 to 15-mm squares), place the pieces into
a clean, dry, tared extraction thimble, and blend the pieces
thoroughly. Take care during cutting and blending to avoid
losing even small quantities of matrix or reinforcement.
14.4.2 Initial Mass—Weigh the test specimen and thimble,
subtract the tared mass of the thimble, and record this result as
Mi, the initial test specimen mass.
14.4.3 Refluxing:
14.4.3.1 Setup the extraction apparatus under a suitably
vented chemical fume hood.
14.4.3.2 Position the thimble within the extractor. Add
extraction reagent to the extraction tube sufficient to immerse
the test specimen and fill about2⁄3 of the thimble (typically 35
mL of reagent).14.4.3.3 Assemble the Soxhlet extractor to the reservoir
flask containing additional reagent (typically 55 mL of reagent,
for a total of about 90 mL of reagent in the assembly). Attach
the condenser to the top of the extractor, and provide supports
for the entire assembly as needed.
14.4.3.4 Turn on the condenser cooling water.
14.4.3.5 Set the hot plate temperature control to a tempera-
ture appropriate for the selected reagent and turn on the hot
plate. When condensation of the reagent occurs adjust the hot
plate temperature to effect 3 to 10 reflux changes per hour.
Continue to reflux for a minimum of 4 h or 20reflux changes,
whichever comes first.
NOTE 10—If the extractor volume is too large compared to the volume
of the liquid in the reservoir, with each cycle the siphoning liquid may
cool the reservoir below the reagent boiling point, and a stable process
may be difficult to obtain. A magnetically driven stirrer placed in the
reservoir may help.
NOTE 11—For high boiling reagents it may be necessary to wrap the
extraction chamber with aluminum foil to reduce heat loss.
14.4.3.6 When extraction is completed, turn off the hot plate
and allow the apparatus to cool until safe to handle. Remove
the extraction thimble from the extraction assembly, drain any
remaining reagent, and air-dry under a hood until any flam-
mable or toxic materials have evaporated. Complete the drying
to essentially constant mass in the forced-air drying oven at
1636 3°C. Examine the residue for signs of incomplete
extraction. If matrix material remains, repeat the extraction
until extraction is complete, either with the original reagent or
with an alternate reagent.
14.4.3.7 Weigh the test specimen and thimble. Subtract the
tare mass of the thimble from this result and record asMe, the
extracted test specimen residual reinforcement and filler mass.
14.4.4 Filler Content—If filler is known or suspected to
exist, or is visibly present in the extracted residue, filter the
extract to separate the filler from the reinforcement. Otherwise
record the residual massMe as the reinforcement mass,Mr.
14.4.4.1 Under a suitable vented chemical fume hood, wash
the extraction tube, reservoir flask, and extraction thimble
(including the extraction residue), using a wash bottle and
appropriate solvent wash, and saving all washings in a flask.
All visible filler must be washed from the apparatus in order for
filler content to be determined.
NOTE 12—If washing the extraction apparatus with solvent fails to
remove filler that is caked on the apparatus, the following procedure has
been used to remove carbonaceous filled phenolic resins. Similar proce-
dures may be developed for other material systems, if needed. Place the
air-dried apparatus in a muffle furnace at 4006 15°C for a minimum of
1 h. Cool in a desiccator and then weigh. If the apparatus was pretared,
subtract the tare mass from these results and record the total as additional
filler mass,Ma, to be added to the filler mass. If the apparatus was not
pretared, determine the tare masses by inserting the apparatus into the
muffle furnace at 5406 15°C for a minimum of 1 h; cool in a desiccator,
then weigh, recording these weighings as the tared masses.
14.4.4.2 Place a tared filter crucible in a vacuum filtration
system. Filter the washings with this system through the filter
crucible, washing the residue clean of filler with a suitable
C 613/C 613M
5
NOTICE: This standard has either been superceded and replaced by a new version or discontinued. 
Contact ASTM International (www.astm.org) for the latest information. 
solvent until only the reinforcement remains.
14.4.4.3 Air-dry the filter crucible under a chemical fume
hood, then complete the drying process in the drying oven at
163 6 3°C, for a minimum of 1 h or until an essentially
constant mass is achieved. Cool the filter crucible in a
desiccator and weigh. Subtract the crucible tare mass from the
result and record the resulting reinforcement mass asMr.
14.4.5 Correction for Reinforcement Mass Change—If the
reagent is known (or observed) to create a significant change (>
63 %), or inconsistent change, or both, in the mass of the
reinforcement material, then replace the reagent with another
that has little to no effect on the reinforcement. Correct small,
consistent reinforcement mass changes by the following pro-
cess.
NOTE 13—Certain reinforcements may, when exposed to ambient
humidity, contain adsorbed or absorbed water up to a few weight percent.
Steps should be taken during this evaluation to control this adsorbed or
absorbed moisture, so that an accurate assessment of reinforcement
change due to reagent exposure may be made.
14.4.5.1 Measure out dry (no sizing or finish) reinforcement
material equal to the mass of reinforcement in the nominal test
specimen. Record this value asA, the initial mass of the dry
reinforcement.
14.4.5.2 Duplicate the extraction procedure used on the
prepreg, with the dry reinforcement material, exposing the dry
reinforcement to the reagent for the same length of time that
the prepreg was exposed.
14.4.5.3 Weigh the exposed dry reinforcement in the
thimble. Subtract the tared mass of the thimble from this result
and record this value asB, the final mass of the exposed dry
reinforcement. A correction to the final results is made by
calculation in 15.1, based on any change in reinforcement mass
resulting from this exposure.
15. Calculation
15.1 Reinforcement Mass Change Due to Reagent
Exposure—Calculate the reinforcement mass change (loss or
gain) due to reagent exposure in accordance with Eq 1,
reporting the test result to the nearest 0.1 %.
c 5
A 2 B
A 3 100 (1)
where:
c 5 percent reinforcement mass change due to reagent
exposure, %,
A 5 initial mass of dry reinforcement, g, and
B 5 mass of dry reinforcement after exposure to reagent, g.
NOTE 14—A positive value forc indicates a mass loss due to reagent
exposure, while a negative value indicates a mass gain due to reagent
exposure.
Do not use the mass change,c, in subsequent calculations ifc is greater
than −0.5 % but less than +0.5 %.
15.2 Reinforcement Mass—Calculate the reinforcement
mass of the test specimen in accordance with Eq 2, reporting
the test result to the nearest 0.001 g.
Mro 5
100Mr
1002 c (2)
where:
Mro 5 original reinforcement mass, g, and
Mr 5 measured remainder of reinforcement, g.
15.3 Reinforcement Content—Calculate the reinforcement
content (weight percent) of the test specimen in accordance
with Eq 3, reporting the test result to the nearest 0.1 %.
Wr 5 1003
Mro
Mi
(3)
where:
Wr 5 weight percent reinforcement, %,
Mro 5 original mass of reinforcement, g, and
Mi 5 initial mass of test specimen, g.
15.4 Matrix Content—Calculate the matrix content (wet
resin content) (weight percent) of the test specimen in accor-
dance with Eq 4, reporting the test result to the nearest 0.1 %.
Wm 5 1002 SMeMi 3 100D (4)
where:
Wm 5 weight percent of matrix, %, and
Me 5 mass of extracted residue, g.
15.5 Dry Resin Content—Where appropriate and required,
calculate the dry resin content (weight percent) of the test
specimen in accordance with Eq 5, reporting the test result to
the nearest 0.1 %.
Wm ~dry! 5
1002 Wr 2 VC
1 2 VC/100 (5)
where:
Wm(dry) 5 weight percent of matrix, %, and
VC 5 average volatiles content (weight percent)
from 14.3, %.
15.6 Filler Content—Calculate the filler content (weight
percent) of the test specimen in accordance with Eq 6,
reporting the test result to the nearest 0.1 %.
Wf 5 1002 Wr 2 Wm 1
1003 Ma
Mi
(6)
where:
Wf 5 weight percent of filler, %, and
Ma 5 additional filler mass cleaned from equipment, g.
16. Report
16.1 Report the following information, or references point-
ing to other documentation containing this information, to the
maximum extent applicable. Guides E 1309 and E 1471 may
be helpful to those reporting material descriptions, constituent
descriptions, or both.
16.1.1 Reporting of items that are beyond the control of a
given testing laboratory, such as materialdetails, shall be the
responsibility of the requestor.
16.1.2 The revision level or date of issue of this test method.
16.1.3 Any variations to this test method, anomalies noticed
during testing, or equipment problems occurring during testing.
16.1.4 Identification of the material tested including: mate-
rial specification, material type, material designation, manufac-
turer, manufacturer’s lot or batch number, source (if not from
manufacturer), date of certification or prepregging, expiration
of certification, filament diameter, tow or yarn filament count
C 613/C 613M
6
NOTICE: This standard has either been superceded and replaced by a new version or discontinued. 
Contact ASTM International (www.astm.org) for the latest information. 
and twist, sizing, form or weave, reinforcement areal weight,
and matrix type.
16.1.5 Method of preparing the test specimen, including test
specimen labeling scheme and method, test specimen geom-
etry, sampling method, and specimen cutting method.
16.1.6 Calibration dates and methods for all measurement
and test equipment, or a suitable reference to the same.
16.1.7 The type of apparatus used and the nominal and
actual test temperatures.
16.1.8 Relative humidity and temperature of the testing
laboratory.
16.1.9 Number of test specimens tested.
16.1.10 The matrix content (wet, dry, or both) of the test
specimen by weight percent;
16.1.11 The reinforcement content of the test specimen by
weight percent;
16.1.12 The filler content of the test specimen by weight
percent;
16.1.13 The volatiles content of the prepreg by weight
percent;
16.1.14 The percent reinforcement mass change due to
exposure to the extraction reagent.
16.1.15 The average value( x̄) , standard deviation (sn−1),
and percent coefficient of variation (% CV) for the matrix
content, reinforcement content, filler content, and volatiles
content, for sample populations of three or more.
16.1.16 The date(s) and location(s) of the test(s); and
16.1.17 The name of the test operator(s).
17. Precision and Bias
17.1 Committee D-30 is currently planning a round-robin
test series for this test method for the purpose of defining the
precision. Bias cannot be determined for this test method as no
reference material exists.
18. Keywords
18.1 composite materials; filler content; matrix content;
prepreg; reinforcement content; resin content; resin matrix
content; volatiles content
APPENDIX
(Nonmandatory Information)
X1. TEST DATA REPORTING FORM (Fig. 2)
Composite Material Designation:
Reinforcement Designation:
Extraction Reagent:
FIG. X1.1 Example Test Data Reporting Form
C 613/C 613M
7
NOTICE: This standard has either been superceded and replaced by a new version or discontinued. 
Contact ASTM International (www.astm.org) for the latest information. 
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, 100 Barr Harbor Drive, West Conshohocken, PA 19428.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States. Individual
reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585
(phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (http://www.astm.org).
C 613/C 613M
8
NOTICE: This standard has either been superceded and replaced by a new version or discontinued. 
Contact ASTM International (www.astm.org) for the latest information. 
Designation: C 613/C 613M – 97 (Reapproved 2003) e1
Standard Test Method for
Constituent Content of Composite Prepreg by Soxhlet
Extraction 1
This standard is issued under the fixed designation C 613/C 613M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
e1 NOTE—Warning/precaution notes were moved into the text editorially in October 2003.
1. Scope
1.1 This test method covers a Soxhlet extraction procedure
to determine the matrix content, reinforcement content, and
filler content of composite material prepreg. Volatiles content,
if appropriate, and required, is determined by means of Test
Method D 3530/D 3530M.
1.1.1 The reinforcement and filler must be substantially
insoluble in the selected extraction reagent and any filler must
be capable of being separated from the reinforcement by
filtering the extraction residue.
1.1.2 Reinforcement and filler content test results are total
reinforcement content and total filler content; hybrid material
systems with more than one type of either reinforcement or
filler cannot be distinguished.
1.2 This test method focuses on thermosetting matrix ma-
terial systems for which the matrix may be extracted by an
organic solvent. However, other, unspecified, reagents may be
used with this test method to extract other matrix material types
for the same purposes.
1.3 Alternate techniques for determining matrix and rein-
forcement content include Test Methods D 3171 (matrix diges-
tion), D 2584 (matrix burn-off/ignition), and D 3529/D 3529M
(matrix dissolution). Test Method D 2584 is preferred for
reinforcement materials, such as glass, quartz, or silica, that are
unaffected by high-temperature environments.
1.4 The values stated in SI units are to be regarded as
standard.
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.Specific precau-
tionary statements are given in Section 9 and 7.2.3 and 8.2.1.
2. Referenced Documents
2.1 ASTM Standards:2
D 883 Terminology Relating to Plastics
D 2584 Test Method for Ignition Loss of Cured Reinforced
Resins
D 3171 Test Method for Constituent Content of Composite
Materials
D 3529/D 3529M Test Method for Matrix Solids Content
and Matrix Content of Composite Prepreg
D 3530/D 3530M Test Method for Volatiles Content of
Composite Material Prepreg
D 3878 Terminology of Composite Materials
E 122 Practice for Calculating Sample Size to Estimate,
With Specified Tolerable Error, the Average for Character-
istic of a Lot or Process
E 177 Practice for Use of Terms Precision and Bias in
ASTM Test Methods
E 456 Terminology Relating to Quality and Statistics
E 1309 Guide for Identification of Composite Materials in
Computerized Material Property Databases
E 1471 Guide for Identification of Fiber-Reinforced
Polymer-Matrix Composite Materials in Databases
2.2 NFPA Standard:
NFPA 86 Standard for Ovens and Furnaces3
3. Terminology
3.1 Definitions—Terminology D 3878 defines terms relating
to composite materials. Terminology D 883 defines terms
relating to plastics. Terminology E 456 and Practice E 177
define terms relating to statistics. In the event of a conflict
between terms, TerminologyD 3878 shall have precedence
over the other documents.
1 This test method is under the jurisdiction of ASTM Committee D30 on
Composite Materials and is the direct responsibility of Subcommittee D30.03 on
Constituent/Precursor Properties.
Current edition approved Oct. 1, 2003. Published October 2003. Originally
approved in 1967. Last previous edition approved in 1997 as C 613 – 97.
2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. ForAnnual Book of ASTM
Standardsvolume information, refer to the standard’s Document Summary page on
the ASTM website.
3 Available from National Fire Protection Association (NFPA), 1 Batterymarch
Park, Quincy, MA 02269-9101.
1
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
3.1.1 matrix content, n—the amount of matrix present in a
composite or prepreg expressed either as percent by weight or
percent by volume. For polymer matrix composites this is resin
content. D 3878
3.1.2 prepreg, n—the admixture of fibrous reinforcement
and polymeric matrix used to fabricate composite materials. Its
form may be sheet, tape, or tow. For thermosetting matrices it
has been partially cured to a controlled viscosity called “B
stage”. D 3878
3.1.3 resin content, n—see matrix content. D 3878
3.1.4 sample, n—a small part or portion of a material or
product intended to be representative of the whole.D 883
3.1.5 test result, n—the value obtained for a given property
from one test unit.4
3.1.5.1 Discussion—A test result may be a single observa-
tion or a combination of a number of observations when two or
more test specimens are measured for each test.
3.1.6 test specimen, n—a test unit or portion of a test unit
upon which a single or multiple observation is to be made.4
3.1.7 test unit, n—a unit or portion of a material that is
sufficient to obtain a test result(s) for the property or properties
to be measured.
3.1.7.1 Discussion—A test unit may be a subunit of a
primary (first stage) sampling unit or it may be a subunit of a
composite of primary sampling units or of increments from
these primary sampling units.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 dry resin content, n—prepreg resin content calculated
by subtracting the average mass loss due to volatiles from the
initial test specimen mass.
3.2.2 filler content, n—the amount of filler present in a
prepreg or composite expressed either as percent by weight or
percent by volume.
3.2.2.1 Discussion—In this test method the reinforcement is
separated from the remainder of the material, which includes
the matrix and the filler. If the filler is not then separated from
the matrix to determine the proportion of each, then the filler
content is included in the matrix content.
3.2.3 reinforcement content, n—the amount of reinforce-
ment present in a composite or prepreg expressed either as
percent by weight or percent by volume. This is sometimes
stated as a fraction, that is, reinforcement volume fraction.
3.2.4 replicate, n—a test specimen tested under nominally
identical conditions as other test specimens from the same
sample.
3.2.5 volatiles content, n—the amount of volatiles present in
a prepreg expressed as percent by weight.
3.2.6 wet resin content, n—prepreg resin content deter-
mined by considering volatiles as part of the resin mass.
3.3 Symbols:
3.3.1 A—initial mass of dry reinforcement during a reagent
exposure evaluation.
3.3.2 B—final mass of dry reinforcement during a reagent
exposure evaluation.
3.3.3 c—percent reinforcement mass change due to reagent
exposure.
3.3.4 CV—coefficient of variation statistic of a sample
population for a given property.
3.3.5 Ma—additional mass of filler in the test specimen.
3.3.6 Me—mass of the test specimen extraction residue.
3.3.7 Mi—initial mass of the test specimen.
3.3.8 Mr—mass of reinforcement in the test specimen.
3.3.9 n—number of replicates in the sample population.
3.3.10 sn−1—standard deviation statistic of a sample popu-
lation for a given property.
3.3.11 Wf—weight percent of filler in prepreg.
3.3.12 Wm—weight percent of matrix in prepreg.
3.3.13 Wr—weight percent of reinforcement in prepreg.
3.3.14 xi—test result for an individual test specimen from
the sample population for a given property.
3.3.15 x̄—average value of a sample population for a given
property.
