RADIOSS Tutorials and Examples

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Table of Contents 
Tutorials and Examples ......................................................................................................................................... 3 
Tutorials ............................................................................................................................................................3 
Accessing the Model Files .............................................................................................................................. 4 
Introductory Tutorials ................................................................................................................................... 5 
Examples....................................................................................................................................................... 272 
List of Examples......................................................................................................................................... 273 
Example 1 - Twisted Beam ......................................................................................................................... 281 
Example 2 - Snap-thru Roof ....................................................................................................................... 287 
Example 3 - S-beam Crash ......................................................................................................................... 301 
Example 4 - Airbag .................................................................................................................................... 317 
Example 5 - Beam Frame ........................................................................................................................... 328 
Example 6 - Fuel Tank ................................................................................................................................ 335 
Example 7 - Pendulums ............................................................................................................................. 353 
Example 8 - Hopkinson Bar ........................................................................................................................ 371 
Example 9 - Billiards (pool) ........................................................................................................................ 390 
Example 10 - Bending ................................................................................................................................ 417 
Example 11 - Tensile Test .......................................................................................................................... 426 
Example 12 - Jumping Bicycle .................................................................................................................... 465 
Example 13 - Shock Tube ........................................................................................................................... 486 
Example 14 - Truck with Flexible Body ....................................................................................................... 506 
Example 15 - Gears .................................................................................................................................... 531 
Example 16 - Dummy Positioning .............................................................................................................. 540 
Example 17 - Box Beam ............................................................................................................................. 573 
Example 18 - Square Plate ......................................................................................................................... 640 
Example 19 - Wave Propagation ................................................................................................................ 671 
Example 20 - Cube ..................................................................................................................................... 685 
Example 21 - Cam ...................................................................................................................................... 691 
Example 22 - Ditching using SPH and ALE (Mono-Domain and Multi-Domain) ............................................ 709 
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Example 23 - Brake .................................................................................................................................... 732 
Example 24 - Laminating ........................................................................................................................... 741 
Example 25 - Spring-back .......................................................................................................................... 752 
Example 26 - Ruptured Plate ..................................................................................................................... 771 
Example 27 - Football (Soccer) Shots ......................................................................................................... 782 
Example 37 - Analytical Beam .................................................................................................................... 789 
Example 39 - Biomedical Valve .................................................................................................................. 801 
Example 42 - Rubber Ring: Crush and Slide ................................................................................................ 810 
Example 43 - Perfect Gas Modeling with Polynomial EOS .......................................................................... 820 
Example 44 - Blow Molding with AMS ....................................................................................................... 839 
Example 45 - Multi-Domain ....................................................................................................................... 846 
Example 46 - TNT Cylinder Expansion Test ................................................................................................. 855 
Example 47 - Concrete Validation .............................................................................................................. 876 
Example 48 - Solid Spotweld ...................................................................................................................... 897 
Example 49 - Bird Strike on Windshield ..................................................................................................... 905 
Example 50 - INIVOL and Fluid Structure Interaction (Drop Container) ...................................................... 914 
Example 51 - Optimization in RADIOSS for B-Pillar (Thickness optimization) .............................................. 921 
Example 52 - Creep and Stress Relaxation ................................................................................................. 929 
Example 53 - Thermal Analysis .................................................................................................................. 935 
 
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Tutorials and Examples 
 
Tutorials 
 
Below is a list of the RADIOSS tutorials available. 
 Introductory Tutorials 
RD-0010: Running RADIOSS from HyperMesh 
RD-0020: Running RADIOSS at the Command Line 
 Large Displacement Finite Element Analysis - HyperCrash 
RD-3000: Tensile Test Setup using HyperCrash 
RD-3030: Buckling of a Tube using Half Tube Mesh 
RD-3050: Simplified Car Pole Impact using HyperCrash 
RD-3060: Three Point Bending with HyperCrash 
RD-3150: Seat Model with Dummy using HyperCrash 
RD-3160: Setting up Multi-Domain Analysis using HyperCrash 
HF-5000: Using Results Mapper in HyperCrash 
 Large Displacement Finite Element Analysis - HyperMesh 
RD-3500: Tensile Test Setup using HyperMesh 
RD-3510: Cantilever Beam with Bolt Pretension 
RD-3520: Pre-Processing for Pipes Impact using RADIOSS 
RD-3530: Buckling of a Tube using Half Tube Mesh 
RD-3540: Front Impact Bumper Model using HyperMesh 
RD-3550: Simplified Car Pole Impact 
RD-3560: Bottle Drop 
RD-3580: Boat Ditching (with and withoutBoundary) 
RD-3590: Fluid Flow through a Rubber Clapper Valve 
RD-3595: Three Point Bending with HyperMesh 
RD-3597: Cell Phone Drop Test using HyperMesh 
RD-3599: Gasket with HyperMesh 
 
 
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Accessing the Model Files 
Required model files of the models you build in the tutorials are available online. 
1. To access model files, visit Altair Connect or the Altair Client Center. 
A user ID and password are required to access the model files. Follow the instructions at the 
website to obtain login credentials. 
2. Select the required file package and download it onto your system. 
Note that the files may require unzipping before proceeding with the tutorials. When extracting 
zipped files, preserve any directory structure included in the file package. 
 
 
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Introductory Tutorials 
 
RD-0010: Running RADIOSS from HyperMesh 
This tutorial demonstrates how to launch a RADIOSS job from within HyperMesh. A HyperMesh 
database containing a fully defined RADIOSS finite element model is retrieved and a RADIOSS job is 
launched from the RADIOSS panel in HyperMesh. 
 
Exercise 
 
 
Step 1: Load the User Profile 
1. Launch HyperMesh. The User Profiles dialog appears upon start-up by default. 
2. If the User Profiles dialog is not visible, select Preferences from the toolbar and choose User 
Profiles. 
3. Under Application:, select RADIOSS. 
4. Click OK. This loads the appropriate User Profile. It includes the appropriate template, macro 
menu, and import reader. It simplifies the menu systems to give access to only the functionality 
of HyperMesh that is necessary. 
Step 2: Retrieve the HyperMesh database 
1. From the File menu on the toolbar, select Open. An Open file browser window opens. 
2. Select the Radioss_Sample_Run.hm file you saved to your working directory from the 
radioss.zip file. Refer to Accessing the Model Files. 
3. Click Open. The Radioss_Sample_Run.hm database is loaded into the current HyperMesh 
session, replacing any existing data. 
Step 3: Launch the RADIOSS job 
1. From the Analysis page, select the RADIOSS panel. 
2. Click save as. A Save file browser window opens. 
3. Select the directory where you would like to write the model file and enter the file name, 
Radioss_Sample_Run.rad, in the File name: field. The .rad file name extension is the 
suggested extension for RADIOSS input decks. 
4. Click Save. The name and location of the Radioss_Sample_Run.rad file now displays in the 
input file: field. 
5. Set the memory toggle, located in the center of the panel, to memory default. 
6. Set the run options toggle, located on the left side of the panel, to analysis. 
7. Set the export options: toggle, underneath the run options switch, to all. 
 
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8. Click RADIOSS. 
This exports the input file and launches the job. If the job is successful, new results files can be 
seen in the directory where the model file was written. The Radioss_Sample_Run.out file is a 
good place to look for error messages that will help to debug the input deck if any errors are 
present. 
The default files written to your directory are: 
Radioss_Sample_Run.html HTML report of the analysis, giving a summary of the 
problem formulation and the analysis results. 
Radioss_Sample_Run.out ASCII output file containing specific information on the 
file set up, the set up of your optimization problem, 
estimate for the amount of RAM and disk space 
required for the run, information for each optimization 
iteration, and compute time information. Review this 
file for warnings and errors. 
Radioss_Sample_Run.res HyperMesh binary results file. 
Radioss_Sample_Run.stat Summary of analysis process, providing CPU 
information for each step during analysis process. 
Radioss_Sample_Run.h3d HyperView binary result file. 
Step 4: Post-process the RADIOSS job 
While still in HyperMesh, you can launch HyperView after the job has finished from the RADIOSS 
panel by clicking HyperView. HyperView will open and automatically load the H3D file from the 
RADIOSS job for post-processing. 
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RD-0020: Running RADIOSS at the Command Line 
The tutorial Running RADIOSS from HyperMesh demonstrates how RADIOSS could be launched 
from within HyperMesh. RADIOSS also can be run at the command line (UNIX or MSDOS). This 
tutorial assumes you already have the running file, Radioss_Sample_Run.rad, in either your UNIX 
or MSDOS directory. This tutorial also assumes you know the location of the solver script. 
In this tutorial, $HWSDIR describes the directory containing the RADIOSS executable. On UNIX 
machines, the script is normally located in the HyperWorks installation directory under 
<install_directory>/scripts/. On Windows, it is normally located in the HyperWorks installation 
directory under <install_directory>/hwsolvers/scripts/. 
Running RADIOSS from the Command Line (UNIX or MSDOS). 
To run RADIOSS from the command prompt, enter: 
$HWSDIR/<solver_name> Radioss_Sample_Run.rad 
 
To check the current version of RADIOSS at the command prompt, enter: 
$HWSDIR/<solver_name> -version 
 
To execute a check run to validate your input deck and determine how much RAM and 
disk space is necessary for the run, at the command prompt, enter: 
$HWSDIR/<solver_name> Radioss_Sample_Run.rad -check 
Information regarding memory requirements is written to the file Radioss_Sample_Run.out. 
Refer to the Running RADIOSS section of the RADIOSS User's Guide for more detailed information. 
 
 
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Large Displacement Finite Element Analysis 
HyperCrash 
RD-3000: Tensile Test Setup using HyperCrash 
This tutorial demonstrates how to simulate a uniaxial tensile test using a quarter size mesh with 
symmetric boundary conditions. 
 
The model is reduced to one-quarter of the total mesh with symmetric boundary conditions to 
simulate the presence of the rest of the part. 
 