4. Summary of Test Method
4.1 The exposed surface area of the prepreg material test
specimen is increased by cutting the test specimen into smaller
pieces. The test specimen is weighed and the matrix material
removed by means of Soxhlet extraction. The extracted residue
is dried and weighed. If a filler is present in the residue, in
addition to reinforcement, the two components are separated
by filtering the residue. From mass measurements of the initial
test specimen, and of the residue taken at various stages in the
process, the matrix content, reinforcement content, and filler
content are calculated and reported in weight percent.
4.1.1 Soxhlet Process—While described in detail in com-
mon quantitative chemical analysis textbooks, the Soxhlet
process is summarized as follows. The test specimen is loaded
into a filtering extraction thimble, which is placed into the
extraction chamber of a Soxhlet extraction assembly (see Fig.
1) containing an appropriate extraction reagent. The porous
thimble allows the liquid extraction reagent to pass while
retaining the test specimen. Freshly distilled liquid reagent
enters from the top of the extraction chamber, filling it until the
liquid reaches the highest level of the reagent-return tube. At
this moment the tube operates as a siphon, draining the
extraction chamber completely as it returns the liquid reagent
and any extracted material to a reservoir beneath the extraction
chamber. The heated reservoir boils the reagent, the vapor of
4 SeeForm and Style for ASTM Standards. FIG. 1 Schematic of Soxhlet Extraction Apparatus
C 613/C 613M – 97 (2003)e1
2
which is led to a condenser placed above the extraction
chamber. The distilled condensate then drips down into the
thimble, starting once again the process of filling the extraction
chamber. The Soxhlet operation is not a continuous operation,
but rather a sequence of fillings and siphonings, each cycle of
which is called a reflux change. The heat input and reagent
volume are adjusted to cause the boiling reagent to return to the
extraction flask from the condenser at 3 to 10 reflux changes
per hour, with the extraction continuing for a minimum of 4 h
or 20 reflux changes, whichever comes first.
4.1.2 Volatiles Content—Volatiles content is primarily ap-
plicable to thermosetting materials, and, if required, is deter-
mined by Test Method D 3530/D 3530M. Volatiles content
determination requires different test specimens than those used
in the extraction process, since the process of determining
volatiles content renders thermosetting material specimens
unsuitable for subsequent organic solvent extraction.
5. Significance and Use
5.1 The prepreg volatiles content, matrix content, reinforce-
ment content, and filler content of composite prepreg materials
are used to control material manufacture and subsequent
fabrication processes, and are key parameters in the specifica-
tion and production of such materials, as well as in the
fabrication of products made with such materials.
5.2 The extraction products resulting from this test method
(the extract, the residue, or both) can be analyzed to assess
chemical composition and degree of purity.
6. Interferences
6.1 Extent of Cure in Thermosetting Systems—The effi-
ciency of extraction for thermosetting matrix materials is
directly related to the extent of cure of the resin system. Resins
that have started to cross-link (such as B-staged resins) will be
increasingly more difficult to extract as the cure advances. This
test method may not be appropriate for such materials; Test
Methods D 3171 or D2584 may be better test method choices.
6.2 Reagent Selection—The proper reagent, in a suitable
quantity, must be selected for the constituents under test. The
reagents listed in Section 8 are provided for consideration,
particularly with regard to thermosetting materials, but cannot
be assured to perform well on all material systems within the
scope of this test method.
6.3 Thimble Contamination—If the extract is to undergo
further analysis, the thimble must be clean to avoid a signifi-
cant source of contamination.
6.4 Reinforcement Mass Change As a Result of Reagent—
The calculations of this test method assume that the reinforce-
ment mass (or filler, if filler content is being determined) is not
significantly affected (whether mass increase or mass loss) by
exposure to the reagent. Small, consistent changes in the
reinforcement mass caused by exposure to the reagent can be
corrected by the process described in 14.4.5. The resulting
correction may be used if this change is sufficiently reproduc-
ible under the conditions of the test, and if this change has the
same value for the reinforcement alone as for the reinforcement
in the matrix. Otherwise, a different reagent, or another test
method, must be selected.
7. Apparatus
7.1 General Requirements:
7.1.1 Container Volume—A suggested volume is shown for
each container. However, other sizes may be required depend-
ing upon the test specimen size, the amount of reagent needed
to complete the extraction process, and the relative sizes of
related equipment.
7.1.2 Thermal Shock—Laboratory equipment that is sub-
jected to non-ambient temperatures (hot or cold) shall be of
tempered-glass or PTFE materials.
7.1.3 Post-Test Elemental Analysis—If a post-test elemental
analysis of the extract or residue is to be performed, laboratory
equipment contacting the test specimen shall be constructed of
PTFE and test specimen cutting shall be limited to tools that do
not leave an elemental trace.
7.2 General Equipment:
7.2.1 Analytical Balance—The analytical balance shall be
capable of reading to within60.1 mg.
7.2.2 Muffle Furnace—The muffle furnace used to condition
glass extraction thimbles shall be capable of maintaining a
temperature of 5106 15°C.
7.2.3 Air-Circulating Drying Oven—The drying oven shall
be capable of maintaining a temperature of 1636 3°C.
(Warning—For safety purposes listed in NFPA 86, take care to
limit volatile concentration in the oven by controlling sample
quantity, temperature, and ventilation.)
7.2.4 Desiccator—The desiccator shall be capable of con-
taining the required test specimens.
7.3 Extraction Assembly:
7.3.1 Extraction Thimbles—The extraction thimbles shall
be deep, narrow filtering cups, of either borosilicate glass in an
appropriate pore size, or fat-extracted cellulose paper, suitable
for use in the extraction chamber.
7.3.2 Hot Plate—The hot plate shall have adjustable con-
trols suitable for heating the reagent within the reservoir flask
to 260°C and shall be capable of controlling the required
reagent temperature within615°C.
7.3.3 Reservoir Flask—The reservoir flask shall be of
borosilicate glass, of suitable volume (125 mL is suggested) for
the reagent quantity and extraction chamber volume, and shall
have a ground tapered joint capable of connection with the
remainder of the assembly.
7.3.4 Soxhlet Extraction Chamber—The extraction cham-
ber shall be of borosilicate glass, with an automatic recycling
siphon that recycles at a suitable liquid volume (50 mL is
suggested), and with a ground tapered joint at each end capable
of connecting with the remainder of the assembly.
7.3.5 Condensing Chamber—The condensing chamber
shall be of borosilicate glass, shall be water cooled, and shall
have a ground tapered joint capable of connecting with the
remainder of the assembly.
7.4 For Determining Filler Content:
7.4.1 Vacuum Filter System—The vacuum filter system
shall be suitable for filtering material from the filtering crucible
and holder.
7.4.2 Filtering Crucible—The filtering crucible shall be of
fritted glass and of suitable pore size and of appropriate volume
(30 mL is suggested).
C 613/C 613M – 97 (2003)e1
3
NOTE 1—Filter porosity should be sized to filter the smallest expected
filler size from the reinforcement. If there is any doubt about the filter
pore-size selection, evaluate, with the material under test, filters of
successively different porosity size until confidence is established in the
filter size selected. While the glass fiber filter is used in concert with the
fritted filter to reduce any tendency to clog, note that certain materials,
particularly those containing filler of a broad range of particle size and
shape, may nevertheless clog the filter pores without visible sign. The
filter tare mass should be monitored for change as a result of the test. A
change in the filter tare mass indicates a potentially incorrect determina-
tion of reinforcement to filler proportion, and therefore, incorrect rein-
forcement and filler content test results.
7.4.3 Crucible Holder—The crucible holder shall be ca-
pable of holding the filtering crucible.
7.4.4 Glass Fiber Filter—A glass fiber filter of suitable
porosity and of appropriate diameter to fit in the filtering
crucible.5
7.5 Miscellaneous Common Laboratory Items—Other com-
monly available laboratory items may be needed including:
scissors or knife, beakers or flasks, flexible tubing, equipment
connectors, wash bottles, aluminum foil, and lint-free wipes.
8. Reagents and Materials
8.1 Purity of Reagents—As a minimum, a technical-grade
reagent is required to provide accurate results. However, when
resolving disputes or performing subsequent analysis of extract
or residue, a reagent-grade reagent shall be used. Unless
otherwise indicated, it is intended that the reagent conform to
the specifications of the Committee on Analytical Reagents of
the American Chemical Society, where such specifications are
available.6 Other equivalent grades may be used, provided the
reagent is of sufficiently high purity to permit its use without
lessening the accuracy of the determination.
8.2 Extraction Reagents—A suitable extraction reagent
shall be selected that is compatible with the material system
under test and the apparatus. Read and understand the precau-
tions listed in Section 9 before selecting an extraction reagent.
Extraction reagents that have been found effective for many
thermosetting matrices include the following:
8.2.1 Dimethylformamide (DMF), (CH5)2NCHO.
(Warning—As of the approval date of this standard, DMF was
listed by the International Agency for Research on Cancer in
Group 2B as a “possible human carcinogen” and is considered
a reproductive toxin by the National Toxicology Program. See
a recent DMF material safety data sheet for more information.)
8.2.2 Ethanol (Ethyl Alcohol), C2H5OH.
8.3 Washing Reagents—A suitable washing reagent(s) shall
be selected that is compatible with the material system under
test and the apparatus. Read and understand the precautions
listed in Section 9 before selecting a washing reagent. Washing
reagents that have been found effective include the following:
8.3.1 Acetone (2-Propanone), CH8COCH8.
8.3.2 Water, Distilled or Demineralized.
9. Hazards
9.1 This test method should be used only by laboratory
workers with general training in the safe handling of chemi-
cals. A source of useful information is given in Footnote 10.7
(Precaution—In addition to other precautions, consult the
appropriate material safety data sheet for each material used,
including reagent materials and test specimen materials, for
specific recommendations on safety and handling.)
(Precaution—In addition to other precautions, the extraction
and filtering processes should be performed under a suitable
vented chemical fume hood.) (Precaution—In addition to
other precautions, materials that have been exposed to poten-
tially toxic or flammable reagents must be air-dried under a
hood before being subsequently oven-dried, to eliminatebuild-up of a potentially dangerous concentration of vapor in
the drying oven. Useful guidelines for estimating the safe
volatiles mass for a given oven size are given in NFPA
Standard 86.)
9.2 Use of mixed extraction reagents with different boiling
points are not covered by this test method. (Precaution—In
addition to other precautions, do not use mixed extraction
reagents with different boiling points. Use of mixed extraction
reagents with different boiling points can result in an explosion
if the low-boiling fraction siphons into the extraction chamber
while the high-boiling fraction is being heated; the low-boiling
fraction may then superheat and overpressure the apparatus.)
10. Sampling, Test Specimens, and Test Units
10.1 Test Units—Unless otherwise specified, the test unit
shall consist of a single test specimen upon which a single
observation is to be made.
10.2 Sampling—Unless otherwise specified, at least three
test specimens (test units) per sample shall be evaluated. For
statistically significant data the procedures outlined in Practice
E 122 should be consulted. The method of sampling shall be
reported.
10.3 Test Specimen Geometry—The mass of each individual
test specimen shall be at least 1.0 g and, unless otherwise
specified, shall be 2.0 to 3.0 g.
10.4 Test Specimen Preparation:
10.4.1 Labeling—Label each test specimen container so
that they will be distinct from each other and traceable back to
the sampled material. Report the labeling scheme and method.
11. Preparation of Apparatus
11.1 Clean the extraction thimbles and filter crucibles. Dry
the filter crucibles (including the glass fiber filters) and
extraction thimbles in the drying oven (unless otherwise
specified, dry at 1636 3°C) until there is no perceptible mass
change with time. Remove from the oven and cool in the
desiccator. Determine and record, to within 0.1 mg, the initial
tare mass of each. The tare mass of the filter crucibles shall
include the installed glass-fiber filter.
5 A Reeve Angle Grade 934 AH or equivalent is suggested.
6 Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
listed by the American Chemical Society, seeAnalar Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and theUnited States Pharmacopeia
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD.
7 Prudent Practices in the Laboratory: Handling and Disposal of Chemicals,
National Academy Press, 1995.
C 613/C 613M – 97 (2003)e1
4
11.2 After cleaning, drying, and taring, store all extraction
thimbles and filter crucibles in the desiccator until use.
12. Calibration and Standardization
12.1 All measuring equipment shall have certified calibra-
tions that are current at the time of use of the equipment. The
calibration documentation shall be available for inspection.
13. Conditioning
13.1 No preconditioning or conditioning of the test speci-
men is required.
13.2 Unless otherwise specified, conduct the tests at 236
3°C and 506 10 % relative humidity. Record and report the
actual laboratory environment.
14. Procedures
14.1 Selection of Test Parameters—Specify the following
test parameters, as applicable, prior to test.
14.1.1 Test Results—Specify the properties to be deter-
mined by this test method, including: volatiles content, matrix
content (dry, wet, or both), and reinforcement content. If no
properties are specified, determine and report only matrix
content (wet resin content) and reinforcement content, and
filler content if appropriate.
14.1.2 Reagent Selection—Specify the reagents (Section 8)
to be used for extraction and washing. If appropriate reagents
are not specified, or not known, contact the material manufac-
turer for guidance on reagent selection.
14.1.3 Sampling Method—Specify the material sampling
method, if sampling is to be conducted by the testing labora-
tory.
14.2 General Instructions:
14.2.1 Report any deviations from this test method, whether
intentional or inadvertent.
14.2.2 Shield the balance from air drafts and isolate it from
vibrations that could affect its accuracy.
14.2.3 Determine mass to the nearest 0.1 mg.
14.2.4 Process each test specimen separately.
NOTE 2—Reagent quantities and container volumes in this test method
are estimates based on common material systems and the standard test
specimen mass. Reagent quantities and equipment sizes may need to be
adjusted as a function of material system, coupon size, or both.
14.3 Volatiles Content—If volatiles content is to be deter-
mined on the same number of additional and separate test
specimens, each sampled immediately adjacent to one of the
extraction test specimens, determine and report volatiles con-
tent in accordance with Test Method D 3530/D 3530M. If the
dry resin content is required, the average volatiles content from
these tests will be used to correct the extraction results.
NOTE 3—Volatiles content is conducted on separate test specimens
since the process of determining volatiles content tends to advance
thermosetting resins, making subsequent resin extraction by this test
method difficult or impossible.
14.4 Extraction:
14.4.1 Cutting—Cut the prepreg test specimen into small
pieces (nominally 10 to 15-mm squares), place the pieces into
a clean, dry, tared extraction thimble, and blend the pieces
thoroughly. Take care during cutting and blending to avoid
losing even small quantities of matrix or reinforcement.
14.4.2 Initial Mass—Weigh the test specimen and thimble,
subtract the tared mass of the thimble, and record this result as
Mi, the initial test specimen mass.
14.4.3 Refluxing:
14.4.3.1 Setup the extraction apparatus under a suitably
vented chemical fume hood.
14.4.3.2 Position the thimble within the extractor. Add
extraction reagent to the extraction tube sufficient to immerse
the test specimen and fill about2⁄3 of the thimble (typically 35
mL of reagent).
14.4.3.3 Assemble the Soxhlet extractor to the reservoir
flask containing additional reagent (typically 55 mL of reagent,
for a total of about 90 mL of reagent in the assembly). Attach
the condenser to the top of the extractor and provide supports
for the entire assembly as needed.
14.4.3.4 Turn on the condenser cooling water.
14.4.3.5 Set the hot plate temperature control to a tempera-
ture appropriate for the selected reagent and turn on the hot
plate. When condensation of the reagent occurs, adjust the hot
plate temperature to effect 3 to 10 reflux changes per hour.
Continue to reflux for a minimum of 4 h or 20reflux changes,
whichever comes first.
NOTE 4—If the extractor volume is too large compared to the volume of
the liquid in the reservoir, with each cycle the siphoning liquid may cool
the reservoir below the reagent boiling point, and a stable process may be
difficult to obtain. A magnetically driven stirrer placed in the reservoir may
help.
NOTE 5—For high boiling reagents it may be necessary to wrap the
extraction chamber with aluminum foil to reduce heat loss.
14.4.3.6 When extraction is completed, turn off the hot plate
and allow the apparatus to cool until safe to handle. Remove
the extraction thimble from the extraction assembly, drain any
remaining reagent, and air-dry under a hood until any flam-
mable or toxic materials have evaporated. Complete the drying
to essentially constant mass in the forced-air drying oven at
163 6 3°C. Examine the residue for signs of incomplete
extraction. If matrix material remains, repeat the extraction
until extraction is complete, either with the original reagent or
with an alternate reagent.
14.4.3.7 Weigh the test specimen and thimble. Subtract the
tare mass of the thimble from this result and record asMe, the
extracted test specimen residual reinforcement and filler mass.
14.4.4 Filler Content—If filler is known or suspected to
exist, or is visibly present in the extracted residue, filter the
extract to separate the filler from the reinforcement. Otherwiserecord the residual mass,Me, as the reinforcement mass,Mr.
14.4.4.1 Under a suitable vented chemical fume hood, wash
the extraction tube, reservoir flask, and extraction thimble
(including the extraction residue), using a wash bottle and
appropriate solvent wash, and saving all washings in a flask.
All visible filler must be washed from the apparatus in order for
filler content to be determined.
NOTE 6—If washing the extraction apparatus with solvent fails to
remove filler that is caked on the apparatus, the following procedure has
been used to remove carbonaceous filled phenolic resins. Similar proce-
dures may be developed for other material systems, if needed. Place the
air-dried apparatus in a muffle furnace at 4006 15°C for a minimum of
C 613/C 613M – 97 (2003)e1
5
1 h. Cool in a desiccator and then weigh. If the apparatus was pretared,
subtract the tare mass from these results and record the total as additional
filler mass,Ma, to be added to the filler mass. If the apparatus was not
pretared, determine the tare masses by inserting the apparatus into the
muffle furnace at 5406 15°C for a minimum of 1 h; cool in a desiccator,
then weigh, recording these weighings as the tared masses.
14.4.4.2 Place a tared filter crucible in a vacuum filtration
system. Filter the washings with this system through the filter
crucible, washing the residue clean of filler with a suitable
solvent until only the reinforcement remains.
14.4.4.3 Air-dry the filter crucible under a chemical fume
hood, then complete the drying process in the drying oven at
163 6 3°C, for a minimum of 1 h or until an essentially
constant mass is achieved. Cool the filter crucible in a
desiccator and weigh. Subtract the crucible tare mass from the
result and record the resulting reinforcement mass asMr.
14.4.5 Correction for Reinforcement Mass Change—If the
reagent is known (or observed) to create a significant change (>
63 %), or inconsistent change, or both, in the mass of the
reinforcement material, then replace the reagent with another
that has little to no effect on the reinforcement. Correct small,
consistent reinforcement mass changes by the following pro-
cess.
NOTE 7—Certain reinforcements may, when exposed to ambient hu-
midity, contain adsorbed or absorbed water up to a few weight percent.
Steps should be taken during this evaluation to control this adsorbed or
absorbed moisture, so that an accurate assessment of reinforcement
change due to reagent exposure may be made.
14.4.5.1 Measure out dry (no sizing or finish) reinforcement
material equal to the mass of reinforcement in the nominal test
specimen. Record this value asA, the initial mass of the dry
reinforcement.
14.4.5.2 Duplicate the extraction procedure used on the
prepreg, with the dry reinforcement material, exposing the dry
reinforcement to the reagent for the same length of time that
the prepreg was exposed.
14.4.5.3 Weigh the exposed dry reinforcement in the
thimble. Subtract the tared mass of the thimble from this result
and record this value asB, the final mass of the exposed dry
reinforcement. A correction to the final results is made by
calculation in 15.1, based on any change in reinforcement mass
resulting from this exposure.
15. Calculation
15.1 Reinforcement Mass Change Due to Reagent
Exposure—Calculate the reinforcement mass change (loss or
gain) due to reagent exposure in accordance with Eq 1,
reporting the test result to the nearest 0.1 %.
c 5
A 2 B
A 3 100 (1)
where:
c = percent reinforcement mass change due to reagent
exposure, %,
A = initial mass of dry reinforcement, g, and
B = mass of dry reinforcement after exposure to reagent, g.
NOTE 8—A positive value forc indicates a mass loss due to reagent
exposure, while a negative value indicates a mass gain due to reagent
exposure.
Do not use the mass change,c, in subsequent calculations ifc is greater
than −0.5 % but less than +0.5 %.
15.2 Reinforcement Mass—Calculate the reinforcement
mass of the test specimen in accordance with Eq 2, reporting
the test result to the nearest 0.001 g.
Mro 5
100Mr
1002 c (2)
where:
Mro = original reinforcement mass, g, and
Mr = measured remainder of reinforcement, g.
15.3 Reinforcement Content—Calculate the reinforcement
content (weight percent) of the test specimen in accordance
with Eq 3, reporting the test result to the nearest 0.1 %.
Wr 5 1003
Mro
Mi
(3)
where:
Wr = weight percent reinforcement, %,
Mro = original mass of reinforcement, g, and
Mi = initial mass of test specimen, g.
15.4 Matrix Content—Calculate the matrix content (wet
resin content) (weight percent) of the test specimen in accor-
dance with Eq 4, reporting the test result to the nearest 0.1 %.
Wm 5 1002 SMeMi 3 100D (4)
where:
Wm = weight percent of matrix, %, and
Me = mass of extracted residue, g.
15.5 Dry Resin Content—Where appropriate and required,
calculate the dry resin content (weight percent) of the test
specimen in accordance with Eq 5, reporting the test result to
the nearest 0.1 %.
Wm ~dry! 5
1002 Wr 2 VC
1 2 VC/100 (5)
where:
Wm(dry) = weight percent of matrix, %, and
VC = average volatiles content (weight percent)
from 14.3, %.
15.6 Filler Content—Calculate the filler content (weight
percent) of the test specimen in accordance with Eq 6,
reporting the test result to the nearest 0.1 %.
Wf 5 1002 Wr 2 Wm 1
1003 Ma
Mi
(6)
where:
Wf = weight percent of filler, %, and
Ma = additional filler mass cleaned from equipment, g.
16. Report
16.1 Report the following information, or references point-
ing to other documentation containing this information, to the
maximum extent applicable. Guides E 1309 and E 1471 may
be helpful to those reporting material descriptions, constituent
descriptions, or both.
C 613/C 613M – 97 (2003)e1
6
16.1.1 Reporting of items that are beyond the control of a
given testing laboratory, such as material details, shall be the
responsibility of the requestor.
16.1.2 The revision level or date of issue of this test method.
16.1.3 Any variations to this test method, anomalies noticed
during testing, or equipment problems occurring during testing.
16.1.4 Identification of the material tested including: mate-
rial specification, material type, material designation, manufac-
turer, manufacturer’s lot or batch number, source (if not from
manufacturer), date of certification or prepregging, expiration
of certification, filament diameter, tow or yarn filament count
and twist, sizing, form or weave, reinforcement areal weight,
and matrix type.
16.1.5 Method of preparing the test specimen, including test
specimen labeling scheme and method, test specimen geom-
etry, sampling method, and specimen cutting method.
16.1.6 Calibration dates and methods for all measurement
and test equipment, or a suitable reference to the same.
16.1.7 The type of apparatus used and the nominal and
actual test temperatures.
16.1.8 Relative humidity and temperature of the testing
laboratory.
16.1.9 Number of test specimens tested.
16.1.10 The matrix content (wet, dry, or both) of the test
specimen by weight percent;
16.1.11 The reinforcement content of the test specimen by
weight percent;
16.1.12 The filler content of the test specimen by weight
percent;
16.1.13 The volatiles content of the prepreg by weight
percent;
16.1.14 The percent reinforcement mass change due to
exposure to the extraction reagent.
16.1.15 The average value( x̄), standard deviation (sn−1),
and percent coefficient of variation (% CV) for the matrix
content, reinforcement content, filler content, and volatiles
content, for sample populations of three or more.
16.1.16 The date(s) and location(s) of the test(s); and
16.1.17 The name of the test operator(s).
17. Precision and Bias
17.1 Committee D30 is currently planning a round-robin
test series for this test method for the purpose of defining the
precision. Bias cannot be determined for this test method as no
reference material exists.
18. Keywords
18.1 composite materials; filler content; matrix content;
prepreg; reinforcementcontent; resin content; resin matrix
content; volatiles content
APPENDIX
(Nonmandatory Information)
X1. TEST DATA REPORTING FORM (Fig. 2)
C 613/C 613M – 97 (2003)e1
7
Composite Material Designation:
Reinforcement Designation:
Extraction Reagent:
FIG. X1.1 Example Test Data Reporting Form
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned
in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk
of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the
responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should
make your views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above
address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website
(www.astm.org).
C 613/C 613M – 97 (2003)e1
8
Designation: D 2344/D 2344M – 00 e1
Standard Test Method for
Short-Beam Strength of Polymer Matrix Composite Materials
and Their Laminates 1
This standard is issued under the fixed designation D 2344/D 2344M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
e1 NOTE—The title has been editorially corrected in November 2000.
1. Scope
1.1 This test method determines the short-beam strength of
high-modulus fiber-reinforced composite materials. The speci-
men is a short beam machined from a curved or a flat laminate
up to 6.00 mm [0.25 in.] thick. The beam is loaded in
three-point bending.
1.2 Application of this test method is limited to continuous-
or discontinuous-fiber-reinforced polymer matrix composites,
for which the elastic properties are balanced and symmetric
with respect to the longitudinal axis of the beam.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
1.4 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. The values stated in
each system may not be exact equivalents; therefore, each
system must be used independently of the other. Combining
values from the two systems may result in nonconformance
with the standard.
2. Referenced Documents
2.1 ASTM Standards:
D 792 Test Methods for Density and Specific Gravity (Rela-
tive Density) of Plastics by Displacement2
D 883 Terminology Relating to Plastics2
D 2584 Test Method for Ignition Loss of Cured Reinforced
Resins3
D 2734 Test Method for Void Content of Reinforced Plas-
tics3
D 3171 Test Method for Fiber Content of Resin-Matrix
Composites by Matrix Digestion4
D 3878 Terminology for High-Modulus Reinforcing Fibers
and Their Composites4
D 5229/D 5229M Test Method for Moisture Absorption
Properties and Equilibrium Conditioning of Polymer Ma-
trix Composite Materials4
D 5687/D 5687M Guide for Preparation of Flat Composite
Panels with Processing Guidelines for Specimen Prepara-
tion4
E 4 Practices for Force Verification of Testing Machines5
E 6 Terminology Relating to Methods of Mechanical Test-
ing5
E 18 Test Methods for Rockwell Hardness and Rockwell
Superficial Hardness of Metallic Materials5
E 122 Practice for Choice of Sample Size to Estimate a
Measure of Quality for a Lot or Process6
E 177 Practice for Use of the Terms Precision and Bias in
ASTM Test Methods6
E 456 Terminology Relating to Quality and Statistics6
E 1309 Guide for Identification of Composite Materials in
Computerized Material Property Databases4
E 1434 Guide for Development of Standard Data Records
for Computerization of Mechanical Test Data for High-
Modulus Fiber-Reinforced Composite Materials4
E 1471 Guide for Identification of Fibers, Fillers, and Core
Materials in Computerized Material Property Databases4
3. Terminology
3.1 Definitions—Terminology D 3878 defines the terms re-
lating to high-modulus fibers and their composites. Terminol-
ogy D 883 defines terms relating to plastics. Terminology E 6
defines terms relating to mechanical testing. Terminology
E 456 and Practice E 177 define terms relating to statistics. In
the event of a conflict between definitions, Terminology
D 3878 shall have precedence over the other documents.
NOTE 1—If the term represents a physical quantity, its analytical
dimensions are stated immediately following the term (or letter symbol) in
fundamental dimension form, using the following ASTM standard sym-
bology for fundamental dimensions, shown within square brackets: [M]
for mass, [L] for length, [T] for time, [Q] for thermodynamic temperature,
and [nd] for nondimensional quantities. Use of these symbols is restricted
to analytical dimensions when used with square brackets, as the symbols
may have other definitions when used without the brackets.
1 This test method is under the jurisdiction of ASTM Committee D-30 on
Composite Materials and is the direct responsibility of Subcommittee D30.04 on
Lamina and Laminate Test Methods.
Current edition approved March 10, 2000. Published June 2000. Originally
published as D 2344 – 65 T. Last previous edition D 2344 – 84 (1995).
2 Annual Book of ASTM Standards, Vol 08.01.
3 Annual Book of ASTM Standards, Vol 08.02.
4 Annual Book of ASTM Standards, Vol 15.03.
5 Annual Book of ASTM Standards, Vol 03.01.
6 Annual Book of ASTM Standards, Vol 14.02.
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 balanced laminate, n—a continuous fiber-reinforced
laminate in which each +u lamina, measured with respect to the
laminate reference axis, is balanced by a –u lamina of the same
material (for example, [0/+45/–45/+45/–45/0]).
3.2.2 short-beam strength, n—the shear stress as calculated
in Eq 1, developed at the specimen mid-plane at the failure
event specified in 11.6.
3.2.2.1 Discussion—Although shear is the dominant applied
loading in this test method, the internal stresses are complex
and a variety of failure modes can occur. Elasticity solutions by
Berg et al(1)7, Whitney (2), and Sullivan and Van Oene(3)
have all demonstrated inadequacies in classical beam theory in
defining the stress state in the short-beam configuration. These
solutions show that the parabolic shear-stress distribution as
predicted by Eq 1 only occurs, and then not exactly, on planes
midway between the loading nose and support points. Away
from these planes, the stress distributions become skewed, with
peak stresses occurring near the loading nose and support
points. Of particular significance is the stress state local to the
loading nose in which the severe shear-stress concentration
combined with transverse and in-plane compressive stresses
has been shown to initiate failure. However, for the more
ductile matrices, plastic yielding may alleviate the situation
under the loading nose(1) and allow other failure modes to
occur such asbottom surface fiber tension(2). Consequently,
unless mid-plane interlaminar failure has been clearly ob-
served, the short-beam strength determined from this test
method cannot be attributed to a shear property, and the use of
Eq 1 will not yield an accurate value for shear strength.
3.2.3 symmetric laminate, n—a continuous fiber-reinforced
laminate in which each ply above the mid-plane is identically
matched (in terms of position, orientation, and mechanical
properties) with one below the mid-plane.
3.3 Symbols:
b—specimen width.
CV—sample coefficient of variation (in percent).
Fsbs—short-beam strength.
h—specimen thickness.
n—number of specimens.
Pm—maximum load observed during the test.
xi—measured or derived property for an individual specimen
from the sample population.
x̄—sample mean (average).
4. Summary of Test Method
4.1 The short-beam test specimens (Figs. 1-4) are center-
loaded as shown in Figs. 5 and 6. The specimen ends rest on
two supports that allow lateral motion, the load being applied
by means of a loading nose directly centered on the midpoint
of the test specimen.
5. Significance and Use
5.1 In most cases, because of the complexity of internal
stresses and the variety of failure modes that can occur in this
specimen, it is not generally possible to relate the short-beam
strength to any one material property. However, failures are
normally dominated by resin and interlaminar properties, and
the test results have been found to be repeatable for a given
specimen geometry, material system, and stacking sequence
(4).
5.2 Short-beam strength determined by this test method can
be used for quality control and process specification purposes.
It can also be used for comparative testing of composite
materials, provided that failures occur consistently in the same
mode(5).
5.3 This test method is not limited to specimens within the
range specified in Section 8, but is limited to the use of a
loading span length-to-specimen thickness ratio of 4.0 and a
minimum specimen thickness of 2.0 mm [0.08 in.].
6. Interferences
6.1 Accurate reporting of observed failure modes is essen-
tial for meaningful data interpretation, in particular, the detec-
tion of initial damage modes.
7. Apparatus
7.1 Testing Machine, properly calibrated, which can be
operated at a constant rate of crosshead motion, and which the
error in the loading system shall not exceed61 %. The
load-indicating mechanism shall be essentially free of inertia
7 Boldface numbers in parentheses refer to the list of references at the end of this
standard.
NOTE 1—Drawing interpretation per ANSI Y14.5-1982 and ANSI/
ASM B46.1-1986.
NOTE 2—Ply orientation tolerance60.5° relative to –B–.
FIG. 1 Flat Specimen Configuration (SI)
D 2344/D 2344M
2
lag at the crosshead rate used. Inertia lag may not exceed 1 %
of the measured load. The accuracy of the testing machine shall
be verified in accordance with Practices E 4.
7.2 Loading Nose and Supports, as shown in Figs. 5 and 6,
shall be 6.00-mm (0.250-in.) and 3.00-mm (0.125-in.) diameter
cylinders, respectively, with a hardness of 60 to 62 HRC, as
specified in Test Methods E 18, and shall have finely ground
surfaces free of indentation and burrs with all sharp edges
relieved.
7.3 Micrometers—For width and thickness measurements,
the micrometers shall use a 4- to 5-mm (0.16- to 0.2-in.)
nominal diameter ball interface on an irregular surface such as
the bag side of a laminate and a flat anvil interface on machined
edges or very smooth tooled surfaces. A micrometer or caliper
with flat anvil faces shall be used to measure the length of the
specimen. The accuracy of the instrument(s) shall be suitable
for reading to within 1 % of the sample dimensions. For typical
section geometries, an instrument with an accuracy of60.002
mm (60.0001 in.) is desirable for thickness and width mea-
surement, while an instrument with an accuracy of60.1 mm
(60.004 in.) is adequate for length measurement.
7.4 Conditioning Chamber, when conditioning materials at
nonlaboratory environments, a temperature/vapor-level-
controlled environmental conditioning chamber is required that
shall be capable of maintaining the required temperature to
within 63°C (65°F) and the required vapor level to within
63 %. Chamber conditions shall be monitored either on an
automated continuous basis or on a manual basis at regular
intervals.
7.5 Environmental Test Chamber, an environmental test
chamber is required for test environments other than ambient
testing laboratory conditions. This chamber shall be capable of
maintaining the test specimen at the required test environment
during the mechanical test method.
8. Sampling and Test Specimens
8.1 Sampling—Test at least five specimens per test condi-
tion unless valid results can be gained through the use of fewer
specimens, as in the case of a designed experiment. For
statistically significant data, consult the procedures outlined in
Practice E 122. Report the method of sampling.
8.2 Geometry:
8.2.1 Laminate Configurations—Both multidirectional and
pure unidirectional laminates can be tested, provided that there
are at least 10 % 0° fibers in the span direction of the beam
(preferably well distributed through the thickness), and that the
laminates are both balanced and symmetric with respect to the
span direction of the beam.
8.2.2 Specimen Configurations—Typical configurations for
the flat and curved specimens are shown in Figs. 1-4. For
specimen thicknesses other than those shown, the following
geometries are recommended:
Specimen length = thickness3 6
Specimen width,b = thickness3 2.0
NOTE 2—Analysis reported by Lewis and Adams(6) has shown that a
width-to-thickness ratio of greater than 2.0 can result in a significant
width-wise shear-stress variation.
8.2.2.1 For curved beam specimens, it is recommended that
the arc should not exceed 30°. Also, for these specimens, the
specimen length is defined as the minimum chord length.
8.3 Specimen Preparation—Guide D 5687/D 5687M pro-
vides recommended specimen preparation practices and should
be followed where practical.