Model Description 
 UNITS: Length (mm), Time (ms), Mass (kg), Force (kN) and Stress (GPa) 
 Simulation time Rootname_0001.rad [0 – 10.] 
 Boundary Conditions: 
o The 3 upper right nodes (TX, RY, and RZ) 
o A symmetry boundary condition on all bottom nodes (TY, RX, and RZ) 
 At the left side is applied a constant velocity = 1 mm/ms on -X direction. 
 Tensile test object dimensions = 11 x 100 with a uniform thickness = 1.7 mm 
Johnson-Cook Elastic Plastic Material /MAT/PLAS_JOHNS (Aluminum 6063 T7) 
[Rho_I] Initial density = 2.7e-6 Kg/mm3 
[E] Young’s modulus = 60.4 GPa 
[nu] Poisson’s ratio = 0.33 
[a] Yield stress = 0.09026 GPa 
[b] Hardening parameter = 0.22313 GPa 
[n] Hardening exponent = 0.374618 
[EPS_max] Failure plastic strain = 0.75 
[SIG_max] Maximum stress = 0.175 GPa 
Input file for this tutorial: TENSILE_0000.rad 
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Exercise 
 
 
Step 1: Import the mesh 
1. Open HyperCrash and set the User profile: to RADIOSS V14 and the Unit system: to kN 
mm ms kg. 
1. Click Run. 
2. From the menu bar, select File > Import > RADIOSS. 
3. In the Select RADIOSS File(s) dialog, select TENSILE_0000.rad. 
4. Click OK. 
Setting up the Problem in HyperCrash 
 
 
Step 2: Create and assign a material 
1. From the menu bar, select Model > Material. 
2. Right-click in the material list and select Create New > Elasto-plastic > Johnson-Cook (2). 
3. For Title, enter Aluminum. Enter all the material data listed above. 
4. In the bottom of the material window, right-click in the Support entrybox and select Include 
picked parts icon . 
 
5. Select the part in the graphics area (left-click). 
6. Right-click to validate the selection. 
7. Press ENTER or click Save > Close. 
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Step 3: Create and assign a property 
1. From the menu bar, select Model > Property. 
2. Right-click in the property list and select Create New > Surface > Shell (1). 
3. For Title, enter Pshell. 
4. For Shell Thickness, enter 1.7. 
5. In the bottom of the property window, right-click in the Support entry box and select Include 
picked parts icon . 
6. Select the part in the graphics area. 
7. Right-click to validate the selection. 
8. Click Save > Close. 
Step 4: Define boundary conditions representing symmetry 
1. From the menu bar, select LoadCase > Boundary Condition. 
2. Right-click in the display list area and select Create New. 
3. For Name, enter constraint1 and click Save. Expand the folders Translation and Rotation. 
4. Right-click in the Support entry box, click Select in graphics and select Add/Remove nodes 
by picking selection icon to select the nodes in the Graphic Window, as shown in the figure 
below: 
 
5. Click Yes in the Dialog menu bar to validate your selection. 
6. To constrain the nodes, toggle Tx, Ry and Rz and click Save. 
7. Repeat the same operations to create constraint2, as shown in the figure below: 
 
8. Toggle Tx, Ty, Tz, Rx, Ry and Rz, and click Save. 
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9. Repeat the same operations to create constraint3, as shown in the figure below. Press SHIFT, 
left-click and hold the mouse to draw a box to select the nodes. 
 
10. Toggle Ty, Rx, and Rz. 
11. Click Save > Close. 
Step 5: Define the imposed velocity 
1. From the menu bar, select LoadCase > Imposed > Imposed Velocity. 
2. Right-click in the display list area and select Create New. 
3. Set the Title to imposed_velocity. 
4. Right-click in the entry box for Time function and select Define Function. A Function 
Window opens up. 
5. For Function name, enter FUNC_VEL. 
6. Enter the first point (0,1) and click Validate. 
7. Enter the second point (1e30,1) and click Validate. 
8. Click Save in the dialog. 
9. Right-click in the Support entry box, click Select in graphics and select the Add nodes by 
box selection icon , to select the nodes in the graphic window, as shown in the figure below: 
 
10. Go to the Properties tab and enter a Y-Scale factor = -1. 
11. Ensure Direction of the imposed velocity is set to X (translation). 
12. Click Save > Close. 
Step 6: Select a node for time history output 
1. From the menu bar, select Data History > Time History. 
2. In the list display area, right-click and select Create New > TH of nodes. 
3. Enter the title Node_79. 
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4. Click Add Row to add a new row. With that row selected, scroll down to the input section 
and enter NODid as 79 and press ENTER. 
As an alternative, use the Pick button to select a node in the graphic window. 
5. Click Save > Close. 
Step 7: Create Control Cards, Export the Starter and Engine files 
1. From the menu bar, select Model > Control Card: 
 
2. Enter the values for the Control Cards, as shown in the images below, saving after every step: 
 
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3. Click File > Export > RADIOSS to export the solver file. 
4. In the Write Block Format 140 RADIOSS File window that opens, navigate to your desired 
run directory and create a new folder named TENSILE_TEST. 
5. For filename, enter TENSILE and click OK. 
6. Leave the Header window empty and click on Save Model. The file TENSILE_0000.rad is 
written. 
The model is now ready to run through the Starter and the Engine. It will produce the result files 
TENSILEA* for animation in HyperView and TENSILE01 for time history plotting in HyperGraph. 
RADIOSS Computing 
 
 
Step 8: Run RADIOSS Starter and RADIOSS Engine 
1. Launch RADIOSS from the Start menu. A HyperWorks Solver Run Manager window appears. 
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2. In the Input file field, select TENSILE_0000.rad. from the folder you created. 
3. Click Run. 
The HyperWorks Solver View window is opened. The RADIOSS Starter will run and on completion 
the RADIOSS Engine will automatically run. 
Step 9: Review the listing files for this run and verify the results 
1. See if there are any warnings or errors in the .out files. 
2. Using HyperView, plot the displacement and strain contour. 
Exercise Expected Results 
 
 
 
Total Displacement Contour (mm) 
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Plastic Strain Contour 
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RD-3030: Buckling of a Tube using Half Tube Mesh 
Simulate buckling of a tube using half tube mesh with symmetric boundary conditions. 
The figure illustrates the structural model used for this tutorial: a half tube with a rectangular 
section (38.1 x 25.4 mm) and length of 203 mm. 
 
Model 
Model Description 
 
 
 UNITS: Length (mm), Time (ms), Mass (kg), Force (kN) and Stress (GPa) 
 Simulation time: Engine [0 – 10 ms] 
 The tube thickness is 0.914 mm. 
 An imposed velocity of 13.3 mm/ms (~30 MPH) is applied to the right end of the tube 
 Elasto plastic material using Johnson-Cook law /MAT/PLAS_JOHNS (STEEL). 
[Rho_Initial] Initial density = 7.85e-6 Kg/mm3 
[E] Young’s modulus = 210 GPa 
[nu] Poisson coefficient = 0.3 
[a] Yield Stress = 0.206 GPa 
[b] Hardening Parameter = 0.450 GPa 
[n] Hardening Exponent = 0.5 
File needed to complete this exercise: BOXTUBE_0000.rad 
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Exercise 
 
 
Step 1: Import the mesh 
1. Open HyperCrash and set the User profile: to RADIOSS V14 and the Unit system: to kN 
mm ms kg. 
2. Set User interface style as New. 
3. Set the working directory to <install_directory>/tutorials/hwsolvers/radioss/. 
4. Click Run. 
5. Click File > Import > RADIOSS. 
6. In the input window, select BOXTUBE_0000.rad. 
7. Click OK. 
Step 2: Create and assign a material 
1. Click Model > Material. 
2. In the window, right-click and choose Create New > Elasto-plastic > Johnson-Cook (2). 
 
3. For Title, enter Steel. 
Enter all the material data, as shown in the following figure. 
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4. Right-click in Support entry box and click Select in graphics and select Include picked 
parts and select boxtube in the graphics area. 
5. Press ENTER, or click Yes in the lower right corner. 
6. Click Save > Close. 
Step 3: Create and assign a property 
1. Click Model > Property. 
2. In the window, right-click and select Create New > Surface > Shell (1). 
 
3. For Title, enter Pshell. 
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4. For Shell thickness, enter 0.914. 
 
5. Right-click in the Support entry box and click Select in graphics and select Include picked 
parts and select boxtube in the graphics area. 
6. Press ENTER or click Yes in the lower right corner. 
7. Click Save > Close. 
Step 4: Define Rigid Body 
1. Click Mesh Editing > Rigid Body. Right-click in the display list area and selectCreate New. 
2. Right-click in the graphic area and select Add nodes by box selection icon to select the 
nodes in the graphic window, as shown below: 
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3. Press ENTER or click Save to validate. 
 
Note: For the remainder of the tutorial, you need to have the ID of 
the master node of the rigid body. 
4. Click Show Node Info icon in the toolbar, and select the rigid body master node in the 
graphic window. The Node ID appears in the message window (node ID: 803). 
5. Click Cancel in the lower right corner to exit the picking loop. 
6. Click Close. 
Step 5: Define boundary condition applied on rigid body 
1. Click LoadCase > Boundary Condition. 
2. Right-click in the display list area and select Create New. 
3. In the Boundary condition field, enter the name Rigid_BC. 
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4. In the Node by Id field, enter 803, then click Ok. 
5. To constrain the nodes, toggle the buttons in Tx, Ty, Rx, Ry and Rz. 
 
6. Click Save. 
Step 6: Define boundary condition representing symmetry 
1. In the Boundary condition display list area, select Create New. Name the new constraint set 
symmetry. 
2. Right-click in the Support entry box and click Select in graphics and select Add nodes by 
box selection icon to select the nodes in the graphic window, as shown below: 
 
3. Right-click to validate. 
4. Toggle the buttons Tx, Ry and Rz. 
5. Click Save > Close. 
Step 7: Define the imposed velocity 
1. Click LoadCase > Imposed Velocity. Right-click in the display list area and select Create 
New. 
2. For Title, enter VELOCITY. 
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3. Right-click in the Time function parameter entry box and select Define New. A Function 
Window opens. 
4. For the function name, enter FUNC_VEL. 
5. Enter the first point (0, 13.3) and click Validate. 
6. Enter the second point (1e30, 13.3) and click Validate. 
7. Click Save in the Function Window to accept the function. 
8. Expand the Advanced selector at the bottom and in the Node by Id field, enter 803 and click 
Ok, (or toggle Add RB master nodes). 
9. Go to the Properties tab and enter a Y-Scale factor = -1. 
10. Set the direction of the imposed velocity to Z (translation). 
11. Click Save > Close. 
 
Step 8: Define a Rigid Wall 
1. Click LoadCase > Rigid Wall > Create. 
2. For the Select RWALL, select Infinite Plane. 
3. For Title, enter RIGID WALL. 
4. Enter the following values: M0: X= 0, Y= 38.1, Z= -204. M1: X= 0, Y= 38.1, Z= 1. 
5. In the Distance to search slave nodes field, enter 20. 
6. Toggle See option. 
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7. Click See to visualize it in the graphic window. 
 
8. Click Save > Close. 
Step 9: Create a self contact for the tube 
1. Click LoadCase > Contact Interface. 
2. Right-click in the Contact Interface list and select Create New > Multi usage (Type 7). 
3. Toggle Self impact. 
 
4. Right-click in the graphic area, and select Include picked parts icon and select the part in 
the graphic window. 
5. Click Yes in the lower right corner of the main window to validate. 
6. For Title, enter the name Contact. 
7. Set Scale factor for stiffness as 1. 
8. Set Min. gap for impact active to 0.900. 
9. Set Coulomb friction to 0.200. 
10. Click Save > Close. 
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Step 10: Export the model 
1. Under the Model menu, select Control Card. 
2. Check Control Card to activate it. 
Note: Make sure to save it before moving to the next Control Card. 
 
 
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3. Click File > Export > RADIOSS. 
4. In the Write Block Format 140 RADIOSS File window that opens up, enter the name BOXTUBE 
and click OK. 
5. Leave the Header of RADIOSS File window empty and click Save Model. 
The Starter file BOXTUBE_0000.rad is written. 
The model is now ready to run through the Starter and the Engine. 
Step 11: Open RADIOSS from Windows Start menu 
 
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Step 12: Review the listing files for this run and verify on the results 
1. Using HyperView, plot the displacement and strain contour at 10 ms. 
Exercise Expected Results 
 
 
 
Total Displacement (mm) and Plastic Strain (Mid Layer and Average) 
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RD-3050: Simplified Car Pole Impact in HyperCrash 
To simulate frontal pole test with a simplified full car. 
 
Model Description 
 
 
 UNITS: Length (mm), Time (s), Mass (ton), Force (N) and Stress (MPa) 
 Simulation time: Engine file (_0001.rad) [0 – 0.06 ms] 
 An initial velocity of 15600 mm/s is applied on the car model to impact a rigid pole of radius 
250 mm. 
 Elasto-plastic Material /MAT/PLAS_JOHNS (WINDSHIELD) 
[Rho_Initial] Initial Density = 2.5x10-9 ton/mm3 
[E] Young's Modulus = 76000 MPa 
[nu] Poisson’s Ratio = 0.3 
[ 0] Yield Stress = 192 MPa 
[K] Hardening Parameter = 220 MPa 
[n] Hardening Exponent = 0.32 
 Elasto-plastic Material /MAT/PLAS_JOHNS (STEEL) 
[Rho_Initial] Initial Density = 7.9x10-9 ton/mm3 
[E] Young's Modulus = 210000 MPa 
[nu] Poisson’s Ratio = 0.3 
[ 0] Yield Stress = 200 MPa 
[K] Hardening Parameter = 450 MPa 
[n] Hardening Exponent = 0.5 
[SIG_max] Maximum Stress = 425 MPa 
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 Elasto-plastic Material /MAT/PLAS_JOHNS (RUBBER) 
[Rho_Initial] Initial Density = 2x10-9 ton/mm3 
[E] Young's Modulus = 200 MPa 
[nu] Poisson’s Ratio = 0.49 
[ 0] Yield Stress = 1e
30 MPa 
[n] Hardening Exponent = 1 
 
Exercise 
 
 
Step 1: Retrieve the HyperMesh file 
1. Open HyperCrash and set the User profile: to RADIOSS V14 and the Unit system: to kN 
mm ms. kg. 
2. Set User Interface style as New. 
3. Set the working directory to <install_directory>/tutorials/hwsolvers/radioss. 
4. Click Run. 
5. Click File > Import > Nastran. 
6. In the input window, select full_car.nas. 
7. Click OK. 
Step 2: Create WINDSHIELD material and assign to car windows 
1. Click Model > Material. 
2. In the Material list, right-click and select Create New > Elasto-Plastic > Johnson-Cook (2). 
3. For Title, enter WINDSHIELD. 
4. Enter all the material data, as shown in the image below. 
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5. Click the Tree tab and select PSHELL3 and PSHELL16 in the tree. 
6. Click to show only these parts. 
7. Click the Material tab. 
8. Right-click in the Support entry box and click Selected Parts of Tree . This icon allows 
adding the part selected in the tree to the selection. The selected parts will be highlighted in the 
graphic area. 
9. Click Save. 
Step 3: Create RUBBER material and assign to car tires 
1. In the Material list, right-click and select Create New > Elasto-Plastic > Johnson-Cook (2). 
2. For Title, enter RUBBER. Enter all the material data, as shown in the image below. 
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3. Click the Tree tab and select PSHELL20 to PSHELL23 in the tree. 
4. Click to show only these parts. 
5. Click the Material tab. 
6. Right-click in the Support entry box and click Selected Parts of Tree . The selected parts 
will be highlighted in the graphic area. 
7. Click Save. 
Step 4: Create STEEL material and assign to all other parts 
1. In the Material list, right-click and select CreateNew > Elasto-Plastic > Johnson-Cook (2). 
2. For Title, enter STEEL. 
3. Enter all the material data, as shown in the image below. 
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4. Click the Tree tab and select PSHELL3, PSHELL16 and PSHELL20 to PSHELL23 in the tree. 
5. Click to invert the tree selection. 
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6. Click to show all the parts except the ones made with glass and rubber. 
 
7. Click the Material tab. 
8. Right-click in the Support entry box and click Selected Parts of Tree . The selected parts 
will be highlighted in the graphic area. 
9. Click Save > Close. 
Step 5: Create a rigid wall to represent the ground 
1. Click LoadCase > Rigid Wall > Create. 
2. Under Rigid wall name > Select RWALL type, select Infinite Plane. 
3. Enter the rigid wall name, Ground. 
4. Enter the following values for M0 and M1: 
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5. In the Selection tab, set the Distance to search for slave nodes to 300. 
6. Click See at the bottom of the panel to display the rigid wall. 
7. Click Save. 
Step 6: Create Pole Rigid Walls 
1. Under Rigid wall name > Select RWALL type, select Cylinder. 
2. Enter the rigid wall name, Pole. 
3. Enter the following values for M0 and M1: 
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4. Set the Diameter to 500. 
5. Set the Distance to search for slave nodes to 1500. 
6. Click See at the bottom of the panel to display the rigid cylinder. 
7. Click Save. 
8. Click Close to close the Rigid Walls panel. 
Step 7: Define interface with the whole car 
1. Click LoadCase > Contact Interface. 
2. In the window right-click and select Create New > Multi usage (Type 7). 
3. Select the Self Impact box. 
4. In the Title field, enter CAR_CAR. 
5. Set [Istf] Stiffness definition to 2: (K=(Km+Ks)/2. 
6. For [Gapmin] Min. gap for impact activ., enter 0.7. 
7. For [Fric] Coulomb friction, enter 0.2. 
8. Set [Iform] Friction penalty formulation to 2: (Stiffness). 
9. In the Model Display toolbar, click Display All to display the entire model. 
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10. Click in the [Mast_id] Master field, move the cursor to the graphical window and right-click. 
The menu shown in the image below should appear. Choose the option Add selected parts by 
box and use the mouse to drag a box to select the entire car in the graphic window. 
 
11. Click Save. 
Step 8: Create an interface between engine and radiator 
1. Right-click in the Contact list and select Create New > Multi usage (Type 7). 
2. Check Create symmetric interface at saving box. 
3. In the Title field, enter ENGINE_RADIATOR. 
4. For [Istf] Stiffness definition, set to 2 (K=(Km+Ks)/2. 
5. For [Gapmin] Min. gap for impact active, enter 0.7. 
6. For [Fric] Coulomb friction, enter 0.2. 
7. For [Iform] Friction penalty formulation, set to 2 [Stiffness]. 
8. In the Tree tab, highlight the part PSHELL28 (Radiator) and PSHELL30 (Engine) and 
Isolate them. 
9. In the Contact Interface tab, click in the [Slav_id] Slave nodes field, move the cursor to the 
graphic window, right-click and select Include picked Part. Select the Radiator (PSHELL28). 
10. In the Contact Interface tab, click in the [Mast_id] Master Surface field, move the cursor to 
the graphic window, right-click and select Include picked Part. Select the Engine 
(PSHELL30). 
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11. Click Save. 
12. Click Close to close the Contact tab. 
An additional symmetric interface is created. 
Step 9: Define Initial Velocities 
1. Click LoadCase > Initial Velocity. 
2. In the Velocity list, right-click and select Create New. 
3. In the Title field, enter 35MPH. 
4. In the Tree window, highlight FULL_CAR. 
5. In the [Vx] field, enter 15600. 
6. In the Initial Velocity tab and click in the [Gnod_id] Support field. Move the cursor to the 
graphic window, right-click and select Add selected parts of tree . 
7. Click Save > Close. 
Step 10: Define Time History Nodes 
1. Click Data History > Time History. 
2. In the Time History list, right-click and select Create New > TH of nodes. 
3. For Title, enter RAIL. 
4. In the Tree tab, select PSHELL19. 
5. Click Isolate Tree Selections . 
6. Go back to the Time History panel and click Add/Remove nodes by picking selection in 
the second table. 
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7. Select six nodes on the rails, for example as shown in the following image: 
 
7. Click Yes in the lower right corner or right-click in the graphic window to exit the selection. 
8. Click Save > Close. 
Step 11: Export the model 
1. Create the Engine file: From the menu bar, select Model > Control Card. 
2. Check the Control Cards, as shown in the images below. 
Note: Make sure to save all control card before editing the next. 
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3. Under the Quality menu, click Model Checker to check the quality, then check All Solver 
Contact interfaces, remove all the initial penetrations in the model. 
4. Under the Mesh Editing menu, click Clean, then clean the model before exporting. 
5. Click File > Export > RADIOSS, enter FULLCAR and click OK. 
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6. Leave the Header of RADIOSS File window empty and click Save Model. The Starter file 
FULLCAR_0000.rad is written. 
Step 12: Open RADIOSS from Windows Start menu 
 
Step 13: Select the Starter file FULLCAR_0000.rad as Input file and Run 
the model 
Exercise Expected Results 
 
 
 
Final deformation and energy balance plot 
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RD-3060: Three Point Bending with HyperCrash 
This tutorial demonstrates how to set up a 3-point bending model with symmetric boundary 
conditions in Y direction (across the XZ plane). 
 