8.3.1 Laminate Fabrication—Laminates may be hand-laid,
filament-wound or tow-placed, and molded by any suitable
laminating means, such as press, bag, autoclave, or resin
transfer molding.
8.3.2 Machining Methods—Specimen preparation is impor-
tant for these specimens. Take precautions when cutting
specimens from the rings or plates to avoid notches, undercuts,
rough or uneven surfaces, or delaminations as a result of
inappropriate machining methods. Obtain final dimensions by
water-lubricated precision sawing, milling, or grinding. The
use of diamond tooling has been found to be extremely
effective for many material systems. Edges should be flat and
parallel within the specified tolerances.
8.3.3 Labeling—Label the specimens so that they will be
distinct from each other and traceable back to the raw material,
in a manner that will both be unaffected by the test method and
not influence the test method.
9. Calibration
9.1 The accuracy of all measuring equipment shall have
certified calibrations that are current at the time of use of the
equipment.
NOTE 1—Drawing interpretation per ANSI Y14.5-1982 and ANSI/
ASME B46.1-1986.
NOTE 2—Ply orientation tolerance60.5° relative to –B–.
FIG. 2 Flat Specimen Configuration (Inch Pound)
D 2344/D 2344M
3
10. Conditioning
10.1 Standard Conditioning Procedure—Unless a different
environment is specified as part of the test method, condition
the test specimens in accordance with Procedure C of Test
Method D 5229/D 5229M, and store and test at standard
laboratory atmosphere (236 3°C (736 5°F) and 506 10 %
relative humidity).
11. Procedure
11.1 Parameters to Be Specified Before Test:
11.1.1 The specimen sampling method and coupon geom-
etry.
11.1.2 The material properties and data-reporting format
desired.
NOTE 3—Determine specific material property, accuracy, and data-
reporting requirements before test for proper selection of instrumentation
anddata-recording equipment. Estimate operating stress levels to aid in
calibration of equipment and determination of equipment settings.
11.1.3 The environmental conditioning test parameters.
11.1.4 If performed, the sampling test method, coupon
geometry, and test parameters used to determine density and
reinforcement volume.
11.2 General Instructions:
11.2.1 Report any deviations from this test method, whether
intentional or inadvertent.
11.2.2 If specific gravity, density, reinforcement volume, or
void volume are to be reported, then obtain these samples from
the same panels as the test samples. Specific gravity and
NOTE 1—Drawing interpretation per ANSI Y14.5-1982 and ANSI/ASM B46.1-1986.
NOTE 2—Ply orientation tolerance60.5° relative to –A–.
FIG. 3 Curved Specimen Configuration (SI)
D 2344/D 2344M
4
density may be evaluated by means of Test Methods D 792.
Volume percent of the constituents may be evaluated by one of
the matrix digestion procedures of Test Method D 3171, or for
certain reinforcement materials such as glass and ceramics, by
the matrix burn-off technique of Test Method D 2584. Void
content may be evaluated from the equations of Test Method
D 2734 and are applicable to both Test Methods D 2584 and
D 3171.
11.2.3 Condition the specimens as required. Store the speci-
mens in the conditioned environment until test time, if the test
environment is different from the conditioning environment.
11.2.4 Following final specimen machining and any condi-
tioning, but before testing, measure and record the specimen
width and thickness at the specimen midsection and the
specimen length to the accuracy specified in 7.3.
11.3 Speed of Testing—Set the speed of testing at a rate of
crosshead movement of 1.0 mm (0.05 in.)/min.
11.4 Test Environment—If possible, test the specimen under
the same fluid exposure level as that used for conditioning.
However, if the test temperature places too severe requirements
upon the testing machine environmental chamber, test at a
temperature with no fluid exposure control. In this case, a
restriction must be placed upon the time from removal of the
specimen from the conditioning chamber until test completion
to inhibit nonrepresentative fluid loss from the specimen.
Record any modifications to the test environment and specimen
weight change after removal from conditioning until test
completion.
11.4.1 Monitor the test temperature by placing an appropri-
ate thermocouple at specimen mid-length to be located on the
NOTE 1—Drawing interpretation per ANSI Y14.5-1982 and ANSI/ASME B46.1-1986.
NOTE 2—Ply orientation tolerance60.5° relative to –A–.
FIG. 4 Curved Specimen Configuration (Inch Pound)
D 2344/D 2344M
5
underside of the beam.
11.5 Specimen Insertion—Insert the specimen into the test
fixture, with the toolside resting on the reaction supports as
shown in Fig. 5 or Fig. 6. Align and center the specimen such
that its longitudinal axis is perpendicular to the loading nose
and side supports. Adjust the span such that the span-to-
measured thickness ratio is 4.0 to an accuracy of60.3 mm
(0.012 in.). The loading nose should be located equidistant
between the side supports to within60.3 mm (0.012 in.). Both
the loading nose and side supports should overhang the
specimen width by at least 2 mm (0.08 in.) at each side. In the
case of the flat laminate test, each specimen end should
overhang the side support centers by at least the specimen
thickness.
11.6 Loading—Apply load to the specimen at the specified
rate while recording data. Continue loading until either of the
following occurs:
11.6.1 A load drop-off of 30 %,
11.6.2 Two-piece specimen failure, or
11.6.3 The head travel exceeds the specimen nominal thick-
ness.
11.7 Data Recording—Record load versus crosshead dis-
placement data throughout the test method. Record the maxi-
mum load, final load, and the load at any obvious discontinui-
ties in the load-displacement data.
11.8 Failure Mode—Typical failure modes that can be
identified visually are shown in Fig. 7. However, these may be
preceded by less obvious, local damage modes such as transply
cracking. Record the mode and location of failure, if possible
identifying one or a combination of the modes shown.
12. Calculation
12.1 Short-Beam Strength—Calculate the short-beam
strength using Eq 1 as follows:
Fsbs 5 0.753
Pm
b 3 h (1)
where:
Fsbs = short-beam strength, MPa (psi);
Pm = maximum load observed during the test, N (lbf);
b = measured specimen width, mm (in.), and
h = measured specimen thickness, mm (in.).
12.2 Statistics—For each series of test methods, calculate
the average value, standard deviation, and coefficient of varia-
tion (in percent) for each property determined as follows:
FIG. 5 Horizontal Shear Load Diagram (Curved Beam)
FIG. 6 Horizontal Shear Load Diagram (Flat Laminate)
D 2344/D 2344M
6
x 5 ~(
i–1
n
xi!/n (2)
sn–1 5Œ~(
i51
n
xi
2 – n~x!2 !/~n–1! (3)
CV5 1003 sn–1/x (4)
where:
x̄ = sample mean (average);
sn–1 = sample standard deviation;
CV = sample coefficient of variation, %;
n = number of specimens; and
xi = measured or derived property.
13. Report
13.1 Report the following information, or references point-
ing to other documentation containing this information, to the
maximum extent applicable (reporting of items beyond the
control of a given testing laboratory, such as might occur with
material details or panel fabrication parameters, shall be the
responsibility of the requester):
NOTE 4—Guides E 1309, E 1434, and E 1471 contain data reporting
recommendations for composite materials and composite materials me-
chanical testing.
13.1.1 This test method and revision level or date of issue.
13.1.2 Whether the coupon configuration was standard or
variant.
13.1.3 The date and location of the test.
13.1.4 The name of the test operator.
13.1.5 Any variations to this test method, anomalies noticed
during testing, or equipment problems occurring during testing.
13.1.6 Identification of the material tested including: mate-
rial specification, material type, material designation, manufac-
turer, manufacturer’s batch or lot number, source (if not from
manufacturer), date of certification, expiration of certification,
filament diameter, tow or yarn filament count and twist, sizing,
form or weave, fiber areal weight, matrix type, prepreg matrix
content, and prepreg volatiles content.
13.1.7 Description of the fabrication steps used to prepare
the laminate including: fabrication start date, fabrication end
date, process specification, cure cycle, consolidation method,
and a description of the equipment used.
13.1.8 Ply orientation and stacking sequence of the lami-
nate.
13.1.9 If requested, report density, volume percent rein-
forcement, and void content test methods, specimen sampling
method and geometries, test parameters, and test results.
13.1.10 Average ply thickness of the material.
13.1.11 Results of any nondestructive evaluation tests.
13.1.12 Method of preparing the test specimen, including
specimen labeling scheme and method, specimen geometry,
sampling method, and coupon cutting method.
13.1.13 Calibration dates and methods for all measurements
and test equipment.
13.1.14 Details of loading nose and side supports including
diameters and material used.
13.1.15 Type of test machine, alignment results, and data
acquisition sampling rate and equipment type.
13.1.16 Dimensions of each test specimen.
13.1.17 Conditioning parameters and results.
13.1.18 Relative humidity and temperature of the testing
laboratory.
13.1.19 Environment of the test machine environmental
chamber (if used) and soak time at environment.
13.1.20 Number of specimens tested.
13.1.21 Speed of testing.
FIG. 7 Typical Failure Modes in the Short Beam Test
D 2344/D 2344M
7
13.1.22 Maximum load observed during the test, for each
specimen.
13.1.23 Load-displacement curves for each specimen.
13.1.24 Failure mode of each specimen, identified if pos-
sible from Fig. 7.
14. Precision and Bias
14.1 Precision—Thedata required for the development of a
precision statement is not currently available for this test
method.
14.2 Bias—Bias cannot be determined for this test method
as no acceptable reference standard exists.
15. Keywords
15.1 composite materials; resin and interlaminar properties;
short-beam strength
REFERENCES
(1) Berg, C. A., Tirosh, J., and Israeli, M., “Analysis of Short Beam
Bending of Fiber Reinforced Composites,” inComposite Materials:
Testing and Design (Second Conference), ASTM STP 497, ASTM,
1972, pp. 206-218.
(2) Whitney, J. M., and Browning, C. E., “On Short-Beam Shear Tests for
Composite Materials,”Experimental Mechanics, Vol 25, 1985, pp.
294-300.
(3) Sullivan, J. L., and Van Oene, H., “An Elasticity Analysis for the
Generally and Specially Orthotropic Beams Subjected to Concentrated
Loads,” Composites Science and Technology, Vol 27, 1986, pp.
182-191.
(4) U.S. Department of Transportation, Federal Aviation Administration,
“Test Methods for Composites a Status Report: Volume III Shear Test
Methods,” Report No. DOT/FAA/CT-93/17, III, FAA Technical Cen-
ter, Atlantic City, 1993.
(5) Cui, W., Wisnom, M. R., and Jones, M., “Effect of Specimen Size on
Interlaminar Shear Strength of Unidirectional Carbon Fibre-Epoxy,”
Composites Engineering, Vol 4, No. 3, 1994, pp. 299-307.
(6) Adams, D. F. and Lewis, E. Q., “Current Status of Composite Material
Shear Test Methods,”SAMPE, Vol 31, No. 6, 1994, pp. 32-41.
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at
610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org).
D 2344/D 2344M
8
Designation: D 2507 – 93
Standard Terminology of
Rheological Properties of Gelled Rocket Propellants 1
This standard is issued under the fixed designation D 2507; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 These definitions2 cover the flow properties of gelled
propellants of interest to the aerospace industry.
2. Terminology
2.1 Definitions:
apparent viscosity(of a non-Newtonian fluid)——the viscos-
ity of a Newtonian fluid that produces the same reading in
the same apparatus under identical conditions.
Discussion—Avoidance of this artificial term is recom-
mended.
classification of fluids:
Class I—Newtonian Fluid— a fluid that exhibits a direct
proportionality between shear stress and shear rate in the
region of laminar flow.
DISCUSSION—The shear rate is independent of the time of application
of shear stress.
Class II—Non-Newtonian Shear-Thinning Fluid—a fluid in
which the shear stress is not directly proportional to the shear
rate and in which the shear stress-shear rate ratio decreases
as the shear stress increases.
(a) Type A—Plastic Fluid—a Class II fluid that exhibits a
change in shear rate directly proportional to the change in shear
stress above the yield stress.
(b) Type B—Pseudoplastic Fluid—a Class II fluid that
exhibits a shear stress-shear rate ratio that is independent of the
duration of application of shear stress.
(c) Type C—Thixotropic Fluid—a Class II fluid that
exhibits time-dependent, reversible changes of the shear stress-
shear rate ratio.
Discussion—The ratio decreases asymptotically with dura-
tion of shear.
Class III—Non-Newtonian Shear-Thickening Fluid—a
fluid in which the shear stress is not directly proportional to
the shear rates, and in which the shear stress-shear rate ratio
increases as the shear stress increases.
(a) Type A—Dilatant Fluid—a Class III fluid that exhibits
a shear stress-shear rate ratio that is independent of the duration
of application of shear stress.
(b) Type B—Rheopectic Fluid—A Class III fluid that
exhibits time-dependent, reversible changes of the shear stress-
shear rate ratio.
Discussion—The ratio increases asymptotically with dura-
tion of shear.
emulsion—a two-phase liquid system in which small droplets
of one liquid (the internal phase) are immiscible in, and are
dispersed uniformly throughout, a second, continuous liquid
phase (the external phase).
gel—a liquid containing a colloidal structural network that
forms a continuous matrix and completely pervades the
liquid phase.
Discussion—A gel deforms elastically upon application of
shear forces less than the yield stress. At shear forces above the
yield stress, the flow properties are principally determined by
the gel matrix.
viscosity—the ratio of shear stress to shear rate. For non-
Newtonian fluids, it is preferable to report shear stress and
shear rate.
Discussion—If the viscosity of such a fluid is reported, the
shear rate must be specified.
yield stress—the maximum shear stress that can be applied
without causing permanent deformation.
3. Keywords
3.1 terminology, Dilanant fluid; terminology, Newtonian
fluid; terminology, Non-Newtonian fluid; terminology, plastic
fluid; terminology, propellants; terminology, Rheopectic fluid;
terminology, Thixotropic fluid; terminology, yield stress
1 These definitions are under the jurisdiction of ASTM Committee F-7 on
Aerospace Industry Methods and are the direct responsibility of Subcommittee
F07.02 on Propellant Technology.
Current edition approved March 15, 1993. Published May 1993. Originally
published as D 2507 – 66 T. Last previous edition D 2507 – 70 (1983).
2 These definitions are identical in substance with the JANNAF definitions,“ A
Glossary of Rheological Terms,” Part I of“ Heterogeneous Propellant Characteriza-
tion,” Liquid Propellant Test Methods, March 1967, published by the Chemical
Propulsion Information Agency, Johns Hopkins University, Applied Physics Labo-
ratory, Johns Hopkins Rd., Laurel, MD 20707.
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meetingof the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, at the address shown below.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at
610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org).
D 2507
2
Designation: D 2508 – 93 An American National Standard
Standard Test Method for
Solid Rocket Propellant Specific Impulse Measurements 1
This standard is issued under the fixed designation D 2508; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the measurement of solid
propellant specific impulse values.
1.2 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
only.
2. Referenced Documents
2.1 ASTM Standards:
D 2506 Terminology Relating to Solid Rocket Propulsion2
2.2 Military Specification:
MIL-STD-292C3
3. Terminology
3.1 Definitions—Refer to Terminology D 2506 or Military
Specification MIL-STD-292C.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 mass of propellant, m—p, to be used in the calculation
of specific impulse, shall be the mass of propellant charged into
the motor.
3.2.1.1 An igniter correction shall be made, determined
either by experiment or calculation, when the theoretical value
of this correction exceeds 0.1 %.
3.2.1.2 The difference between before and after firing
weights shall be recorded as expended weight.
3.2.1.3 The percentage difference between expended weight
and propellant weight shall be recorded as either inerts
expended (if the expended weight is higher) or residue re-
tained. Values less than 0.2 % may be ignored.
3.3 Symbols:
3.3.1 total impulse— I 5 *A
GFdt.
3.3.2 burning time— tb 5 time from “B” to “ E”.
3.3.3 action time— ta 5 time from “B” to “ F”.
3.3.4 average pressure over burning time— P̄b 5
*B
E Pdt/tb.
3.3.5 average pressure over action time— P̄a 5
*B
E Pdt/ta.
3.3.6 measured specific impulse—Isp 5 I/mp, which is
corrected to standard conditions in accordance with Section 8.
4. Summary of Test Method
4.1 This test method sets forth the following:
4.1.1 A set of uniform designations to be used for the
calculations.
4.1.2 Precautions to be taken in experimental techniques.
4.1.3 Acceptable ranges of experimental conditions to as-
sure good results.
4.1.4 Uniform procedures for correcting measured values to
a standard of set conditions.
4.1.5 Limited thrust coefficient values for use with this
practice.
5. Significance and Use
5.1 It is recognized that the size and design of ballistic test
motors affect the determination of propellant specific impulse,
and it is not intended that results from this test method be used
to predict performance in motors of size or design widely
different from that tested.
6. Procedure
6.1 Assume a pressure-time or thrust-time trace as shown in
Fig. 1.
6.2 The following experimental criteria is recommended to
ensure meaningful values ofIsp:
4
6.2.1 Use a geometry that gives a relatively neutral
pressure-time trace, be essentially sliverless, and provides a
nominal 50-lb grain. A suggested method for achieving these
conditions is to use a thin-webbed cylindrical geometry with
ends uninhibited.
6.2.2 Use a geometry that also gives a value for throat-to-
port area ratio ofJ 5 At/Ap of less than 0.35.
6.2.3 Use nozzles that give values ofP̄a between 5.52 and
7.58 MN/m2 (900 and 1100 psia) to minimize the pressure
correction.
6.2.4 Use nozzles with an expansion ratio near optimum,
but such that no separation due to over-expansion takes place
during theequilibrium burning time (see Fig. 1,C to D).
1 This test method is under the jurisdiction of ASTM Committee F-7 on
Aerospace Industry Methods and is the direct responsibility of Subcommittee
F07.02 on Propellant Technology.