Model Description 
 
 
 UNITS: Length (mm), Time (s), Mass (ton), Force (N) and Stress (MPa) 
 Simulation time: in Rootname_0001.rad [0 – 7.0E-2s] 
 Only one half of the model is modeled because it is symmetric. 
 The supports are totally fixed. An imposed velocity of 1000 mm/s is applied on the Impactor 
in the (–Z) direction 
 Model size = 370mm x 46.5mm x 159mm 
 Honeycomb Material /MAT/LAW28: HONEYCOMB 
[Rho_I] Initial density = 3.0e-10 ton/mm3 
[E11], [E22] and [E33] Young’s modulus (Eij) = 200 MPa 
[G11], [G22] and [G33] Shear modulus (Gij) = 150 MPa 
 Elasto-Plastic Material /MAT/LAW36: Inner, Outer and Flat 
[Rho_I] Initial density = 7.85-9 ton/mm3 
[E] Young’s modulus = 210000 MPa 
[nu] Poisson's ratio = 0.29 

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 Strain Curve: 
 0 1 2 3 4 5 6 7 8 9 
STRAIN 0 0.010 0.013 0.015 0.020 0.025 0.030 0.035 0.040 0.045 
STRESS8E- 300 310 320 330 340 350 360 370 380 400 
 Elastic Material /MAT/PLAS_JOHNS: Impactor 
[Rho_I] Initial density = 8e-9 ton/mm3 
[E] Young’s modulus = 208000 MPa 
[nu] Poisson's ratio = 0.29 
Step 1: Import the RADIOSS mesh model 
1. Open HyperCrash 2017. 
2. For User profile:, select RADIOSS V14. 
3. For Unit system:, select N mm s T. 
4. Select User interface style as New. 
5. Click Run. 
6. Click File > Import > RADIOSS. 
7. In the input window, navigate to the correct directory and selectBENDING_0000.rad. 
8. Click OK. 
Step 2: Create and assign a material 
1. Click Model > Material. 
2. In the Window, right-click and select Create New > Elastic > Linear elastic (1) as shown 
below: 
 
3. For Title, enter Rigid Material. 
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4. Enter all the material data, as shown in the following image. 
 
5. Right-click in the entry box Support and click Include picked parts and select the parts 
Impactor and Support in the graphics area. 
6. Click Yes in the lower right corner to validate. 
7. Press ENTER or click Save to validate. 
Step 3: Create and assign a material for Inner, Outer, and Flat parts 
1. In the Window, right-click and select Create New > Elasto-plastic > Piecewise linear (36). 
2. For Title, enter Shell Material. 
3. Enter all the material data, as shown in the following image: 
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4. Open the Strain rate folder and click to add a row. 
5. Right-click in Yield stress function field and click Select in Model to select an existing 
function in the model. 
 
6. In the Function file window, select the function with an ID of 2, then click OK to import the 
curve. The function can be edited, as shown in the image below. 
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7. Click the Tree tab and select the parts Inner, Outer, and Flat on the tree. 
8. Click to isolate this part. 
9. Click the Material tab. 
10. Right-click the entry box Support, and click Include picked parts in the graphic area, and 
select the parts Inner, Outer and Flat in the graphics area as shown in the following image. 
 
11. Click Yes in the lower right corner to validate. 
12. Press ENTER or click Save to validate. 
Step 4: Create and assign a new material for HCFoam 
1. In the Window, right-click and select Create New > Honeycomb > Honeycomb orthotropic 
(28). 
2. For Title, enter Foam. 
3. Enter all the material data, as shown in the following image: 
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4. Right-click on the Yield stress function 11 field and click Select in Model to select a curve 
already present in the model. 
5. In the Function file window, select the function with ID of 5, then select OK. 
6. Repeat this process for the Yield functions, as shown in the following image. 
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7. Click the Tree tab and select the part HCFoam (7) on the tree. 
8. Click to show only this part. 
9. Click the Material tab. 
10. Right-click in the entry box Support, and click Include picked parts to select the part 
HCFoam in the graphics area as shown in the following image. 
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11. Click Yes in the lower right corner. 
12. Click Save > Close. 
Step 5: Create and assign a property 
1. Click Model > Property. 
2. In the Window, right-click and select Create New > Surface > Shell (1), as shown below. 
 
3. For Title, enter Shell Property. 
4. Enter Shell thickness and Shell element formulation values, as shown in the following 
image. 
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5. Click the Tree tab and select the parts Inner, Outer and Flat on the tree. 
6. Click to show only these parts. 
7. Click the Property tab. 
8. Right-click in the entry box Support, and click Include picked parts to select the parts 
Inner, Outer and Flat in the graphics area to assign Shell property. 
9. Click Yes in the lower right corner. 
10. Click Save. 
Step 6: Create and assign a property for Impactor and Support 
1. For Title, enter Rigid Property. 
2. Enter the Shell thickness value as .9119, as shown in the following image. 
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3. Click the Tree tab and select the parts Impactor and Support in the tree. 
4. Click to show only these parts. 
5. Click the Property tab. 
6. Right-click in the entry box Support and click Include picked parts to select the parts 
Impactor and Support in the graphics area to assign the Rigid property. 
7. Click Yes in the lower right corner. 
8. Click Save. 
Step 7: Create and assign a property for HCFoam 
1. In the Window, right-click and select Create New > Volume > General solid (14). 
2. For Title, enter Foam. 
3. Click the Tree tab and select the part HCfoam on the tree. 
4. Click to show only this part. 
5. Go back to the Property tab. 
6. In the Flag for solid elements formulation, select HEPH. 
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7. Right-click in the entry box Support and click Include picked parts to select HCfoam in 
the graphics area to assign Foam property. 
8. Click Yes in the lower right corner. 
9. Click Save > Close. 
Step 8: Create rigid body for Impactor 
1. From the menu bar, click Mesh Editing > Rigid Body. 
2. In the window, right-click to select Create New, enter the name Impactor. 
3. Click the Tree tab and select the Impactor assembly on the tree. 
4. Click to show all parts. 
5. Click the Mesh Editing tab. 
6. Right-click in the entry box Support and right-click in the graphic area (as shown below). Select 
Include picked parts option to select Impactor in graphic area. 
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7. Click Yes > Save. 
Step 9: Create rigid body for Support 
1. In the Title field, enter the name Support. 
2. Click in the entry box Support and right-click in the graphic area. Click Include picked parts 
 option to select Support in the graphic area. 
3. Click Yes to complete the selection. 
4. Click Save. The rigid body for Support should look like the following image. 
 
5. Click Close. 
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Step 10: Define boundary conditions for the model 
1. Click LoadCase > Boundary Condition. 
2. In the window, right-click to select Create New. 
3. Press F6 to show the rigid bodies. 
4. In the Title field, enter Boundary. 
5. Right-click in the entry box Support and right-click in the graphic area. Click Add/Remove 
nodes by picking selection and select the master node of the rigid body. 
 
6. Constrain all DOF except translation in Z as shown in the following image. To constrain the 
nodes, check the boxes for TX, TY, RX, RY and RZ. 
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7. Click Save. 
8. Repeat the same process to create boundary conditions for the Support and Symmetry boundary 
condition for the inner/outer/flat. 
9. Click node selection icon to select master node of Support, as shown in the following 
image. 
 
10. Constrain all DOF by selecting TX, TY, TZ, RX, RY and RZ, as shown in the following image. 
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11. Click Save. 
12. In the Boundary condition creation field, enter Symmetry. 
13. Click the Tree tab and select the parts Inner, Outer, HCfoam and Flat on the tree. 
14. Click to show only these parts. 
15. Press the p key to change the perspective visualization. 
16. Click the Boundary Condition tab. 
17. From the Visualization toolbar, select the YZ View, as shown below. 
 
18. Right-click in the entry box Support, right-click in the graphic window, and click Add nodes by 
box selection to select the nodes, as shown in the image below 
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19. To constrain the nodes, select TY, RX and RZ. 
 
20. Click Save > Close. 
Step 11: Define Impactor Velocity 
1. Click LoadCase > Imposed > Imposed Velocity. 
2. In the window, right-click to select Create New. 
3. For Title, enter IMPOSED VELOCITY. 
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4. For Direction, select Z (translation) and -1000 for Y-Scale factor. 
5. For Time function, use the predefined curve in the model Funct 1. 
6. For Y Scale factor, enter -1000. 
7. Press the F6 key to show the rigid bodies. 
8. Click in the entry box Support and right-click in the graphic area. Click and select the master 
node of Impactor. 
9. Click Yes in the lower-right corner. 
 
10. Click Save > Close. 
Step 12: Define contacts for the model 
1. Click LoadCase > Contact Interface. 
2. In the window, right-click and select Create New > Multi usage (Type 7). 
3. Click on the check box next to Create symmetric interface at saving. 
4. For Title, enter Support. 
5. Click the Tree tab and select the parts Flat and Support on the tree. 
6. Click to show only these parts. 
7. Click the Contact Interface tab. 
8. Set Min gap for impact active to 0.2. 
9. Set Coulomb friction to 0.1. 
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10. Set [Iform] Friction penalty formulation at 2 [Stiffness]. 
11. Click in the Slave nodes entry box and right-click in the graphic window. A menu appears, click 
Include Picked Parts and select the FLAT. 
12. Press Y or click Yes at the bottom right of the screen. HyperCrash will automatically move to 
the selection of the Master surface. 
13. Right-click and click Include Picked Parts and select the Support. 
14. Press Y or click Yes at the bottom right of the screen. 
 
15. Click Save. 
16. Repeat the same process to create contact between Outer and Impactor. 
17. Click the Tree tab and select the parts Outer and Impactor on the tree. 
18. Click to show only these parts. 
19. Right-click in the window and select Create New > Multi usage (Type 7). 
20. Click the Contact Interface tab. 
21. Click on the check box next to Create symmetric interface at saving. 
22. In the Title, enter Imp_Outer. 
23. Set Min gap for impact active to 0.2. 
24. Set Coulomb friction to 0.1. 
25. Set [Iform] Friction penalty formulation to 2 [Stiffness]. 
26. Select Outer Part as Slave and Impactor as Master, as shown in the following image. 
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27. Click Save. 
28. Repeat the same process for self impact for Outer, Inner and Flat, as self impact. 
29. Click the Tree tab and select the parts Outer, Inner and Flat on the tree. 
30. Click to show only these parts. 
31. Click the Contact Interface tab. 
32. Select Self-Impact. 
33. Set Title as Self. 
34. Set the Min gap for impact active to 0.7. 
35. Set the Coulomb friction to 0.1. 
36. Set [Iform] Friction penalty formulation to 2 [Stiffness]. 
37. Select components Outer, Inner and Flat, as shown in the following image. 
 
38. Click Save. 
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Step 13: Clean the model 
1. Click Mesh Editing > Clean. 
 
2. Select All. 
3. Click Clean > Close. 
Step 14: Export the model 
1. Click Model > Control Card and select the control cards in the images below. 
Note: Make sure to save each control card before editing the next. 
 
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2. Click File > Export > RADIOSS. 
3. In the Output window that opens, enter the name 3PBENDING and click OK. 
4. Leave the Header of RADIOSS File window empty and click Save Model. 
The Starter file 3PBENDING_0000.rad is written. 
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Step 15: Open RADIOSS Manager from windows Start menu 
 
Step 16: Run the model 3PBENDING_0000.rad using RADIOSS Manager in 
the class_exercise folder 
Step 17: Review the listing files for this run and verify on the results 
1. Using HyperView, plot the displacement and strain contour. 
 
Plastic Strain Simple Average and Rigid Body Force (Impactor) 
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RD-3150: Seat Model with Dummy using HyperCrash 
Introduction 
 
 
This tutorial presents the different steps involved in building a simple Sled model using HyperCrash 
pre-processing tool. 
Exercise 
 
 
Step 1: Model Import 
Set the User Profile, units and interface. 
1. Open HyperCrash 2017. 
2. For User Profile, select RADIOSS V14. 
3. For Unit System, select N_mm_s_T. 
4. For User Interface Style, select New. 
5. Click Run. 
Step 2: Import the seat model and merge all components, floor, seatbelt 
and foam block 
1. Click File > Import > RADIOSS. 
 
2. Select the file SEAT__00D00.rad. 
3. Click OK. 
Step 3: Model Merging 
1. Click File > Import > RADIOSS. HyperCrash message window prompt. 
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2. Click Merge. 
3. Select the file FLOORD00.rad. 
4. Click OK. 
5. In the Set all to field, enter the value 100000. 
6. Click the Set all to button to offset the numbering of all the entities. 
 
7. Click Merge to merge the floor model. 
8. Redo the steps 1 to 7 for the cushion model: 
 File: FOAMD00.rad 
 Set all to offset: 200000 
9. Redo the steps 1 to 7 for the seatbelt model: 
 File: BELTD00.rad 
 Set all to offset: 300000 
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Step 4: Model Hierarchy 
1. In the Tree, select the subset of the seat named Seat model (300005). 
2. Right-click and select Change Name. 
 
3. In the Change Name window, enter the name Seatbelt. 
4. Click Ok. 
5. Click any item on the tree, right-click and select New Assembly. 
6. Enter the name Frame and click Ok. 
7. Select the parts Seat plate, Backseat plate, Feet, Seat frame, and Backseat frame using 
the SHIFT or CTRL keys. 
8. Press and hold the middle mouse button and drag the selected parts into the new assembly 
Frame. 
9. Select the Tree root (Seat) and right-click. 
10. In the pop-up menu, select List Selection. The List Selection dialog opens. 
 
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11. In the displayed window, check if all parts have properties (PID) and materials (MID). 
12. Click Close and Export the model to save. 
Step 5: Connection 
To add the feet of the seat and the seatbelt anchorage point to the floor rigid body. 
 
1. Click Mesh Editing > Rigid Body. 
2. Select the rigid body: Floor. 
3. Click See selected rigid bodies ( ). 
4. Click Display All and then Left View (F11). 
5. Right-click in the Grnod_Id entry box and click Select in graphic, click Add nodes by box 
selection and select all the nodes of the seat, feet and the anchorage points of the seatbelt. 
6. Right-click to validate. 
7. Select the Floor rigid body in the list, right-click and add the rigid body and master node to time 
history. 
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Connect Seat Cushion to the seat frame with a tied interface (Type 2) 
 
 
1. Click LoadCase > Contact Interface. 
2. Right-click in the window and select Create New > Kinematic condition (Type 2). 
 
3. Display only the cushion parts. Press F11 for XZ view, select Slave nodes section, and click 
Add noes by box selection. 
4. Holding down the SHIFT key, click to draw a polygon windowaround nodes on the backside of 
cushion of the nodes. 
Tip: Press the letter P for non-perspective view, if needed. 
 
Press SHIFT and draw a closed polygon window around the 
nodes to select. When finished, release the SHIFT key. 
5. Display Frame Assembly in the Tree, pick Master surface section, click Add/Remove a 
face and pick one element on each part of the frame facing the cushion. Then select the 
Expand option on the lower right corner to pick select all. 
6. Select the Expand option on the lower right corner to select all the elements of the seat 
assembly facing the seat cushions. 
7. Click Yes or Enter on the keyboard to end the selection. 
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Slave Master 
8. For the Title of the contact, enter seat cushion fixation. 
9. Click Save. 
10. Click at the top of the interface panel, to check the interface. The created interface should be 
displayed with green text, as shown below. Otherwise, the interface has to be modified. 
 
11. Click Close. 
12. Export the model to save. 
Step 6: Dummy positioning 
1. Click Safety > Dummy Positioner. 
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2. From the Dummy model list menu, select New dummy. 
 
A DummyMng panel opens. 
3. Select the File subpanel. 
4. Select the file H350R12BD00. The dummy model is displayed in the small graphic window. 
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5. Click Validate. 
6. Set Set all to value to 400000. 
7. Click the Set all to button to offset the numbering of all entities. 
8. Click OK to merge the Dummy model. 
9. Click Import in the dummy positioning window and select the file H350R12B_Position.M00 
and click OK. 
Note: H350R12B_Position.M00 contains all parameters for the 
automatic dummy positioning. 
 
10. Close the Dummy positioner and Export the model to save. 
 
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Step 7: Seatbelt setting 
1. Click Safety > Belt Generator. 
2. Enter the name Upper belt and click OK to validate. 
 
3. Click Seat belt reference points ( ). 
4. Click Add nodes by picking ( ) and select three nodes, as shown in the following image (red 
dots). 
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5. Click Yes on the right corner and OK to validate the node selection. 
6. Click Add/Remove body parts ( ) and select the parts: torso, pelvis, upper legs, and the 
seat cushion fabric, as shown in red in the image. 
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7. Click Yes to validate the selection. 
8. Set the Gap value to 5.00 mm. 
9. Set the Belt geometric width to 40. 
10. Set the Element Size to 8. 
11. Click Material ( ) and select the material file BELT.mat you saved to your working directory 
from the radioss.zip file. Refer to Accessing the Model Files. 
12. Click OK. 
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13. Click Property ( ) and select the property file BELT.prop you saved to your working 
directory from the radioss.zip file. 
14. Click OK. 
15. Click the Preview button to display the proposed seat belt. Some intersections may exist 
between the seat cushion and the seat belt. 
16. Use the orientation tools to modify the angle of the Rigid Body 2. 
 
 
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17. Click Save to save the belt definition. 
18. Redo the same operations in order to create the lower belt. Select nodes, as shown below: 
 
19. Select the parts: pelvis, upper legs and seat cushion fabric. 
20. Click Preview > Save > Close. 
 
21. Export the model to save. 
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Seatbelt vs Dummy 
 
 
Step 8: Contact interfaces 
During the seatbelt creation, two contact interfaces between the seatbelt and the dummy have been 
created. You will need to check and remove any remaining intersections and penetrations. 
1. Click LoadCase > Contact Interface. 
2. Select interface BELT ID 400038. 
3. Click See selected ( ) to display. 
4. Click in Master Surface, right-click in the graphic area, and click Include picked parts, to 
select the Fabric backframe and the Backseat frame as they may come into contact with the 
shoulder belt during the analysis. 
 
5. Click Save. 
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6. Select interfaces BELT ID 400038 and BELT ID 400039. 
7. Click See selected ( ) to display. 
8. Set Coulomb friction to 0.3. 
9. Set Friction penalty formulation to 2. 
10. Click Save. 
11. Select interfaces BELT ID 400038 and BELT ID 400039. 
12. Click Check penetration selected interfaces ( ). 
13. In the Quality panel remove the intersections and penetrations, using the Depenetrate Auto 
( ). 
14. Click Close in order to come back to the Contact Interface panel. 
15. Export the model to save. 
Seat structure 
Creation of Self-Impact between different parts of the Seat. 
1. In the Tree window, select subsets Frame, Floor and Foam. Click the Isolate icon . 
 
2. Right-click in the Contact list and select Create New > Multi-usage (Type 7). 
3. Click Self impact. 
4. Set the Title to Self impact seat structure. 
5. Set Gap/element option to Variable gap. 
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6. Set Coulomb friction to 0.2. 
7. Set Friction penalty formulation to 2. 
8. Right-click in the Master Surface entry box and click Select in graphics > Add selected 
parts of tree ( ). 
9. Click Save. 
10. Select the self impact seat structure interface in the list. 
11. Click Check penetration selected interfaces ( ). Some penetrations exist between the seat 
cushion and the seat structure. 
12. Switch to the Tree window, and select the subset named Frame. 
13. Switch to the Quality window and click Fixed part ( ). 
14. Press the ESC key to remove all selected parts. 
15. Click Add selected parts of tree ( ). 
16. Click Depenetrate Auto ( ). 
Note: Only the nodes of the seat cushion are moved. The seat parts 
are fixed. 
17. Click Close twice. 
18. Export the model to save. 
Dummy vs Seat 
 
 
Creation of Interface between Dummy and Seat. 
1. Click LoadCase > Contact Interface. 
2. Select interface Create/Modify > Multi usage (Type 7). 
3. In the Tree window, select the Foams subset - the two cushion parts only. 
4. Switch back to the Interface panel and right-click in the Slave Nodes entry box and click 
Select in graphics > Add selected parts of Tree ( ). 
5. Again switch to the Tree window. 
6. Select the subset named HYBRID III 50% DUMMY FINE MESH V_1.2. 
7. Switch back to the Contact interface panel and right-click in the Master Nodes entry box and 
click Select in graphics > Add selected parts of Tree ( ). 
8. Set the interface Title to Dummy - Seat. 
9. Set Coulomb friction to 0.3. 
10. Set GAP MIN to 3.00mm. 
11. Set Friction penalty formulation to 2. 
12. Click Save. 
13. Export the model to save. 
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Dummy vs Floor 
 
 
Creation of an interface between dummy feet and the floor. 
1. Right-click in the Contact list and select Create New > Tied with void (Type 10). 
2. Set the dummy feet as slave nodes. 
3. Set the flooras master surface. 
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4. Set the interface Title to Feet – Floor. 
5. Set Gap for impact activation to 3.0 mm. 
6. Click Save > Close. 
7. Export the model to save. 
Seat Deformer 
 
 
Modifying the seat cushion mesh to conform to the dummy using the Seat Deformer tool. 
Step 1: Edit Pre-simulation settings 
To remove the intersection between the dummy and the set HyperCrash will generate a RADIOSS 
input deck and run a pre-simulation step. The settings for the pre-simulation are defined in the 
menu Option > Presimulation Parameters (for Seat Deformer). For this exercise, modify the 
settings, as shown below: 
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Step 2: Select Seat Parts 
1. In the Tree browser, select Foams assembly, Seat plate, Backseat plate, Seat frame, and 
Backseat frame, as shown below. 
 
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2. Click Safety > Seat Deformer > Pre-simulation (new) and click Add selected parts of 
Tree ( ). 
 
Step 3: Select Fixed Nodes 
1. In the Tree browser, select the Seat plate, Backseat plate, Seat frame and Backseat frame, as 
shown below. 
 