Current edition approved March 15 1993. Published May 1993. Originally
published as D 2508 – 66. Last previous edition D 2508 – 71 (1980)e1.
2 Annual Book of ASTM Standards,Vol 15.03.
3 Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700
Robbins Ave., Philadelphia, PA 19111-5094.
4 Procedures (except for specific impulse corrections in Section 6) used in this
practice were released by the Chemical Propulsion Information Agency, Johns
Hopkins University, Applied Physics Laboratory, Johns Hopkins Rd., Laurel, MD
20707 in August 1968, and are identical in substance to Publication No. 174,
“Recommended Procedures for the Measurement of Specific Impulse of Solid
Propellants.”
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
6.2.5 Use nozzles that have a conical nozzle with exit cone
half-angle of 156 1°.
6.2.6 Use nozzles that have graphite inserts.
6.2.7 Use nozzles that have a conical approach half angle of
40 6 10°.
6.2.8 Use nozzles that have a nozzle convergence ratio (inlet
area/throat area) greater than three.
6.2.9 Use nozzles that have a ratio of wall radius of
curvature at the throat-to-throat diameter greater than two.
6.2.10 Use nozzles that are insulated.
6.2.11 Use weighing equipment and techniques that assure
accuracy to within 0.1 % of the propellant weight.
6.2.12 Record and use barometric pressure at time of firing
as the basis for conversion to psia.
6.3 Specific impulse results are dependent upon care in
making measurements, weighing (including calibration of
scales and balances), alignment of the motors in test cells,
calibration of the load cells, pressure gages, and test instru-
ments, and data reduction.
7. Calculation
7.1 To obtain a standard value for the propellant specific
impulse, the measured specific impulse shall be corrected to
6.55 MN/m2 (1000 psia) average chamber pressure (based on
P̄a), 0° exit cone half-angle, and optimum expansion at
101.354 kN/m2 (14.7 psia) absolute. It is recommended that the
symbol for the standard specific impulse beIsps and that this
symbol be usedonly for those tests which conform toall
aspects of the correction procedure as follows:
Isps5 Isp @CF ~standard!/CF ~test!#
7.2 CF (standard) is a function only of the specific heat ratio
(g), and can be taken from Table 1 or calculated as in the
Annex A1.CF(test) can be calculated as in Annex A1, or can be
taken from the following relationship:
CF ~test! 5 CF ~vacuum! 2 e ~Pamb / P̄a!
CF (vacuum) 5 function ofg ande obtained from Table 1,
Fig. 2, or Fig. 3,
e 5 nozzle expansion ratioAe/At,
Pamb 5 barometric pressure measured at time of
firing, and
P̄a is defined in 3.3.5.
8. Interpretation of Results
8.1 Data may not be acceptable because of aberrations in the
traces due to one of many causes. It is therefore recommended
that the following tests be applied to each trace and only those
traces which meet all criteria to be used for computation of
Isps(the suggested symbol for standardizedIsp).
8.1.1 The trace should be neutral within the limits 0.90# P/
P̄b # 1.10 over the timeC to D (see Fig. 1).
8.1.2 The value ofP̄a should be between 5.52 and 7.58
MN/m
2
(900 and 1100 psi).
8.1.3 The tail-off portion of the trace should be limited by
the following: tb $ 0.87 ta, and*B
E , Pdt $ 0.95*B
F Pdt (See
Fig. 1).
9. Report
9.1 Report the propellant specific impulse.
10. Precision and Bias
10.1 Due to the complex natureof this test method and the
expensive equipment involved in the initial setup of the
apparatus, there is not a sufficient number of volunteers to
permit a cooperative laboratory program for determining the
precision and bias of this test method. If the necessary
volunteers can be obtained, a program will be undertaken at a
later date.
11. Keywords
11.1 propellant; solid; solid rocket propellants; specific
impulse
All point and average pressure values shall be expressed and used in psia.
A 5 zero time, t0.
B 5 time at which the chamber pressure, Pc, reaches 5 % of nominal value of Pa.
C and D 5 points of tangency with the “equilibrium” portion of the trace essentially as illustrated.
E 5 point on the pressure-time curve found by the intersection with the bisector of the angle between the two tangent lines at web burn-out.
F 5 time that the pressure reaches 55 % of nominal value of Pa on the decaying portion of the curve.
Gv5 time at the end of thrust, tf.
FIG. 1 Locations of Points on the Pressure/Thrust-Time Curve
D 2508
2
TABLE 1 Thrust Coefficients
NOTE 1—The following table presents the vacuum thrust coefficients as a function of nozzle expansion ratio for a range of gamma values. These
vacuum thrust coefficients were calculated for conical nozzles with 15° exit half-angles and were obtained from theAGC Solid Design Handbook, edited
by J. M. Haygood. The standard condition thrust coefficients for each gamma value are also included in the following table. Standard conditions are
defined as 6.55-MN/m2 (1000-psia) chamber pressure, an optimum expansion nozzle to 101.354 kN/m2 (14.7 psia) and 0° exit cone half-angle.
g 5 1.6 {
$a 5 0°
a 5 15°
e 5 0
e 5 7.0
CF(standard) 5 1.62049
CF(vacuum) 5 1.68811 g 5 1.20 {
$a 5
0°
a 5
15°
e 5 0
e 5 7.0
CF(standard) 5 1.59666
CF(vacuum) 5 1.66835
7.5 1.69851 7.5 1.67776
8.0 1.70804 8.0 1.68637
8.5 1.71682 8.5 1.69428
9.0 1.72496 9.0 1.70160
9.5 1.73253 9.5 1.70840
10.0 1.73960 10.0 1.71474
g 5 1.18 {
$a 5 0°
a 5 15°
e 5 0
e 5 7.0
CF(standard) 5 1.60813
CF(vacuum) 5 1.67801 g 5 1.22 {
$a 5
0°
a 5 1
5°
e 5 0
e 5 7.0
CF(standard) 5 1.58583
CF(vacuum) 5 1.65912
7.5 1.68790 7.0 1.65912
8.0 1.69695 7.5 1.66808
8.5 1.70529 8.0 1.67626
9.0 1.71300 8.5 1.68378
9.5 1.72018 9.0 1.69072
10.0 1.72687 9.5 1.69716
10.0 1.70316
D 2508
3
FIG. 2 Vacuum Thrust Coefficient Graph
D 2508
4
ANNEX
(Mandatory Information)
A1. CALCULATION OF THRUST COEFFICIENT
A1.1 CF is as calculated in Sutton,Rocket Propulsion
Elements,2nd Ed., p. 67, Eq 3 to 30 or Warren,Rocket
Propellants,p. 81, Eq 4 to 35, modified by the divergence
factor l as follows:
CF 5 l Hf~g! F1 2 SPePc D
~g21!/gGJ½ 1 SPePc 2 PambPe DAeAt
where:
l 5 (1 + cosa)/2,
a 5 nozzle divergence half-angle,
g 5 specific heat ratio,
f ~g! 5
2g 2
~g 2 1!
3 S 2g 1 1 D~g11!/~g21!
Pe 5 exit pressure,
Pamb 5 ambient pressure, andPc
Pc 5 chamber pressure.
A1.2 CF (standard)then reduces to:
FIG. 3 Vacuum Thrust Coefficient Nomograph
D 2508
5
CF~standard! 5 Hf~g! F1 2 S 14.71000D~g21!/gGJ½
A1.3 CF(test) then reduces to:
CF~test! 5
~1 1 cos 15°!
2 Hf ~g! F1 2 SPeP̄a D
~g21!/gGJ½
1 S PeP̄a 2 PambP̄a DAeAt
where:
Pamb 5 barometric pressure measured at the time of test,
and
Pe/ P̄a is determined from
SAeAt DS1l D 5
S 2g 1 1 D~g11!/@2~g21!#
SPeP̄a D
1/g H 2g 2 1F1 2 SPeP̄a D
~g21!/gGJ ½
andPe/ P̄a can be obtained from one-dimensional isentropic
flow tables by looking under an area ratio is numerically equal
to
~Ae/At!~1/g!.
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, 100 Barr Harbor Drive, West Conshohocken, PA 19428.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States. Individual
reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585
(phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (http://www.astm.org).
D 2508
6
Designation: D 2539 – 93 An American National Standard
Standard Test Method for
Shock Sensitivity of Liquid Monopropellants by the Card-
Gap Test 1
This standard is issued under the fixed designation D 2539; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 In considering the handling properties of a liquid pro-
pellant, serious consideration is given to the possibility of
hazard initiated by hydrodynamic shock. The consequences of
such a shock may include: (1) nonpropagating explosion, (2)
propagating but low-velocity detonation, and (3) propagating
high-velocity detonation. All three are hazards; the test de-
scribed herein is useful for one hazard only, namely propagat-
ing high-velocity detonation.
1.2 This standard should be used to measure and describe
the properties of materials, products, or assemblies in response
to heat and flame under controlled laboratory conditions and
should not be used to describe or appraise the fire hazard or
fire risk of materials, products, or assemblies under actual fire
conditions. However, results of this test may be used as
elements of a fire risk assessment which takes into account all
of the factors which are pertinent to an assessment of the fire
hazard of a particular end use.
1.3 This standard does not purport to address all of the
safety problems, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
1.4 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
only.
2. Summary of Test Method
2.1 This test method gives an evaluation of the sensitivity of
a high-energy liquid propellant in terms of a stack of plastic
cards inserted between a sample of liquid and a standard
booster charge of high explosive. The sensitivity value is taken
as the number of cards required to attenuate the booster shock
just enough that the liquid detonates in 50 % of the trials. For
an unknown liquid, 15 to 25 shots (requiring up to 1000 mL of
liquid) can be needed to define its sensitivity value. Because of
the destructive nature of the test, a sufficient supply of
expendable parts must be available before a sensitivity deter-
mination is attempted.
2.2 The card-gap test described is a measure of the hydro-
dynamic shock required to produce a stable, high-velocity
detonation in a 1-in. standard steel pipe. Because of the large
sample size subjected to this detonability test, the test is not to
be done in the laboratory. The advantages of the card-gap test
are its practical scale, reproducibility, and moderate material
cost. The interpretation of results of the test is a matter of
considerable judgment. While a propellant may show a low
sensitivity in the card-gap test, this does not preclude the
possibilityof other dangers. On the other hand, a very high
card-gap sensitivity does not always preclude the usability of
such a liquid propellant, since it is possible that suitable
engineering design can incorporate preventative measures
against propagation of detonation. It is known that the degree
of confinement, size, and material of the container, among
other parameters, influence detonation propagation; therefore,
the results of any specific test may be highly apparatus-
dependent.
NOTE 1—Gap tests for determining explosive sensitivity are new. A
technique of using paper cards for the gap materials and steep pipe for
containers was developed in England at the Explosives Research and
Development Establishment. The version described herein is essentially
the Naval Ordnance Laboratory modification. The test is valuable because
it yields reproducible data and it has been found that results of different
investigators show close agreement.
3. Significance and Use
3.1 The property measured is the tendency of a propellant to
undergo a high-order detonation when subjected to a given
hydrodynamic shock. One limitation of the test is the difficulty
of applying it to materials under conditions where the vapor
pressure exceeds 1 atm.
3.2 The test is valuable because it yields very reproducible
data, and it has been found that results of different investigators
show close agreement.
4. Apparatus
4.1 Cup—The liquid under test is held in a cylindrical steel
cup, closed at the bottom by a thin, flat diaphragm. It shall be
fabricated as follows (Fig. 1):
1 This test method is under the jurisdiction of ASTM Committee F-7 on
Aerospace Industry Methods and is the direct responsibility of Subcommittee
F07.02 on Propellant Technology.
Current edition approved March 15, 1993. Published May 1993. Originally
published as D 2539 – 66 T. Last previous edition D 2539 – 70 (1980).
This test method is identical in substance with the Card Gap Test for Shock
Sensitivity of Liquid Monopropellants recommended by the Interagency Chemical
Rocket Propulsion Group, and published by the Chemical Propulsion Information
Agency, Test No. 1, March 1960.
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
4.1.1 Each end of a section of 1-in. Schedule 40 extruded
black steel pipe shall be faced in a lathe to produce an overall
length of 3.0 in. (76.2 mm).
4.1.2 The pipe shall be degreased in a solvent bath. The
inside must be very smooth, clean, and free from pitting and
rust to facilitate coating. Superficial rust can be removed by
burnishing with a suitable wire brush.
4.1.3 The pipe shall be dipped into a bath of undiluted
polytetrafluoroethylene (PTFE) black enamel and set upright
on blotting paper for a draining period of at least 10 min. After
drying in an oven at 90°C for 10 min, it shall be baked at 380°C
for 15 min. The enamel coating produced in this manner
provides sufficient protection from liquids as corrosive as 90 %
nitric acid (HNO3) at room temperature. For further protection,
the pipe can be given supplemental coats of PTFE aqueous
dispersion. These shall be applied in exactly the same manner
as that used for the original coat of black enamel. Each coat can
be dried and fused before applying the next one.
4.1.4 The diaphragm shall be made from 0.003-in. (0.08-
mm) PTFE tape. As received from the manufacturer, the tape is
not suitable for use, since there are unrelieved stresses present
which produce wrinkling in the finished diaphragm. To correct
this condition, the material shall be annealed as follows: the
tape shall be cut into 13⁄4-in. (44.5-mm) lengths which are
placed between two pieces of glass-cloth tape. One layer of
these sandwiches shall be placed on a smooth sheet of stainless
steel and covered with a flat piece of asbestos paper1⁄16-in. (1.6
mm) thick. The entire assembly shall be baked in a furnace at
380°C for 30 to 40 min, after which time the oven shall be
turned off and allowed to cool for 1 to 2 h. After it is removed
from the furnace and cooled to room temperature, the tape is
ready for use.
4.1.5 The diaphragm shall be fused to the PTFE coating on
the pipe as follows: a piece of annealed tape shall be supported
on a cushion of six layers of glass cloth stacked on a solid
backing. The coated pipe shall be set on top of the tape,
weighted with 60 lb (27 kg), and heated for 15 min at 380°C.
The weight shall be kept in place during the 15-min cooling
period. Excess tape shall be trimmed off.
4.1.6 The finished cup shall be tested for leaks before use.
4.1.7 Alternatively, the diaphragm can be formed from
0.002-in. (0.05-mm) polyethylene film secured by a rubber
band or the cardboard spacer. The film shall be stretched taut
and is perfectly acceptable as long as it does not leak or react
with the liquid to be contained.
4.2 Booster—The booster charge shall consist of a cylindri-
cal tetryl pellet (Note 2) nominally 1 in. (25.4 mm) high by 15⁄8
in. (41.3 mm) in diameter, weighing about 50 g. The density of
these pellets should be 1.576 0.03 g/cm3 in accordance with
Army ordnance Drawing 82-3-591C.
NOTE 2—Pentolite maynot be substituted.
NOTE 3—Warning: Tetryl is a highly toxic material; those who handle
it should exercise particular care to avoid spreading the dust by contact of
the hands with other parts of the body. Frequent washing of the hands with
soap and water is desirable. Working garments should be free from
dust-collecting features such as trouser cuffs, and should be laundered
frequently. Although not regarded as unusually sensitive, tetryl is a very
powerful explosive and shall be handled with due respect. Rough or
careless treatment of any sort shall be entirely avoided.
4.3 Cards2—The variable gap shall be built from circular
cards, 1.55 in. (39.4 mm) in diameter, punched from cellulose
acetate sheet nominally 0.010 in. (0.254 mm) thick. The sheet
stock shall have smooth surfaces free from ripples, thick spots,
and dimples, and should be dimensionally stable; thickness
shall be held to close tolerances. Because of its thermoplastic
nature, acetate sheet is not suitable as a gap material where
sensitivity determinations are being carried out at temperatures
much in excess of 100°C. In the event that such investigations
are undertaken, it will be necessary to find a gap material
dimensionally stable at high temperature.
4.4 Target Plate—Following a test shot, evidence is re-
quired to show whether or not the liquid has detonated. This
evidence is provided by the condition of the target plate, a
cold-rolled mild steep plate 4 by 4 by3⁄8 in. (102 by 102 by 9.5
mm), which shall be placed in a horizontal position directly
above the cup. It shall rest on a cardboard collar which fits
tightly around the outside of the cup and supports the plate at
a distance of1⁄8 to 1⁄4 in. (3.2 to 6.4 mm) above the surface of
the liquid. A gap is recommended to prevent chemical reaction
between corrosive liquids and the target plate, and to prevent
heat transfer between plate and liquid in tests above or below
ambient temperature.
4.5 Detonator Support Block—The tetryl booster pellet
shall rest on a cylindrical block, 1.57 in. (39.9 mm) in diameter
and 1 in. (25 mm) high, aligned axially with the pellet. The
block shall be made from cork or soft wood, with a 0.280-in.
2 Eastman Kodak Co.’s Kodapak IV has been found satisfactory for this purpose.
TABLE 1 Typical Experimental Data From a Sensitivity
Evaluation
Shot
No.
No. of
Cards
ResultA
Shot
No.
No. of
Cards
ResultA
1 0 + 14 20 −
2 32 − 15 19 +
3 16 + 16 20 −
4 24 − 17 19 +
5 20 + 18 20 +
6 22 − 19 21 −
7 21 − 20 20 −
8 20 − 21 19 −
9 19 + 22 18 +
10 20 + 23 19 +
11 21 + 24 20 +
12 22 − 25 21 −
13 21 −
A Key: + 5 liquid detonated.
− 5 liquid failed to detonate.
TABLE 2 Data of Table 1, Arranged to Show 50 % Point
No. of CardsResult
0 +
16 +
18 +
19 ++++−
20 ++++−−−−
21 −−−−+
22 −−
24 −
32 −
D 2539
2
(7.11-mm) hole along its cylindrical axis. This hole shall be of
such diameter that the detonator will slide into it with a snug
push-fit. The block itself shall rest on the shoulder formed at
the junction of the pellet tube and support tube.
4.6 Detonator—Detonation in the booster pellet shall be
initiated by an electric blasting cap which fits snugly into the
hole drilled through the detonator support block, its tip just
touching the center of the bottom face of the pellet. The cap
used is known as the Engineer Corps Special, and is consid-
erably more powerful than the No. 8 commercial cap.
NOTE 4—Warning: Blasting caps contain primary explosives, which
are easily initiated by relatively mild physical shock. Consequently, every
precaution shall be taken by those who work with them, with particular
emphasis on gentle handling and protection from electrostatic charges.
Accumulation of static charges by personnel should be prevented by use
of all cotton clothing and special conductive shoes.
4.7 Charge Support—The various test components shall be
properly aligned in a vertical train. One convenient method
consists of a series of nested cardboard support tubes on a steel
firing pedestal, as shown in Fig. 2. Snugness of fit of the tubes
is critical. A set known as a NOLGAP assembly consists of one
support tube, one pellet tube, one coupling tube, and two collar
tubes. The firing pedestal supports the entire test assembly at a
convenient working height. Complete details of its construc-
tion are given in Fig. 3. An alternative charge assembly design
developed by Army Ballistic Missile Agency is shown in Figs.
4 and 5.
4.8 Firing Chamber—It is necessary to provide protection
from high-velocity shrapnel and some means of recovering the
target. In some instances it is also desirable to reduce noise
from the shot. One solution consists in using an all steel
chamber in the shape of a simple maze (Fig. 6). Less elaborate
structures have been developed at other laboratories and
function satisfactorily.
4.8.1 Another chamber is illustrated in Fig. 7. The rein-
forced concrete wall is employed to protect personnel who
conduct the test from a distance of 200 ft (61 m). This type of
enclosure is only acceptable where three sides of the test site
are unoccupied for a distance of several hundred feet, since it
is possible that some shrapnel may travel this distance. It is
recommended that the side apron of the metal shield be lined
with a layer of high-strength steel since this area sustains the
most severe damage. Additional liners can be welded on at the
site as needed. Fig. 8 illustrates another possible test shelter.
4.9 Firing Equipment—Before each shot, the firing circuit
should be tested for continuity with a blasting galvanometer.
The shot may conveniently be fired from the remote control
point by means of a portable “blasting machine.” The firing
line should consist of 16-gage or heavier duplex copper
conductor cable.
5. Hazards
5.1 Because of the fairly large quantities of explosives
involved in propagation tests, they cannot be performed in the
laboratory, but must be carried out at a suitable firing site.
Before attempting to employ the test, those lacking experience
should be thoroughly educated in the safe handling of explo-
sives. Special safety precautions are recommended wherever
hazards exist that are peculiar to the materials or procedures of
the test. No attempt has been made to treat the general aspects
TABLE 3 Abbreviated Procedure for Determination of 50 % Point for Various Materials With a Sharp Cutoff(After
Detonation on First Test at Zero Gap) A
Basic Test PatternB
Supplementary Tests Required
to Establish 50 % Point
Results of Supplementary TestsB
Designation
Number of Cards Number of Cards
50 % Point
N N + 1 N − 1 N + 2
I ++ −− none ... ... N + 1⁄2
II +− −+ none ... ... N + 1⁄2
III +− −− two tests at N − 1 −−
++
−+
...
...
...
N − 1
N
N − 1⁄2
IV ++ −+ two tests at N + 2 ...
...
...
−−
++
−+
N + 1
N + 2
N + 11⁄2
A Key: N 5 an integer
+ 5 detonation
− 5 no detonation
... 5 no tests needed
B For a particular number of cards the order in which the results are obtained is immaterial.
TABLE 4 Sample Determination of 50 % Point Using
Abbreviated Procedure
Step
No. of
Cards
Symbol
in Table 1
Result of Test
50 % Point 5 10 Cards
1 0 ... +
2 8 ... +
3 16 ... −
4 12 ... −
5 10 N +
6 11 N + 1 − basic test configura-
7 10 N − % tion
8 11 N + 1 −
9 9 N − 1 +supplementary test
10 9 N − 1 +
50 % Point 5 11.5 Cards
1 0 ... +
2 8 ... +
3 16 ... −
4 12 N + 2 −supplementary test
5 10 N +
6 11 N + 1 − basic test configura-
7 10 N + tion
8 11 N + 1 +
9 12 N + 2 +supplementary test
D 2539
3
of safety in explosives handling, since the literature ((1-7))3
amply cover this subject. State and local regulations concern-
ing transportation, storage and use of explosives should be
consulted and followed.
6. Preparation of Apparatus
6.1 The location of sensitivity value, of the 50 % point, for
a given liquid follows a fixed pattern. Unless there is some idea
of the sensitivity of the liquid beforehand, the first shot shall be
made at zero gap, that is, with no cards between booster and
cup. Failure of the liquid to detonate under this condition of
maximum shock means that the gap test is not capable of
measuring its sensitivity. If detonation does occur, the next shot
shall be made at an arbitrary value of 32 cards. If the liquid
fails to detonate at this value, half as many cards shall be used
for the next shot; if it detonates at 32 cards, twice as many shall
be used for the third shot. This procedure shall be continued
until, on thenth shot, a reversal in trend is observed, that is, a
transition from detonation to failure, or vice versa. The number
of cards for the next shot shall then be fixed halfway between
the number used in shotN and that used in shotN − 1. This
3 The boldface numbers in parentheses refer to the list of references at the end of
this test method.
FIG. 1 Cup Construction
D 2539
4
pattern shall be carried forward until a reversal in trend occurs
with a change of only one card. The ensuing shots shall be fired
by increasing the card number by one card after every
detonation, decreasing it by one card after every failure. As
successive shots are made in this manner, a symmetrical
distribution of detonations and failures soon becomes evident,
having as its midpoint the desired sensitivity value.
6.2 An example of what can be encountered experimentally
is given in Table 1. Table 2 presents the same data in an
arrangement more easily interpreted; a 50 % point of 20 cards
is clearly indicated.
6.3 For materials that have a very sharp cut-off, an alterna-
tive abbreviated procedure can be used. After a positive and a
negative test have been obtained which differ by only one card,
let N 5 the number of cards corresponding to this positive test
andN + 1 5 the number of cards corresponding to this nega-
tive test.
6.4 A basic test pattern consisting of four tests shall be
established by making one additional shot at bothN andN + 1
cards. The four possible results are shown in Table 3. If
patterns I or II are obtained, no further testing shall be required
to establish the 50 % point, and the results are as shown. If
patterns III or IV are obtained, two supplementary shots will be
needed at a particular card value to determine the 50 % point.
(One of these may already have been made in the previous
sequence.) These supplementary tests and the corresponding
FIG. 2 Test Assembly Showing Cardboard Tubes Sectioned
D 2539
5
values of the 50 % point are given in Table 3.
6.5 Two sample test procedures are given in Table 4. In
example “A,” two supplementary tests are necessary after the
basic test configuration is established. In “B,” one supplemen-
tary test is made before, and one after the basic test configu-
ration is obtained.
6.6 Because the test apparatus forcard-gap determinations
shall be outdoors, ambient temperatures and sample tempera-
tures are frequently below the desired range. Simple, yet
effective, temperature control can be provided by means of
insulated electrical heating tape wrapped around the sample
cup in conjunction with a thermocouple and relay. The expense
of making the heating tape an expendable item can be reduced
by fabricating the tape from3⁄16 by 0.003-in. (4.8 by 0.08-mm)
Nichrome ribbon and1⁄4-in. (6.4-mm) glass fiber sleeving.
7. Calibration
7.1 Comparison of sensitivity data from several sources will
be much better justified if each investigator “calibrates” his
system by running sensitivity determinations periodically on a
series of standard liquid propellants. Agreement among the
absolute values of card-gap sensitivity for the series of refer-
ence liquid propellants is not expected to be exact, especially
when temperature control is not provided, but the order in
which the sensitivity values fall should not be different from
the accepted order. A reference series of liquid propellants can
be as follows (in increasing order of card-gap values): unsym-
metrical dimethylhydrazine (or hydrazine) < nitromethane <
80 % nitromethane-20 % tetranitromethane < 40 %
nitromethane-60 % tetranitromethane < 90 % nitromethane-
10 % ethylenediamine.
FIG. 3 Firing Pedestal
D 2539
6
8. Procedure for Firing
8.1 The first operation in setting up a shot consists of
assembling the necessary components in the pellet tube. This
assembly is best carried out at a table or bench in a charge
preparation area near the firing chamber. Insert the tetryl pellet
in the tube and position it correctly by means of the detonator-
support block, which is pushed in behind the pellet until flush
with the end of the tube. It is essential that the variable gap
receive a booster shock of reproducible intensity from shot to
shot.
8.2 Place the desired number of cards at the other end of the
tube. Carefully push them down so as to lie flat on the upper
end of the pellet. Slide the centering collar tube onto the cup
and push the standoff collar tube just far enough over the
mouth of the cup to provide1⁄4-in. (6.4-mm) separation
between cup and target plate. Then insert this unit in the pellet
tube and carefully push down until the diaphragm at the bottom
of the cup makes good contact with the stack of gap cards.
8.3 Prepare the blasting cap by carefully removing it from
its cardboard packing tube and straighten the attached 12-ft
(4-m) leads. If these leads are not long enough for eventual
connection to the firing circuit at a safe distance from the firing
chamber, extension leads shall be used. By means of the
blasting galvanometer, check the extension leads for circuit
continuity to make sure that they are shorted out (connected
together) at the point where connection will be made to the
firing circuit. After carefully inserting the blasting cap into a
length of heavy steel pipe (12 in. (305 mm) long by 11⁄2 in.
(38.1 mm) in inside diameter by 21⁄4 in. (57.2 mm) in outside
diameter, preferably located behind a shield or around the
corner from the operator), a similar continuity test shall be
made to ensure that the wiring within the cap is not defective.
Then connect the cap leads to the extension leads by tight
twisting; take care to make sure that the two splices cannot
short out the cap by making contact with each other or with the
ground. If no extension leads are used, short the cap leads by
twisting together.
8.4 In the firing chamber, slide the support tube, slotted-end
up, down over the tip of the firing pedestal. Slide the coupling
tube over the upper end of the pellet tube for a distance of
about 3 in. (76 mm). Carefully push the blasting cap into the
hole in the cap-support block until its tip touches the lower face
of the tetryl pellet. Place the bottom of the pellet tube on top of
the support tube, taking care that the cap leads pass through the
slot. Slide the coupling tube down to encircle both support tube
and pellet tube. The firing pedestal ready for firing is shown in
Fig. 9.
8.5 Pour the liquid under test into the cup. The liquid level
shall be as high as possible without risking overflow and
consequence wetting of the standoff collar tube. Use of a
stirring rod to guide the liquid stream helps to minimize the
chance of spillage. Certain chemicals, such as hydrazine-
hydrazine nitrate, have produced fires with tetryl. It is impor-
tant to prevent careless spillage, or to ascertain that no
dangerous reaction can occur.
8.6 Carefully center the target plate over the cup.
8.7 Open the firing-circuit terminal box (locked safety box
“A”, Fig. 6), adjacent to the firing chamber. Check the circuit
leading to the control point for continuity, disconnect the
extension leads (or cap leads, if no extension leads are used)
FIG. 4 ABMA Modification of Test Assembly
FIG. 5 Components of ABMA Modification
D 2539
7
from each other, and connect them to the respective firing-
circuit terminals. Then at the control point at the remote end of
the firing circuit, unlock the terminal box (locked safety box
“B”, Fig. 6), and connect the blasting machine to the terminals
there. After sounding whatever warning device is used (siren,
horn, buzzer, etc.), fire the shot by operation of the blasting
machine.
8.8 Provision shall be made for adequate ventilation of the
firing chamber, for the gases present after a shot are usually
highly toxic. When such gases have dissipated, the firing
chamber can be entered (or opened) for recovery of the target
plate and preparation for the next shot.
9. Interpretation of Results
9.1 The punching of a clean hole through the plate shall be
taken as a positive test result. If the plate is unusually hard, it
may break up due to radial expansion of the explosion gases.
Either of these two phenomena shall be interpreted as a
positive result.
9.2 If the plate is substantially undamaged, this result shall
be taken as a negative one. If the plate is bulged or if a ripped
hole appears with the plate material substantially still attached,
a low-velocity propagation or incompletely developed detona-
tion is indicated. In order to avoid ambiguity this occurrence
shall arbitrarily be taken as a negative result. See Figs. 10 and
11.
9.3 Thus, in its present form, the test indicates only the
presence or absence of a steady detonation built up in the 3-in.
sample length.
9.4 Since a low-velocity propagation or incomplete detona-
tion is taken as a negative result, it must be reemphasized that
a zero or low card-gap value does not imply that the material
in question is incapable, under the proper circumstances, of
producing a destructive explosion.
10. Report
10.1 Report the average number of cards.
FIG. 6 Firing Site
D 2539
8
11. Precision and Bias
11.1 Precision:
11.1.1 The repeatability of this test method varies with the
material as follows:
11.1.1.1Nitromethaneshows approximately61 card.
11.1.1.2 Other materials are usually less than62 cards.
11.1.1.3Nitroglycerine shows up to610 cards.
11.2 Bias—The procedure in this test method has no bias
FIG. 7 Firing Site (Alternative)
FIG. 8 Firing Site (Alternative)
D 2539
9
because the value of the shock sensitivity is defined only in
terms of this test method.
12. Keywords
12.1 card-gap test; detonation; sensitivity; explosive sensi-
tivity; high velocity detonation; monopropellant; liquid; pro-
pellant; liquid; propellants; shock sensitivity
FIG. 9 Firing Pedestal Set-Up Ready for Firing (Mounting Tubes
Sectioned)
FIG. 10 Target Plate Before Firing and After Failure
FIG. 11 Target Plate After Liquid Detonation
D 2539
10
REFERENCES
(1) Blaster’s Handbook,Explosives Dept., E. I. duPont de Nemours and
Co., Wilmington, DE 19898, 1958, 14th ed.
(2) “Ordnance Safety Manual” (ORD M7-724), Ordnance Corps, Dept. of
the Army, 1951, as revised.
(3) “Stray Currents in Electric Blasting” (Data Sheet D-MIN. 2), National
Safety Council, 425 N. Michigan Ave.,Chicago, IL 60611, 1950.
(4) “Blasting from Electric Power Circuits” (Data Sheet D-MIN. 10),
National Safety Council, 425 N. Michigan Ave., Chicago, IL 60611,
1950.
(5) Sax, N. I.,Handbook of Dangerous Materials,Reinhold Publishing
Corp., 1959.
(6) “Motor Carriers’ Explosives and Dangerous Articles Tariff No. 10”
(I.C.C. Regulations for Transportation of Explosives and Other Dan-
gerous Articles by Motor, Rail and Water), American Trucking
Association, Inc., November 1958, as amended.
(7) “The Handling and Storage of Liquid Propellants,” Office of the
Director of Defense Research and Engineering, Liquid Propellant
Information Agency. Available from: Superintendent of Documents,
U.S. Government Printing Office, Washington, DC 20025, March
1961.
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, 100 Barr Harbor Drive, West Conshohocken, PA 19428.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States. Individual
reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585
(phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (http://www.astm.org).
D 2539
11
Designation: D 2540 – 93
Standard Test Method for
Drop-Weight Sensitivity of Liquid Monopropellants 1
This standard is issued under the fixed designation D 2540; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method2 covers the determination of the
sensitivity of liquid monopropellants to the impact of a drop
weight.
1.2 This standard should be used to measure and describe
the properties of materials, products, or assemblies in response
to heat and flame under controlled laboratory conditions and
should not be used to describe or appraise the fire hazard or
fire risk of materials, products, or assemblies under actual fire
conditions. However, results of this test may be used as
elements of a fire risk assessment which takes into account all
of the factors which are pertinent to an assessment of the fire
hazard of a particular end use.
1.3 This standard does not purport to address all of the
safety problems, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
1.4 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
only.
2. Summary of Test Method
2.1 A small sample of the liquid (0.03 mL) to be tested is
enclosed in a cavity (0.06 mL) formed by a steel cup, an elastic
ring, and a steel diaphragm (see Fig. 1). A piston rests on the
diaphragm and carries a vent hole which is blocked by the steel
diaphragm. A weight is dropped onto the piston. A positive
result is indicated by puncture of the steel diaphragm accom-
panied by a loud noise or severe deformation of the diaphragm
and evidence that the sample was completely consumed. The
sensitivity value for a given sample shall be expressed as the
height from which the specified weight is dropped for the
probability of explosion to be 50 %.
3. Significance and Use
3.1 In drop-weight testing of liquids, explosions are initi-
ated in a complex compression process involving the degree
and rate of pressurization, the thermodynamic gas properties,
heat transfer, hydrodynamic properties, etc. At this time, the
fundamental significance of the test cannot be exactly defined.
The test is considered useful, however, as a rapid and simple
means to rate sensitive liquids as to their relative explosive
sensitivity. Since it requires only a few grams of sample, it can
be an important laboratory tool to determine the handling
safety of new materials before substantial quantities are pre-
pared.
3.2 Tests in which the sample volume is varied (at constant
cavity volume of 0.06 mL) show that the degree of filling
affects the result. Note that the relationship between sensitivity
rating and sample volume is not a characteristic of the test
apparatus but is a function specific to each propellant. At 50 %
filling (0.03 mL of sample), the dependency of sensitivity on
sample volume is moderate so that the error in sample volume
measurement has a negligible influence. Tests show that the
delivered sample volume is reproducible to60.5 % when
measured by a fixed-stroke syringe, and 0.03 mL shall be the
standard sample volume.