2. Switch back to the Seat Deformer Wizard and click Add selected parts of Tree ( ). 
3. Click Next. 
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Step 4: Select Dummy Parts 
1. Select the dummy parts, as shown below. 
 
2. Click Run and the pre-simulation will start. 
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Step 5: Review the results and apply the deformed shaped 
1. Once the pre-simulation is completed review the results in HyperView by opening the h3d file. 
Create a cut section in the middle of the dummy and verify that the dummy does not 
intersect/penetrate the seat foam. 
 
2. If an intersection/penetration does not exist, go back to the HyperCrash window and load the 
results by clicking Yes in the dialog. 
3. When the job is completed, click Yes to load the results. 
You can also load the results by clicking File > Import > .h3d node coordinates, then click 
Yes to the "Warning: all the nodes coordinates will be replaced by the ones found in the 
selected .h3d file." 
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3. Below is the deformed shape for the seat foam after the pre-simulation. 
 
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After the seat deformation, check if any initial penetrations remain between the seat and 
the dummy. 
1. Click LoadCase > Contact Interface to open the Contact Interface tab. 
2. Select interface Dummy – Seat. 
3. Click Check penetration selected interfaces ( ). Penetrations exist between the seat 
beam and the dummy. 
4. Click Select All ( ). 
5. Click Highlight by Vector ( ). 
 
6. Click Fixed part ( ) . 
7. Press the ESC key to remove all selected parts. 
8. Click Fixed part ( ) and then select the displayed parts of the dummy. 
9. Click Depenetrate Auto ( ). Only the nodes of the seat cushion are moved. The parts of the 
dummy are fixed. 
10. Click Close and then Export the model to save. 
Loadcase Setting 
 
 
Step 9.1: Initial velocity 
Update the initial velocity defined in the model to include all the nodes in the model. 
1. Click LoadCase > Initial Velocity to open the Initial Velocity tab. 
2. Select the initial velocity All in the list. 
3. Click See selected initial velocity ( ). 
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4. Right-click in the Support entry box and click Select in graphics > Add all nodes ( ). 
5. Change [Vx] X Velocity from –10000 to –13000 mm/s. 
 
6. Click Save > Close. 
7. Export the model to save. 
Step 9.2: Imposed velocity 
Update the imposed velocity on the floor to decelerate the car. 
1. Click LoadCase > Imposed > Imposed Velocity. 
2. Select Imposed velocity in the list. 
3. Click See selected imposed velocity ( ). The floor rigid body is displayed on the screen. The 
imposed velocity is defined on its master node. 
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4. Right-click the Time Function entry box and select Edit function. Check if the initial value of 
the function is the same as the initial velocity. 
 
5. Click Save > Close. 
6. Export the model to save. 
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Step 9.3: Boundary conditions 
To simulate the Sled Test, you need to constrain all degrees of freedom on the floor except X-
direction. 
1. Click LoadCase > Boundary Condition. 
2. Select Floor in the list. 
3. Click See selected boundary condition ( ). The floor rigid body is displayed on the screen. 
The boundary condition is defined on its master node. 
4. Verify that the degree of freedom for Ty, Tz, Rx, Ry, and Rz are fixed. 
 
5. Click Save > Close. 
6. Export the model to save. 
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Time History Data Setting 
 
 
Step 10.1: Nodes 
1. Click Data History > Time History. 
2. Select the node group H350MEF2D00_th_nodes. 
3. Click See selected th ( ). These are the nodes of the dummy rigid bodies. 
4. For the first 5 nodes of the group: 
 Select the node in the list. 
 Click See selected node ( ). 
 Enter a name in the field Node name, as shown in the table. 
 Click Ok. 
 
5. When all labels are defined, click Save > Close. 
6. Export the model to save. 
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Step 10.2: Parts 
1. Click Data History > Time History. 
2. Select the second and third part group on the list. 
 
3. Click Delete selected th ( ). 
4. Click Yes to the question in the main window (Yes or Cancel). The selected parts groups are 
deleted from the model. 
5. Select the remaining part group in the list. 
6. Click See selected th ( ). 
7. Go to the Tree panel and select the root of the tree. 
 
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8. Switch back to the Data History panel and click Add parts by tree selection ( ). 
 
9. Click Save and then Export the model to save. 
Step 10.3: Interfaces 
To add all interfaces to Time History. 
1. Click LoadCase > Contact Interface to open the Contact Interface tab. 
2. Select all interfaces in the list. 
3. Right-click and select Data History > Yes. 
 
Step 10.4: Final Check 
1. Go to Quality Module. 
2. Select Check All Solver Contact Interfaces. 
3. Make sure there are no intersections and initial penetrations; if so, fix them. 
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4. Click Close. 
5. Go to Mesh Editing and clean so all the unused materials and properties are removed. 
Step 11: Create Control Cards and Export the Model 
1. Click Model > Control Cards to create the Control Cards in the images below. 
Note that the /DT/SHELL/DEL command is used to delete some of the rigid body shells to allow 
the dummy’s joints to bend during the simulation. 
 
 
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2. Click File > Export > RADIOSS. 
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3. Enter a name for the model in the file output window and click OK. 
 
4. Write relevant information regarding your model in the Header window. 
5. ClickSave Model. 
The model is now ready to be computed. 
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RD-3160: Setting up Multi-Domain Analysis using HyperCrash 
The objective of this tutorial is to show how to use the Multi-Domain technique. For more 
information on this technique, refer to Multi-Domain. 
The model used is a low speed pole impact on a bumper system. Note that the model is finely 
meshed (average mesh size = 2mm) in the region of the pole impact and coarsely meshed (average 
mesh size = 10mm) elsewhere. 
 
In order to run this analysis using Multi-Domain technique, we have to split this model into two 
domains, one containing the finely meshed region and the other containing the rest. A node to node 
link (/LINK/TYPE4) is then specified at the boundary between the two domains. 
These domains will be created using a pre-processor (using HyperCrash in this tutorial) and the 
options specific to Multi-Domain analysis will be added to the input decks through a text-editor. A 
Multi-Domain master input file will also be created using a text editor. 
For a list of Multi-Domain options, refer to Multi-Domain Input. 
For information on how to create links or connections between domains, refer to Multi-Domain in 
the User's Guide. 
For more information on Multi-Domain Master Input, refer to Multi-Domain Master Input File. 
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Exercise 
 
 
Step 1: Import Full Model 
1. Open HyperCrash 2017. 
2. Set User profile: to RADIOSS V14 and Unit system: to kN mm ms kg. 
3. Click Run. 
4. Click File > Import > RADIOSS to import the model monodomain_0000.rad. 
Step 2: Create Input Files for the Two Domains 
1. Click Model > Control Card to set the Control Cards, as shown in the following images: 
 
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2. In the Tree, select the subsets of the fine-meshed region (subsets BB_fine1 (21), BB_fine2 
(24), and fine_mesh (69)), then right-click, then click Export Selection. 
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2. In the Export Selection window, select the option to Add model’s control card not linked to 
any part, toggle Export geometry and select ALL POSSIBLE RELATED ENTITIES. 
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3. Click Ok. 
4. Save the file as fine_mesh. This will write the file fine_mesh_0000.rad. 
5. Click Model > Control Card and enter the following Control Cards: 
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6. In the Tree, select the subsets/spotwelds of the coarse-meshed region, then right-click 
Export Selection. 
7. In the Export Selection window, select the option to Add model’s control card not linked to 
any part, toggle Export geometry and select ALL POSSIBLE RELATED ENTITIES. 
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8. Click Ok. 
9. Save the file as coarse_mesh. This will write the file coarse_mesh_0000.rad. 
Step 3: Define Link between the Two Domains 
1. In the original single model, the fine meshed region is connected to the coarse meshed region at 
both ends. When this model is split into two domains, we have to create a set of nodes in both 
the domains and link these node sets through the starter option (/EXTERN/LINK). This option 
has to be added to the two Starter input files using a text editor. 
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2. Open the Starter file coarse_mesh_0000.rad and add the option /EXTERN/LINK, as shown 
below: 
 
Note: Two external links through node sets 1001 and 1002 have 
been added to this domain. These node sets were already 
defined in monodomain_0000.rad and exported to the two 
domains in Step 2. 
3. Open the Starter file fine_mesh_0000.rad and add the same options. 
4. Create a RAD2RAD input file input.dat defining the two domains and specifying the connections 
between them. 
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5. The input files are now ready to be run using the Multi-Domain technique. For information on 
how to launch a Multi-Domain computation, refer to Multi-Domain. 
 
Exercise Expected Results 
 
 
 
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HyperMesh 
 
RD-3500: Tensile Test Setup using HyperMesh 
This tutorial demonstrates how to simulate a uniaxial tensile test using a quarter size mesh with 
symmetric boundary conditions. 
The model is reduced to one-quarter of the total mesh with symmetric boundary conditions to 
simulate the presence of the rest of the part. 
 
Model Description 
 
 
 UNITS: Length (mm), Time (ms), Mass (kg), Force (kN) and Stress (GPa) 
 Simulation time Rootname_0000.rad [0 – 10.] 
 Boundary Conditions: 
o The 3 upper right nodes (TX, RY, and RZ) 
o The center node on left is totally fixed (TX, TY, Rx, RY, and RZ) 
o A symmetry boundary condition on all bottom nodes (TY, Rx, and RZ) 
 At the left side is applied a constant velocity = 1 mm/ms on -X direction. 
 Tensile test object dimensions = 11 x 100 with a uniform thickness = 1.7 mm 
 
Johnson-Cook elastic plastic material /MAT/PLAS_JOHNS (Aluminum 6063 T7) 
[Rho_I] Initial density = 2.7e-6 Kg/mm3 
[E] Young’s modulus = 60.4 GPa 
[nu] Poisson’s ratio = 0.33 
[a] Yield Stress = 0.09026 GPa 
[b] Hardening Parameter = 0.22313 GPa 
[n] Hardening Exponent = 0.374618 
[SIG_max] Maximum Stress = 0.175 GPa 
[EPS_max] Failure Plastic Strain = 0.75 
Input file for this tutorial: TENSILE_000.rad 
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Exercise 
 
 
Step 1: Load the RADIOSS (Block) User Profile 
1. Launch HyperMesh Desktop. 
2. From the Preferences menu, select the User Profiles or from the toolbar, click the icon. 
3. Select RADIOSS (Block140) and click OK. 
Step 2: Load the solver deck 
1. Click File > Import > Solver Deck or click . 
2. Click the Select File icon to open the TENSILE_0000.rad file you saved to your working 
directory from the radioss.zip file. Refer to Accessing the Model Files. 
3. Click Open. 
4. Click Import. 
5. Click Close to close the window. 
Step 3: Define material for the tensile test object 
1. In the Model browser, right-click and select Create > Material. 
A Material with name material1 of card image M1_Elastic appears in the Entity Editor (EE) in 
the bottom pane of the Model browser. 
2. In the Entity Editor (EE), for Name, enter Mat_1 in the Value field. 
3. Set Card Image to M2_PLAS_JOHNS_ZERIL. 
4. Click Yes on the pop-up that warns of a card image change. 
5. Input the values, as shown in the following image in the EE. 
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Step 4: Define property for the tensile test specimen 
1. In the Model browser, right-click and select Create > Property. 
A Property with name property1 of card image P1_SHELL appears in the Entity Editor (EE) in 
the bottom pane of the Model browser. 
2. For Name, enter sheet_1.7. 
3. For Thick, enter 1.7. in the Value field corresponding to sheet thickness. 
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Step 5: Assign material and property to the test specimen 
1. In the Model browser, select the SHELL_1 component. The Entity Editor opens for the 
component. 
2. For Name, enter Tensile_coupon. 
3. Click Prop_Id, to activate the option. 
4. Click Unspecified >Property. 
5. In the Select Property dialog, select sheet_1.7 from the list and click OK. 
6. Repeat steps 3 - 5 for Mat_Id and select Mat_1. 
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Step 6: Create boundary conditions 
1. From the Utility browser, start the BCs Manager from the pull-down menu, select Tools > BCs 
Manager. 
2. For Name, enter constraint1, set Select type to Boundary Condition and set GRNOD to 
Nodes. 
 