3.3 If the objective justifies the greater effort, the sample
volume is varied leading to a plot such as shown in Fig. 2
which represents the relationship between sensitivity rating and
sample volume for the specific propellantn-propyl nitrate.
1 This test method is under the jurisdiction of ASTM Committee F-7 on
Aerospace Industry Methods and is the direct responsibility of Subcommittee
F 07.02on Propellant Technology.
Current edition approved March 15, 1993. Published May 1993. Originally
published as D 2540 – 66 T. Last previous edition D 2540 – 70 (1982)e1.
2 This method is identical in substance with the JANNAF method, “Drop Weight
Test,” Test Number 4, Liquid Propellant Test Methods, May 1964, published by the
Chemical Propulsion Information Agency, Johns Hopkins University, Applied
Physics Laboratory, Johns Hopkins Rd., Laurel, Md. 20810.
FIG. 1 Sample Cup Assembly
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
4. Apparatus
4.1 Sample Cup Assembly—The sample cup assembly is
shown in Fig. 1, and an exploded view in Fig. 3. The assembly
shall consist of the following parts:
Part No. Name
1 body
2 cup
3 O-ring (expendable)
4 diaphragm (expendable)
5 piston
6 ball
7 cap
Since the sample cup assembly is the critical part of the
drop-weight tester, detailed dimensions of its components are
given in Fig. 4.
4.2 Weight—The weight shall be one integral assembly,
weighing 2 kg 6 1 g (Fig. 5). The weight shall be held
suspended by an electromagnet. The electromagnet shall itself
be held in the first version of the drop-weight tester by a stud
at the top which fits in the recess formerly designed to hold and
release the weight. The release shall be tied down to hold the
magnet firmly in place. The present magnet plus weight shall
be of such a length that the scale on the right hand post will
read the correct drop height.
4.2.1 In using this weight, constant vigilance shall be
maintained to see that the weight tip does not become
excessively worn or damaged. If excessive wear is indicated
the apparatus should be rechecked on a standard sample.
Damaged weights should be discarded.
4.3 Drop-Weight Assembly(Fig. 6), consisting of a base
plate withfour leveling screws; column; two guide rods (one
graduated); body retainer; release mechanism, adjustable to
retain magnet; and top plate.
4.4 Tools, consisting of a torque wrench, 0 to 1.7-N·m (0 to
15-lb·in.) torque wrench adaptor to fit cap (part 7 of Fig. 4);
hypodermic syringe of fixed stroke; O-ring seating tool; brass
pick; and spanner wrench.
4.5 Expandables, such as O-rings: either AN 6227B-5 or
6.076 0.13-mm (0.2396 0.005-in.) inside diameter and
1.78-mm (0.070-in.) cross section width, made from MIL-P-
5516 elastomer, or both; and diaphragms of Type 302 stainless
steel 0.416 0.013 mm (0.0166 0.0005 in.) thick, 9.22 mm
(0.363 in.) in diameter.
5. Safety Precautions
5.1 A positive safety latch shall be provided to prevent
injury resulting from the premature fall of the weight. It is
realized that this test might be employed for the evaluation of
ultra-high-energy materials. This fact, combined with the
possibility of faulty fabrication of components, could result in
the production of shrapnel. It is therefore recommended that
the apparatus be shielded (Fig. 7).
5.2 If the test apparatus is to be employed for the evaluation
of toxic materials, or if toxic products may be formed from the
decomposition of the sample, necessary steps shall be taken to
prevent the buildup of dangerous concentrations of these
materials.
FIG. 2 Impact Sensitivity, H50, of NPN versus Sample Volume at
70°F (21.1°C) Using a 2-kg Weight
FIG. 3 Sample Cup Assembly, Exploded View
D 2540
2
6. Preparation of Apparatus
6.1 Experience has shown that an appreciable difference in
the behavior of the apparatus can result from the manner in
which it is mounted. Therefore, the following conditions shall
be met:
6.1.1 The machine shall be mounted on and firmly attached
to a solid concrete foundation, preferably anchored to the
foundation of the building.
6.1.2 The machine shall be perfectly plumb with guides
lubricated to minimize friction during the fall of the weight.
6.2 The drop-weight sensitivity of sensitive liquids is, or
course, dependent on the purity of the sample. The magnitude
of this dependency will vary with the material. If attempts are
being made to reproduce data obtained by other investigations,
care shall be taken to obtain samples having identical analyses.
Particular care shall be taken to keep the samples dry, as
moisture may have an adverse effect.
7. Procedure
7.1 Results of this test have been found to be temperature-
dependent. It is therefore very important to provide means to
thermostat the sample cups, pistons, body of the assembly, and
the liquid to be tested unless the whole equipment is kept in a
constant-temperature room. Make all tests at 21.16 1.1°C (70
6 2°F).
7.1.1 Clean and dry all components of the body assembly. It
is good practice to wash the metal parts in acetone and blow
out both the exhaust hole and the cup with clean dry air. Wipe
the cup clean with a tissue or soft cloth. After positive tests,
check the exhaust hole and ports of the piston to be sure they
are clear of the blown out section of the diaphragm. Note the
condition of the pistons and cups. Replace cracked, pitted, or
worn components.
NOTE 1—For temperature uniformity and speed of operation, it is
recommended that a separate cup and piston be used for each test in a
series. This also ensures that possible cup damage will not affect the
results of subsequent tests in the series.
7.1.2 Set the height by loosening the locking handle that
binds the release mechanism to the support column, and sliding
the mechanism until the height indicator is properly aligned
with the graduated guide rod. Tighten the locking handle and
set the safety latch.
7.1.3 Place an AN 6227B-5 O-ring in the bottom of the cup,
and with the brass O-ring seating tool force it down until it is
firmly seated.
7.1.4 Fill the syringe with liquid and sweep out all en-
trapped air; wipe the point of the needle free of liquid; lower
the point to the bottom of the cavity; carefully inject 0.03 mL
into the cavity.
7.1.5 Slide a diaphragm across the top surface of the cup so
that it drops flat onto the O-ring. Place the piston in the cup.
7.1.6 Place the cup in the body.
7.1.6.1 Jouncing or tilting of the cup prior to insertion in the
machine shall be avoided particularly for low-viscosity liquids.
7.1.7 Place the ball on the top of the piston. Screw the cap
to the body and tighten with the torque wrench to 0.8 N·m (7
lb·in.) holding the body in a vise.
FIG. 4 Sample Cup Assembly, Detailed View
D 2540
3
7.1.7.1 Care must be taken to ensure that the small pellets
punched out of the diaphragm in positive tests do not get
lodged under the cup in the holder, under the holder on the
stand, or caught in the threads. If the operator notices some
slight blockage or stiffness due to dirt or a metal chip fouling
the threads, halt the test and clean the threads until they work
freely. If it becomes necessary to remove burrs which may
have developed on the threads, a fine lapping compound can be
worked into the threads, but it shall be removed and the threads
thoroughly cleaned before testing is continued. Use a thread
lubricant, but take great care not to overlubricate.
7.1.8 Place the body assembly into the retainer on stand.
Release the safety latch. Release the weight by de-energizing
the electromagnet. (See Fig. 8 for an illustration of the
first-bounce catching pin.)
7.1.9 Record the test result. A typical data sheet is shown in
Fig. 9.
7.1.10 Take the body assembly from the stand, remove the
cap by hand, or if jammed, by spanner wrench. Jamming will
often result from internal pressure after a combustion that did
not puncture the diaphragm. Remove the cup, lift the piston
out, and work the diaphragm free with a brass pick. Discard the
diaphragm and O-ring after each test (including negative tests).
7.1.11 Clean as described in 7.1.1.
8. Calculation
8.1 Calculate theH50 value as follows:
H50 5 H0 1 D@~(in/(n!6 1/2# (1)
FIG. 5 Two-Kilogram Weight and Electromagnet Release
FIG. 6 Drop-Weight Tester
FIG. 7 Drop-Weight Tester in a Protective Enclosure
D 2540
4
where:
D 5 interval between the trials (2 for the sample given),
Ho 5 height corresponding to the lowest level on which the
less frquent occurs (3 for the sample given), cm.
When positive trials are used for calculating theH50, the
minus sign is applicable. When negative trials are used the plus
sign is applicable.
9. Interpretation of Results
9.1 In some trials the sample will be found to have been
completely burned, but the diaphragm dimpled rather than
perforated, and gas pressure may be observed in the cavity. If
this reaction occurs, count the result as positive. Deformation
of the diaphragm can take place with large heights without
ignition of the sample. Examination of the sample holder will
allow such negative results to be distinguished from positive
because the cup will be wet with the sample, and no gas
pressure will be observed. Note all instances of this type in the
Remarks column of the data sheet (Fig. 9).
9.2 In some cases it has been observed that ignition of the
sample does not occur upon the initial impact, but does occur
following a second or third impact. Since the height associated
with subsequent impacts cannot be reproduced precisely, and
since the rating of the sensitive liquid is based on the initial
height of the weight, ignitions produced by more than one
impact shall not be counted as positive. A first-bounce catching
pin may be employed if differentiation cannot be made
between ignitions resulting from the first or subsequent im-
pacts. (See Fig. 8 for an illustration of the first-bounce catching
pin.)
9.3 If ten successive trials at the maximum height (50 cm)
are negative, discontinue and report the result as negative. If
the first trial at a 50 cm height is positive, conduct a second test
at 25 cm. If this second test is negative, testing shall be
continued by varying the height between 25 and 50 cm. Enter
the data as shown in Fig.9. Bracketing of the 50 percent point
shall be carried out by increasing the height after a negative
result and decreasing it after a positive result with the gap
continually narrowed by reducing the change in height by half
with each trial. When a change in sign (positive or negative) is
obtained with a change in height of 1 cm, a minimum of 20
trials should be conducted increasing the height by 1 cm when
a negative test occurs and decreasing it by 1 cm when a
positive test occurs.
9.4 If a trial at 2 cm is positive, repeat the trial for a
minimum of 6 times. If any negative results occur, the
bracketing procedure described in 9.3 should be employed. If
six positive results occur within 10 trials at the minimum
height, discontinue testing and report the 50 % point as less
than 1 cm.
9.4.1 The 50 % points for nitroglycerin, ethyl nitrate, and
diethyleneglycol dinitrate are all approximately 1 cm. Any
materials yielding positive results for heights at or below this
value are considered to be sensitive explosives. Handle with
extreme caution.
9.5 In this drop weight test, as in other sensitivity tests, the
critical stimulus needed for ignition may vary from trial to trial.
The height that yields a 50 % probability of ignition,H50, shall
be determined on several samples of the same material instead
of by direct and repeated measurements on a single sample and
shall be used as a measure of sensitivity. The test procedure
used is based on an established statistical method (known as
the“ up-and-down” method) for obtaining theH50 with a
minimum number of trials.
9.6 When a minimum of 20 trials has been completed, as
described in Section 7, the 50 % point can be determined by the
following analytical procedure: the points shall be marked on
the computation sheet. A typical computation sheet is shown in
Fig. 10 using ( + ) signs to indicate positive results and (0)
signs to indicate negatives. The total of positive and negative
results at each level shall then be indicated. For purposes of
computing the 50 % probability designatedH50, only the
positive or negative trials (whichever are present in smaller
number) shall be used. The trials to be used shall then be
tabulated. Under the column headedH, enter the levels in
centimeters at which trials were conducted starting from the
lowest in the first row. Under the column headedi, enter the
number of the levels in sequence starting from zero in the first
row. Under the column headedn, enter the number of trials at
each level. Under the columnin, enter the product of thei
column and then column for that level. Add the figures in the
column headedn and enter the total as(n at the bottom of the
column. Add the column headedin and enter the total as( in at
the bottom.
10. Report
10.1 Report theH50 value for the propellant tested along
with the properties of this test method.
FIG. 8 Close-Up of Drop-Weight Tester Showing a First-Bounce
Catching Pin
D 2540
5
11. Precision and Bias
11.1 Precision:
11.1.1 Repeatability experience with the apparatus has dem-
onstrated that the standard deviation will be about 1 cm.
11.1.2 Any new operator may wish to reassure his technique
by testing a liquid whose drop-weight rating has been well
established.n-Propyl nitrate (NPN) can be used for this
purpose. Typical results with NPN are shown in Fig. 9 and Fig.
10. The material as received was 99.9 % pure.
11.1.3 Data over the range 0.7 to 7 cm indicate that the
results submitted by each of two laboratories should be
considered suspect if they differ by more than 1.4 times their
mean.
11.2 Bias—The procedure in this test method has no bias
because the value of the drop-weight sensitivity is defined only
in terms of this test method.
12. Keywords
12.1 drop-weight sensitivity; explosive sensitivity; impact
test; monopropellant; liquid; propellant; liquid
FIG. 9 Typical Data Sheet
D 2540
6
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, 100 Barr Harbor Drive, West Conshohocken, PA 19428.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States. Individual
reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585
(phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (http://www.astm.org).
FIG. 10 Typical Computation Sheet
D 2540
7
Designation: D 2541 – 93
Standard Test Method for
Critical Diameter and Detonation Velocity of Liquid
Monopropellants 1
This standard is issued under the fixed designation D 2541; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method2 covers the evaluation of two proper-
ties of a high-energy liquid propellant. In one form, the critical
internal diameter is determined in a given type of metal or
plastic tubing below which propagation of stable high-velocity
detonation will not take place. In the alternative form, which
uses more material, detonation rate is concurrently measured.
The composite donor of either size may be used in most
instances to initiate detonation in experimental trap designs.
1.2 This standard does not purport to address all of the
safety problems, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
1.3 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
only.
2. Terminology
2.1 Definition:
2.1.1 critical diameter—the largest diameter that will not
detonate when the donor is exploded.
3. Summary of Test Method
3.1 Various diameters of tubing are filled with propellant,
and an attempt is made to cause the propellant to detonate by
use of a secondary detonating medium (the donor).
4. Significance and Use
4.1 It should be emphasized that the critical diameter, as
determined under these conditions, is valid only for these
conditions and is not an intrinsic property of the sample. One
vital parameter in establishing the critical diameter is that of
confinement of the test specimen. The fact that detonation
occurs or does not occur in Type 347 stainless steel tube does
not necessarily imply that the same results would be obtained
in an aluminum, copper, glass, etc., tube of similar dimensions.
Type 347 stainless steel tube is acceptable for a standard
reference test, but for practical application, diameters should be
studied in the materials and wall thicknesses proposed for use.
4.2 When working with high-energy liquid propellants,
serious consideration shall be given to the possibility that a
detonation originating in the engine can propagate upstream to
the propellant tank and cause a disastrous explosion. Therefore,
it is useful to know the minimum diameter of propellantline
through which a detonation of the propellant in question can
propagate. If it is impracticable to use propellant lines smaller
than this minimum, it will be necessary to design and test
detonation traps in larger lines. The minimum or critical
diameter (often referred to as “failure” diameter), when the
conditions are properly defined, can be a useful measure of the
shock sensitivity of similar systems. The detonation velocity of
the propellant in question is another property of interest.
4.3 The three determinations, namely: minimum diameter
for propagation, detonation trap requirements, and detonation
velocity, have much in common; all presuppose the initiation
of a stable detonation in a liquid contained in a tube. The key
to the present test method is the use of a donor stage consisting
of the material under test. Although a compound initiator
comprised of a blasting cap and high-explosive booster is
employed, the true donor is a length of the subject material
sufficient to assure establishment of a stable detonation char-
acteristic of the test medium ahead of the first test section or
measuring station. Questions of wall and boundary discontinu-
ity are thereby eliminated along with the accompanying
complications of impedance mismatch and perturbation of the
shock front.
5. Apparatus
5.1 The liquid under test, depending on what measurement
or measurements are to be made, shall be contained in one of
the following three assembled units:
5.1.1 Assembly No. 1, Critical Diameter Measurement(Fig.
1 (a)):
5.1.1.1 Section A, Fig. 1 (a), shall consist of Type 347
stainless steel tubing (1-in. (254-mm) outside diameter by
0.049-in. (1.24-mm) wall thickness by 6-in. (152-mm) length).
When filled with test sample, it is considered the “self donor”
section.
1 This test method is under the jurisdiction of ASTM Committee F-7 on
Aerospace Industry Methods and is the direct responsibility of Subcommittee
F07.02 on Propellant Technology.
Current edition approved March 15, 1993. Published May 1993. Orginally
published as D 2541 – 66 T. Last previous edition D 2541 – 83.
2 This test method is identical in substance with the JANNAF method,“ Critical
Diameter and Detonation Velocity Test,” Test Number 8, Liquid Propellant Test
Methods, May 1964, published by the Chemical Propulsion Information Agency,
Johns Hopkins University, Applied Physics Laboratory, Johns Hopkins Rd., Laurel,
MD 20707.
1
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
5.1.1.2 Section C, Fig. 1 (a), shall consist of Type 347
stainless steel tubing (30-in. (762-mm) length) of any one of
the following sizes:
Outside Diameter,
in. (mm)
Wall Thickness,
in. (mm)
1 (25.4) 0.049 (1.24)
3⁄4 (19.0) 0.049 (1.24)
5⁄8 (15.9) 0.035 (0.89)
1⁄2 (12.7) 0.035 (0.89)
3⁄8 (9.5) 0.035 (0.89)
1⁄4 (6.4) 0.035 (0.89)
1⁄8 (3.2) 0.020 (0.51)
When filled it is considered the “test” section.
5.1.1.3 Section A and Section C is connected by means of a
stopper of rubber or other suitable material compatible with the
propellant under test. The top of Section C is flush with the top
of the stopper.