3. Click on Nodes. A nodes selection appears. Select the three nodes, as shown in the figure 
below and click proceed. 
 
4. Fix degrees of freedom Tx, Ry and Rz. 
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5. Click Create to create the constraint. The created constraint appears in the table, and handles 
appear in the graphics area. 
6. For Name, enter constraint2, set Select type to Boundary Condition and set GRNOD to 
Nodes. 
7. Select the node, as shown in the image below. 
 
8. Fix degrees of freedom Tx, Ty, Rx, Ry and Rz. 
 
9. Click Create to create the constraint. The created constraint appears in the table, and a handle 
appears in the graphics area. 
10. For Name, enter constraint3, set Select type to Boundary Condition and set GRNOD to 
Nodes. 
11. Select the nodes, as shown in the image below. 
 
12. Fix degrees of freedom Ty, Rx and Rz. 
13. Click Create to create the constraint. The created constraint appears in the table, also handles 
appear in graphics. 
Step 7: Create Imposed Velocity 
1. For Name, enter velocity, set Select type as Imposed Velocity and set GRNOD to Nodes. 
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2. Select the nodes, as shown in the image below. 
 
3. Set the direction as X and Scale Y as -1.0. 
4. Click Create/Select curve ID for Curve ID. An XY curve editor appears. 
5. Click New to create a new curve. 
6. For Name, enter Load and click proceed. 
7. Enter the values, as shown in table below. 
 
8. Click Update to update the curve with the new values. 
9. Click Close to close the Curve editor, the created curve is assigned to this constraint. 
10. Click Create to create the velocity boundary condition. 
11. Click Close to close the BCs Manager. 
Step 8: Create output requests and control cards 
For this exercise the output request will be generated from the Engine file assistant which is located 
in the Utility browser. 
1. To start the Engine file assistant, select Tools > Engine File Assistant. 
2. Input the values, as shown below: 
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The tool generates typical output requests, such as stress, strain, velocity, etc. 
 
Step 9: Export the model as TENSILE_0000.rad 
1. From the File menu, click Export > Solver Deck or click the Export Solver Deck icon . 
2. For File:, click the folder icon and navigate to the destination directory where you want to 
export to. 
3. Enter the name TENSILE_0000.rad and click Save. 
4. Click the downward-pointing arrows next to Export options to expand the panel. 
5. Select Merge starter and engine file to export the Engine and Starter file as one file. 
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6. Click Export > Close. 
Step 10: Open RADIOSS Manager from Start menu 
Step 11: Run the model TENSILE_0000.rad using RADIOSS Manager 
1. Select the TENSILE_0000.rad for the Input file. 
2. Click Run. 
 
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Step 12: Review the listing files for this run and verify the results 
1. See if there is any warning or errors on .out files. 
2. Using HyperView, plot the displacement and strain contour. 
Exercise Expected Results 
 
 
 
Total Displacement Contour (mm) 
 
Plastic Strain Contour 
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RD-3510: Cantilever Beam with Bolt Pretension 
This tutorial demonstrates how to simulate a simple cantilever problem with a concentrated load at 
the free end, using Dynamic Relaxation (/DYREL) method to obtain a static solution. 
 
Model Description 
 
 
 UNITS: Length (mm), Time (ms), Mass (kg), Force (kN) and Stress (GPa) 
 Simulation time: 
o CANTILEVER_0000.rad [0 – 25.1 ms] 
 Steps to setup this model: 
o Fix the Cantilever Beam to the support with a 10 kN pre-tension. The bolt attains 10 kN in 
10 ms and remains constant thereafter. 
o After pre-tension, a concentrated load of 0.2 kN is gradually applied at the free end of the 
beam from 10 ms to 25 ms and it remains constant thereafter. 
 Material used: 
Elasto-plastic material /MAT/LAW2. 
[Rho_I] Initial density = 7.83e-6 Kg/mm3 
[E] Young’s modulus = 205 GPa 
[nu] Poisson’s ratio = 0.29 
[a] Yield Stress = 0.792 GPa 
[b] Hardening Parameter = 0.510 GPa 
[n] Hardening Exponent = 0.26 
[SIG_max] Maximum Stress = 0.95 GPa 
[c] Strain rate coefficient = 0.014 GPa 
[EPS_0] Reference strain rate = 1 
Input file for this tutorial: CANTILEVER_0000.rad 
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Exercise 
 
 
Step 1: Load the RADIOSS (Block) User Profile 
1. Launch HyperMesh Desktop. 
2. From the Preferences menu, select the User Profiles or from the toolbar, click the icon. 
3. Select RADIOSS (Block140) and click OK. 
Step 2: Load the solver deck 
1. Click File > Import > Solver Deck or click . 
2. Click the Select File icon to open the CANTILEVER_0000.rad file you saved to your working 
directory from the radioss.zip file. Refer to Accessing the Model Files. 
3. Click Open. 
4. Click Import. 
5. Click Close to close the window. 
Step 3: Create a rigid body connecting spring ends to Bolt Support 
component 
1. In the Model browser, right-click and select Create > Component. 
A component is created and is shown in the Entity Editor (EE), below the Model browser. 
2. Using the Entity Editor (EE), change the Name to Rigids. 
3. Set the Card Image as None. 
4. In the Model browser, hide the component 1. 
5. Click the Mask icon in the toolbar. 
6. In the graphics area, select one element from the bolt. 
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7. Click on elems >> by attached to select the whole bolt. 
8. Click mask to hide them and click return. 
9. From the 1D page, select the rigids panel. 
10. Click the selector arrow nodes 2-n: and change it to multiple nodes. 
11. In the rigids panel, for primary node, select the node at the end of spring, as shown in Fig 1 
below, and for nodes 2-n, select the nodes, as shown in Fig 2. 
Note: Be sure to set the selector to multiple nodes. 
 
Fig 1 
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Fig 2 
12. With all the DOF’s checked, click create to create the rigid body. 
13. Click the Mask icon in the toolbar and click reverse to show remaining elements of the bolt. 
14. Click return to exit the panel. 
15. In the Model browser, rght-click the 3 components and click Show to display onscreen, as 
shown below. 
16. Use Steps 3.10 through 3.12 to create a rigid body with the nodes shown in the following image 
with the other ends of the springs as the primary node and the nodes on the bolts as slave 
nodes. 
 
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Step 4: Create and assign material, property to Plate and Support bolts 
1. In the Model browser, click the component 1. The component appears in the Entity Editor. 
2. Change the name of the component to Plate. 
3. Set Card Image to Part. 
4. In the Modelbrowser, right-click and select Create > Material. 
5. For Name, enter Steel and set the Card Image to M2_PLAS_JOHNS_ZERIL and click Yes to 
confirm. 
6. Enter the values, as shown below. 
 
7. In the Model browser, right-click and select Create > Property. 
8. For Name, enter Plate, and set the Card Image to P14_SOLID and click Yes to confirm. 
9. In the Model browser, click the component 2, the EE for the component opens. 
10. For Name, enter Bolt_Support. 
11. Set the Card Image to Part. 
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12. For Prop_Id, click Unspecified > Property and select the property, Plate and click OK. 
13. For Mat_Id, click Unspecified > Material and select the material, Steel and click OK. 
Step 5: Create and update properties for Pre-tensioner Spring 
1. In the Model browser, select the component 3, which opens the Entity Editor. 
2. For Name, enter Spring. 
3. Set the Card Image to Part. 
4. In the Model browser, right-click and select Create > Property. A new property is created and 
a dialog opens with the new property. 
5. Change the Name to Spring. 
6. Set the Card Image to P32_SPR_PRE and click Yes to confirm. 
7. Fill in the other values, as shown below: 
 
8. In the Model browser, click on the property Spring to open the Entity Editor. 
9. Right-click on IFUN2 and select Create to create and attach a curve. A Create Curve dialog 
opens. 
10. Change the Name of the curve to Stiffness. 
11. Click Close to exit the dialog. 
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12. In the Model browser, select the curve Stiffness, right-click and select Edit from context menu. 
13. The XY curve editor appears. Fill in the values, as shown below. 
 
14. Click Update > Close. The created curve is assigned to the property. 
Step 6: Defining Boundary Conditions to fix bottom of the BOLT_SUPPORT 
1. From the Tools menu, start the BCs Manager. 
2. For Name, enter FIXED, set Select type to Boundary Condition and set GRNOD to Nodes. 
 
3. Click on the nodes, the nodes selection appears; by window option, select the bottom layer of 
the bolt support, as shown below and the selection should appear as shown below in the XY 
Plane view: 
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4. Fix all translational degrees of freedom. 
 