5.1.1.4 The downstream end of Section C is closed by
crimping, plugging, or clamping, the latter being shown in Fig.
1 (a) and (c). A pinch clamp over vinyl tubing shall be used in
freeing the container, especially one of small diameter, of
entrapped air during the filling operation.
5.1.2 Assembly No. 2, Detonation Velocity Measurement
(Fig. 1 (b)):
5.1.2.1 Section D or “test” section, Fig. 1 (b), shall consist
of Type 347 stainless steel tubing (1-in. (25.4-mm) outside
diameter by 0.049-in. (1.24-mm) wall thickness by 11-in.
(279-mm) length). Two timing stations of either ionization
wires or T-1 targets (Note 1), 100 mm apart, and located at
approximately 5 and 9-in. (127 and 229-mm) levels from the
booster end, shall be used for the rate measurements. The
probes inserted in the container can be sealed with epoxy
cement or passed through neoprene sleeves, provided either is
compatible with the test liquid.
(a) T-1 targets are pressure-shorting switches encased in a
copper tube1⁄4 in. (6.4 mm) in diameter by 1 in. (25.4 mm)
long. These switches are inserted through holes in the side of
the container. (The same item in an aluminum case bears the
designation T-2 target.)
5.1.2.2 The downstream end of Section D is closed by
crimping or plugging.
5.1.2.3 A longer container and more distance between
stations, or a greater number of stations is required if greater
accuracy in rate measurement is required.
5.1.2.4 If the test sample is limited, smaller diameters can be
used.
5.1.3 Assembly No. 3, Combination Critical Diameter and
Detonation Velocity Measurement(Fig. 1(c)):
5.1.3.1 Section B, or “self donor” section, Fig. 1(c) (see
5.1.2.1).
5.1.3.2 Section C, or “test” section, Fig. 1(c) (see 5.1.1.2).
5.1.3.3 Section C, connection to Section B (see 5.1.1.3).
5.1.3.4 Section C, closure at bottom (see 5.1.1.4).
5.1.3.5 Additional timing stations can be positioned along
the length of Section C if rates are desired in small-diameter
tubes.
5.1.3.6 The apparatus as described is suitable for determin-
ing critical diameters up to 1 in. (25.4 mm) (the donor itself
acts as the 1-in. section), but if the minimum diameter for
propagation is greater than 1 in., a larger donor shall be used.
This donor should be 11⁄2 or 2 in. (38.1 or 50.8 mm) in
diameter, as necessary, but otherwise of the same length and
FIG. 1 Diagram of Apparatus
D 2541
2
wall thickness (0.049 in.) (1.24 mm) as the standard donor. The
diameter of the high-explosive booster and detonator holder
shall be scaled up to match, and the constantL/D of 2 shall be
maintained. For instance, if the donor is 2 in. in diameter, the
booster will be at least 2 in. in diameter by 4 in. (102 mm) long.
5.1.4 Assembly No. 4, Trap Testing—In testing detonation
traps, the trap to be tested is attached to either Assembly No. 1
or 3 in place of the small-size tubing being tested for critical
diameter (Section C). Certain configurations can require filling
with liquid before assembly with the donor section. In this
event, the precautions under Section 6 shall be observed.
5.1.5 Booster—The booster charge shall consist of a cylin-
drical pentolite pellet (or equivalent high oxidizers), nominally
21⁄2 in. (64 mm) long by 1 in. (25.4 mm) in diameter, weighing
516 0.3 g with a density of 1.656 0.01 g/cm3, and containing
an axial cavity1⁄4 in. (6.4 mm) in diameter by1⁄2 in. (12.7 mm)
deep for insertion of the electric detonator.
5.1.5.1 Warning—Pentolite is not considered to be a par-
ticularly sensitive explosive, but handle with due respect.
Careless or rough handling can be fatal. Remembered, too, that
practically all high explosives are quite toxic. Handle them
with particular care to avoid spreading the material by contact
of the hands with other parts of the body. Wash hands with soap
and water frequently. Working garments shall be free from
dust-collecting features such as trouser-cuffs, and laundered
frequently.
5.1.6 Detonator—Detonation in the booster pellet shall be
initiated by an electric blasting cap which fits snugly into the
hole in the booster. The cap used with the pentolite booster
shall be a No. 8 commercial cap.
5.1.6.1 Warning—Electric blasting caps contain primary
explosives, which are easily initiated by relatively mild physi-
cal shock. Consequently, every precaution shall be taken by
those who work with them, with particular emphasis on gentle
handling and protection from electrostatic charges. Accumula-
tion of static charges by personnel shall be prevented by use of
all-cotton clothing and special conductive shoes.
5.1.7 Rate-Measurement Apparatus—A 10-MHz counter, or
an oscilloscope (with suitable camera attachment) with a
5-µs/cm sweep frequency, can be used to measurethe time of
propagation between the stations (Note 1). The oscilloscope
has an advantage in that the trace can give some evidence as to
the cause of malfunctions when they occur.
NOTE 1—It can be desirable to use more than two stations or probes,
thus obtaining replicate rate measurements. A circuit diagram for single-
oscilloscope rate measurements is given in Fig. 2.
5.1.7.1 Time-Interval or Counter-Chronograph
Apparatus—The instrument shall be a 10-MHz counter-
chronograph (0.1 µs time base) with a resolution of 0.1 µs in
the range from 0.3 µs to 1 s. The unit shall have an input
sensitivity of 0.2 V rms. The input impedance shall be 1 MV,
direct or a-c coupled, trigger slopes either positive or negative.
Step attenuators shall provide trigger voltage adjustment hav-
ing a range of61, 610, and6100 V.
5.1.7.2 Counter-Chronograph Input Circuitry—Counter-
chronographs currently in use require input voltage pulses with
relatively fast rise times and moderate amplitudes. Both of
these conditions can be met with the simple R-C circuit
described in two forms in Figs. 3 and 4. Since most counter-
chronographs permit polarity and slope selection of the trig-
gering pulses, it is convenient and frequently desirable to
provide maximum pulse isolation by using opposite polarities
for “start” and “stop” triggering pulses from adjacent probes.
The circuits shown schematically in Figs. 3 and 4 were
designed to provide output pulses of opposite polarity when the
inputs are “shorted” through ionization probes or T-1 targets.
With the supply voltage polarities as shown, the output pulse at
J3 is negative when J1 is shorted, while the output pulse at J4 is
positive when J2 is shorted.
5.1.7.3 Oscillograph Circuitry—The circuit for the oscillo-
graph is shown in Fig. 5 and the circuit for the power supply is
All resistors 6 10 percent, 1 W
R1—2000 V
R2—50 V
R3—1 MV
C1—3000 pf, 610 percent, 600 V, dc (C1 may be changed to lengthen or shorten the pulse width)
C2—0.05µ F, 620 percent, 600 V, dc
D—1N34 crystal diode
B—battery 25 to 50 V, dc
S0—trigger station
S1, S2, S3, S4—rate-measuring stations
FIG. 2 Four Channel Mixer Circuit Producing Four Positive Pulses
D 2541
3
shown in Fig. 6. With this apparatus, it is necessary to
synchronize the circuit, and for this a twisted wire (No. 32 B &
S gage (0.202-mm) enameled copper wire is satisfactory) shall
be inserted between the pentolite donor and the acceptor.
5.1.8 Firing Chamber—It is necessary to provide protection
from high-velocity fragments and some means of recovering
the remains, if any, of the acceptor tube. In some instances it is
also desirable to reduce noise from the shot. One solution
consists in using an all-steel chamber in the shape of a simple
maze (Fig. 7). Less elaborate structures have been developed at
other laboratories and function satisfactorily. Another chamber
is illustrated in Fig. 8. The reinforced concrete wall is em-
ployed to protect personnel who conduct the test from a
distance of 200 ft (61 m). This type of enclosure is only
acceptable where three sides of the test site are unoccupied for
a distance of several hundred feet since it is possible that some
fragments may travel this distance. It is recommended that the
side apron of the metal shield be lined with a layer of high
strength steel since this area sustains the most severe damage.
Additional liners can be welded on at the site as needed. Fig.
9 illustrates another possible“ test shelter.”
6. Hazards
6.1 Because of the fairly large quantities of explosives
involved in propagation tests, tests cannot be performed in the
laboratory, but shall be carried out at a suitable firing site.
Before attempting to employ the test, those lacking experience
should be thoroughly educated in the safe handling of explo-
sives. Special safety precautions are recommended wherever
hazards exist that are peculiar to the materials or procedures of
the test. No attempt has been made to treat the general aspects
of safety in explosives handling, since the literature ((1)
through (7))3 amply cover this subject. State and local regula-
tions concerning transportation, storage, and use of explosives
should be consulted andfollowed.
6.2 Before each shot, the firing circuit shall be tested for
continuity with a blasting galvanometer. The shot can be
conveniently fired from the remote control point by means of
a portable blasting machine. The firing line shall consist of
16-gage (1.29-mm) or heavier duplex copper conductor cable.
6.3 It is recommended that the firing line and all instrument
lines have a positive disconnect at the firing position. The
safest practice is to provide anungroundedshunt block for
each of the lines, best located in a box with a hinged cover and
equipped with a lock. Routine inspection of all lines that are
subject to physical damage by fragments or abrasion due to
blasting shall be made and the lines replaced rather than
repaired by splicing and taping. The shunts are removed and
the connections made in the instrument and firing lines after the
blast area is cleared and secured just prior to firing the shot.
7. Preparation of Apparatus
7.1 Since the density of liquids varies with temperature, and
detonation velocity varies with density, it will be necessary,
when determining detonation velocity, to measure and control
the temperature.
NOTE 2—For example, the velocity of nitromethane varies about 3.7
m/s·°C over the range from −20 to 70°C.
7.2 In the determination of critical diameter, temperature
will affect the result since the shock sensitivity generally
increases with temperature. Tests should therefore be made at
21°C within a tolerance of65°C. Temperature control can be
provided by means of a jacket of insulated electrical heating
tape around the sample container(s) in conjunction with a
thermocouple(s). The heating tape can be fabricated tape3⁄16 by
0.003-in. (4.8 by 0.08-mm) Nichrome ribbon and1⁄4-in. (6.4-
mm) glass fiber sleeving.
8. Procedure
8.1 The first operation in setting up a shot consists of
assembling the necessary components for Assembly No. 1, No.
2, No. 3, or No. 4, depending on which measurement is to be
made. This assembly is best carried out at a table or bench in
a charge preparation area near the firing chamber. The con-
tainer shall then be suspended by a wire in the firing chamber,
and when applicable the electrical connections to the target
probes made.Warning—These probes can operate with rela-
tively high potential. It is possible that an electrical fault can
cause a premature initiation. Therefore, the target probe circuit
shall be constructed with the same safety precautions used in
the firing circuit. Pour the liquid under test at the desired
temperature slowly and carefully into the container. In filling
small diameter tubes, entrapped air shall be removed by
opening the pinch clamp at the downstream end. Close the
clamp when bubbles are no longer seen coming out in the
liquid stream.
8.2 The liquid level shall be as high as possible without
risking overflow. Then cover the container with a film of
polyethylene (2 to 5 mils (0.05 to 0.13 mm) in thickness) or
other plastic compatible with the test sample, to separate it
from the pentolite booster and detonator. The finished assem-
bly shall be tested at this time for leaks.
8.3 Prepare the cap by carefully removing it from its
cardboard packing tube and straighten the attached 12-ft
3 The boldface numbers in parentheses refer to the list of references appended to
this test method.
FIG. 3 Bacis R-C Pulse-Forming Circuit
FIG. 4 Practical 2-Channel R-C Pulse-Forming Circuit
Producing a Positive Pulse in One Channel and a Negative Pulse
in the Other Channel
D 2541
4
(3.66-m) leads. If these leads are not long enough for eventual
connection to the firing circuit at a safe distance (preferably out
of line-of-sight) from the firing chamber, extension leads shall
be used. (Electric blasting caps can be ordered with various
lead lengths.) By means of the blasting galvanometer,check
the extension leads for circuit continuity to make sure that they
are shorted out (connected together) at the point where
connection will be made to the firing circuit. After carefully
inserting the cap into a length of heavy steel pipe (12 in. (305
mm) long by 11⁄2 in. (38.1 mm) in inside diameter by 21⁄4 in.
(57.2 mm) in outside diameter, preferably located behind a
shield or around the corner from the operator), make a similar
continuity test to ensure that the wiring within the cap is not
defective. Then connect the cap leads to the extension leads by
tight twisting; take care to make sure that the two splices
cannot short out the cap by making contact with each other or
with the ground. If no extension leads are used, short the cap
leads by twisting together (usually the cap is received this way
from the vendor). Then insert the detonator into the booster and
place the booster-detonator assembly on top of the cap. Hold
the whole assembly in place at the top by a single wrap of
masking tape. Eliminate any air gap or bubble between the
liquid level and the booster.
8.4 Open the firing-circuit terminal box (locked safety box
“A,” Fig. 7), adjacent to the firing chamber. Check the circuit
leading to the control point for continuity, and disconnect the
FIG. 5 Two-Channel Pulse Generator for Propagation Rate Measurements
D 2541
5
extension leads (or cap leads, if no extension leads are used)
from each other, and connect them to the respective firing-
circuit terminals. Then at the control point at the remote end of
the firing circuit, unlock the terminal box (locked safety box
“B,” Fig. 7), energize the velocity probe circuit, if used, and
connect the blasting machine to the terminals there. After
FIG. 6 Power Supply for 2-Channel Pulse Generator
FIG. 7 Firing Site
D 2541
6
sounding whatever warning device is used (siren, horn, buzzer,
etc.), fire the shot by operation of the blasting machine.
8.5 Provision shall be made for adequate ventilation of the
firing chamber, for the gases present after a shot are usually
FIG. 8 Firing Site (Alternative)
FIG. 9 Firing Site (Alternative)
D 2541
7
highly toxic. When such gases have dissipated, the firing
chamber may be entered (or opened) for recovery of the
remains and preparation of the next shot.
9. Interpretation of Results
9.1 In every case, the length of tubing containing the donor
section, that is, the forerunning section, should be completely
destroyed and reduced to fine fragments.
9.2 In the critical-diameter tests (Assembly No. 1 or 3), the
tubing under test will be completely fragmented its entire
length if it is greater than critical diameter or fragmented for
only a short distance if it is less than critical diameter.
NOTE 3—The critical diameter is reported as lying between the incre-
mental diameters experimentally employed.
9.3 In detonation trap tests (Assembly No. 4) the tubing will
be similarly disintegrated for a length corresponding to the
persistence of high-velocity detonation. Bursting or splitting of
the tube, although having possible significance as regards
safety of a particular system, is not a criterion of stable
high-velocity detonation.
9.4 A sufficient number of trials should be made to establish
whether reproducibility has been obtained.
10. Report
10.1 Detonation velocities are calculated directly from mea-
sured time lapses over the distance between stations (Assembly
No. 2 or 3). They should be 1000 m/s or more. Generally,
high-velocity detonations are characterized by measured rates
between 3000 and 8500 m/s.
10.2 In reporting the results, the number of shots should be
stated and, where possible, some mathematical expression of
variation should be given, such as average deviation or
standard deviation.
10.3 Any deviations from the recommended procedures
should be reported with the test results.
11. Precision and Bias
11.1 Due to the complex nature of this test method and the
expensive equipment involved in the initial setup of the
apparatus, there is not a sufficient number of volunteers to
permit a cooperative laboratory program for determining the
precision and bias of this test method. If the necessary
volunteers can be obtained a program will be undertaken at a
later date.
12. Keywords
12.1 critical diameter; detonation velocity; liquid monopro-
pellants; monopropellants; propellants
D 2541
8
REFERENCES
(1) “Blaster’s Handbook,” 14th ed., 1958, Explosives Dept., E. I. duPont
de Nemours and Co., Wilmington, Del. 19898.
(2) Ordinance Safety Manual(ORD M7-224), Ordnance Corps, Dept. of
the Army, 1951, as revised.
(3) “Stray Currents in Electric Blasting” (Data Sheet D-MIN. 2), National
Safety Council, 425 N. Michigan Ave., Chicago, Ill. 60611 (1950).
(4) “Blasting from Electric Power Circuits” (Data Sheet D-MIN. 10),
National Safety Council, 425 N. Michigan Ave., Chicago, Ill. 60611
(1950).
(5) Sax, N. I., “Dangerous Properties of Industrial Materials,” Reinhold
Publishing Corp., New York, N. Y., 1968.
(6) “Motor Carriers’ Explosives and Dangerous Articles Tariff No. 10”
(I.C.C. Regulations for Transportation of Explosives and Other Dan-
gerous Articles by Motor, Rail and Water), American Trucking
Association, Inc., November 1958, as amended.
(7) “Liquid Propellant Handling, Storage, and Transportation,”Chemical
Rocket/Propellant Hazards, JANNAF Hazards Working Group, CPIA
Publication No. 194, Chemical Propulsion Information Agency, Johns
Hopkins University, Applied Physics Laboratory, Silver Spring, Md.,
Vol III, May 1970.
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, 100 Barr Harbor Drive, West Conshohocken, PA 19428.
This standard is copyrighted by ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States. Individual
reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585
(phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (http://www.astm.org).
D 2541
9
Designation: D 3039/D 3039M – 00
Standard Test Method for
Tensile Properties of Polymer Matrix Composite Materials 1
This standard is issued under the fixed designation D 3039/D 3039M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method determines the in-plane tensile prop-
erties of polymer matrix composite materials reinforced by
high-modulus fibers. The composite material forms are limited
to continuous fiber or discontinuous fiber-reinforced compos-
ites in which the laminate is balanced and symmetric with
respect to the test direction.
1.2 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health