5. Click Create to create the constraint. The created constraint appears in the table and a handle 
appears in graphics area. 
Step 7: Defining the load (CLOAD) of the edge of the beam 
1. For Name, enter LOAD, set Select type to Concentrated Load and set GRNOD to Nodes. 
2. Select the nodes on the edge of the beam, as shown in the image below by window option. 
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3. For Direction, select Y. 
4. Set Scale Y, to -1.0 to apply load in negative Y direction. 
5. Click the Create/Select curve tab. A GUI to enter curve appears. 
6. Create a curve with Name LOAD and enter the values, as shown below using the same 
procedure explained in Step 5. 
x = {0, 10, 25, 250} 
y = {0, 0, 0.02, 0.02} 
7. Click Update and Close in the XY curve editor GUI, the created curve is assigned to the BC. 
8. Click Create to finish the creation of the load at the selected nodes. 
Step 8: Define a contact interface between Plate and Support_Bolt 
1. In the Model browser, right-click and select Create > Contact. A contact is created and the 
Entity Edit opens. 
2. Set Name as SELF. 
3. Set Card Image to TYPE7 and click Yes to confirm. 
4. Click on Grnod_id (S) in the EE and set the selector to Components. 
5. Pick the components Plate and Support_Bolt using the list selection dialog. 
6. Click on Surf_id (M) in the EE and set the selector to Components. 
7. Pick the components Plate and Support_Bolt using the list selection dialog. 
8. Set Igap to 0. 
9. For FRIC, enter 0.1 and for GAPmin, enter 0.04. 
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Step 9: Create time history to obtain displacement at free end 
1. In Model browser, right-click and select Create > Output Block from the Analysis page, select 
the output block panel. 
2. In the Entity Editor, set the name to Deflection and select the nodes on the free end of the 
cantilever, as shown in the following image: 
 
3. Set NUM_VARIABLES to 1 and click on the Data:Var icon . A table will open, enter the 
variable name DEF. 
4. Click edit and enter the variable name DEF. 
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Step 10: Create output request and control cards 
For this exercise the output request will be generated from the Engine file assistant which is located 
in the Utility browser. 
1. To start the Engine file assistant, select Tools > Engine File Assistant. 
2. Input the values, as shown below: 
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Step 11: Run the model checker 
1. Click Tools > Model Checker > RadiossBlock to open the Model Checker tab. 
2. The Model Checker will display a list of perceived errors within the model. 
For most of these issues, the Model Checker is equipped to auto-correct many issues, decreasing 
the possibility of a solver error. 
3. Click the Apply Auto Correction icon and click the Run icon to auto-correct issues within 
the model. 
Step 12: Export the model 
1. Click File > Export or click the Export icon . 
2. For File:, click the folder icon and navigate to the destination directory where you want to 
export to. 
3. For Name, enter CANTILEVER and click Save. 
4. Click the downward-pointing arrows next to Export options to expand the panel. 
5. Select Merge starter and engine file to export both the Starter and Engine file in one file. 
6. Click Export to export the file. 
Step 13: Run the model in the solver 
1. Go to Start > Programs > Altair HyperWorks 2017 > RADIOSS. 
2. For Input file, browse to the exercise folder and select the file CANTILEVER_0000.rad. 
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3. Post-process the results with HyperView. 
4. Using HyperGraph, open the T01 file and plot the deflection at the free end of the cantilever. 
 
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RD-3520: Pre-Processing for Pipes Impact using RADIOSS 
For this tutorial it is recommended to complete the introductory tutorial, HM-1000: Getting Started 
with HyperMesh. Working knowledge of the creation and editing of collectors and card images are a 
definite pre-requisite. Familiarity with the Interfaces panel, and the creation of boundary conditions 
are useful, although not required. 
Objective 
 
 
In this tutorial you will learn how to set up a RADIOSS input file in HyperMesh for analyzing the 
impact response between two pipes. The modeling steps that are covered are: 
 Creating materials, sections, and parts for the model. 
 Defining the contact between the two pipes using /INTER/TYPE7. 
 Applying a translational initial velocity to a pipe using the /INIVEL card. 
 Applying local constraints to the other pipe using the /BCS card. 
Model Description 
 
 
The units used in this tutorial are milliseconds, millimeters and kilograms (ms, mm, kg), and the 
tutorial is based on RADIOSS 14.0. 
 
Pipe model 
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Exercise 
 
 
Step 1: Load the RADIOSS (Block) User Profile 
1. Launch HyperMesh Desktop. 
2. From the Preferences menu, select the User Profiles or click the icon on the toolbar. 
3. Select RADIOSS(Block140) and click OK. 
Step 2: Import the solver deck 
1. Click File > Import > Solver Deck or click . 
2. Click the Select File icon to open the pipesd00.rad file you saved to your working directory 
from the radioss.zip file. Refer to Accessing the Model Files. 
3. Click Import. The model loads into the graphics area. 
Note: On import of a RADIOSS deck, any HyperMesh warning and 
error messages are written to a file named radiossblk.msg. 
This file is created in the folder from which HyperMesh is 
started. The content of the file is also displayed in a pop-up 
window. 
On import, any RADIOSS cards not supported by HyperMesh 
are written to the control card unsupp_cards. This card is 
accessed from the control cards panel on the BCs page and is a 
pop-up text editor. The unsupported cards are exported with 
the rest of the model. 
Care should be taken if an unsupported card points to an entity 
in HyperMesh. An example of this is an unsupported material 
referenced by a /PART card. HyperMesh stores unsupported 
cards as text and does not consider pointers. 
On import, HyperMesh renumbers entities having the same ID 
as other entities. In HyperMesh, for example, all elements 
must have a unique ID. The message file radiossblk.msg 
provides a list of renumbered elements and their original and 
new IDs. 
Step 3: Understand the relationships between the /PART, /SHELL, /MAT 
and /PROP cards in HyperMesh 
A /PART shares attributes such as section properties (/PROP) and a material (/MAT). A group of 
shells (/SHELL) sharing common attributes generally share a common part ID (PID). 
 
 
 
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The figure below shows how these keywords are mapped to HyperMesh entities: 
/SHELL elem_ID part_ID Organized into component 
collectors 
 
/PART part_ID prop_ID mat_ID Component collector with a 
component card image 
 
/PROP prop_ID Property collector with a property 
card image 
 
/MAT mat_ID Material collector with a material 
card image 
 
Map to HyperMesh Entities 
 
 
Component, property and material collectors are created and edited from the Collectors panel. 
For the RADIOSS keyword interface, there is only one component card image and it is named Part. 
There are several property card images, such as P1_SHELL, P2_TRUSS, and P14_SOLID. There are 
many material card images, such as M1_ELAST and M48_HONEYCOMB. 
The complete list of card images is available from the Collectors panel, as you assign card images to 
the various types of collectors. 
A HyperMesh card image allows you to view the image of keywords and data lines for defined 
RADIOSS entities as interpreted by the loaded template. The keywords and data lines appear in the 
exported RADIOSS input file as you see them in the card images. Additionally, for some card 
images, you can define and edit various parameters and data items for the corresponding RADIOSS. 
Use the Entity Editor or card (card editor) panel from the permanent menu to review and edit card 
images. Also, for many entities, their card image can be viewed and edited from the panels in which 
they are created. 
Step 4: Create a /MAT card 
In HyperMesh, a /MAT card is associated to a material collector. To relate it to a /PART card, the 
material needs to be assigned to a component. 
You can assign the material to the component collector as you create the component using the 
Create subpanel of the Collectors panel or from component create options in the pull-downs or from 
the Model browser using the Entity Editor (EE). In situations where the material was not assigned to 
the component at the time of creation (and in this case, a dummy material is created with the same 
name as the component collector), update the component collector's definition by assigning the 
material in the Update subpanel of the Collectors panel or from the Assign option in Model browser 
or using the Entity Editor (EE) of the component. 
In this step, create a material with the M1_ELAST card image using the Model browser. This 
material will be assigned to both pipes. 
1. In the Model browser, right-click and select Create > Material. A material is created and 
displayed in the Entity Editor (EE) below the Model browser. 
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2. For Name, enter elast1. 
3. Set Card Image to M1_ELAST. 
4. In the Entity Editor (EE), click to activate the field. 
Rho_Initial (density), enter 7.8E-6 
E (Young's modulus), enter 208 
nu (Poisson's ratio), enter 0.30 
Note: If you have difficulties completing any task with the creation, 
update or editing of materials in this tutorial, refer to the on-
line help for the materials by clicking Help from the menu. 
Hint: Any material that was mistakenly created with wrong values 
can be edited using the card image option. 
 
In this step, the material created will be used for the analysis. The next step is to define the /PROP 
card that will be used to define the properties of the elements in the model. 
Step 5: Create a /PROP card 
In HyperMesh, the /PROP card is assigned to a property. To generate this card, create a property 
collector using either the Property icon in the toolbar or click Properties > Create from the pull-
down or from the Model browser, click Create > Property. 
The model consists of two pipes modeled with shell elements. Create a property with a 
/PROP/SHELL card that will be used for all the elements. 
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1. In the Model browser, right-click and select Create > Property. A property is created and 
displayed in the Entity Editor (EE). 
2. For Name, enter prop_shell. 
3. Set Card Image to P1_SHELL. 
4. Set Ishell to 24. 
5. For shell thickness Thick, enter 2.5. 
 
Step 6: Assign the /PART, /MAT and /PROP cards to the elements 
Assign the /PART card to the component for the coarse pipe and specify the /PROP/SHELL card ID in 
it. 
1. In the Model browser, select the components Pipe1 and Pipe2. A combined Entity Editor (EE) 
appears for both the selected components. 
2. Set Card Image to PART. 
3. For Prop_Id, click Unspecified > Property and select the property, prop shell and click OK. 
4. For Mat_Id, click Unspecified > Material and select the material, elast1 and click OK. 
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Step 7: Create Interface/Contact cards 
RADIOSS contacts can be created from Model browser, with a right-click Create > Contact, they 
can also be created in the Interfaces panel from the Analysis page or from the menu, select BCs > 
Create > Interfaces. 
A RADIOSS contact is a HyperMesh group. When you want to manipulate a /INTER card, such as 
delete it, renumber it, or turn it off, you need to work with HyperMesh group entities. 
In this step, create a contact between the two pipes using /INTER/TYPE7. The pipe with the coarser 
mesh (2) will be the master surface while the one with finer mesh (1) will be the slave surface. 
RADIOSS has multiple ways to define master and slave entity types from which to choose; in this 
example define the master and slave entities as components, by doing this, the master will be 
exported as /SURF/PART and the slave as a /GRNOD/PART. 
1. In the Model browser, right-click and select Create > Contact. A contact is created and the 
Entity Editor (EE) opens. 
2. For Name field, enter contact. 
3. Set Card Image to TYPE7 and click Yes to confirm. 
4. For Surf_id(M) that corresponds to the master selection, click on the drop-down arrow and 
select Components. 
5. Click Components and select component 2 in the selection or on the graphics window and click 
OK. 
6. For Grnod_id(S) that corresponds to the slave selection, click on the drop-down arrow and 
selectComponents. 
7. Click Components and select component 1 in the selection or on the graphics window and click 
OK. 
8. For static coefficient [Fric], enter 0.10. 
In this step, you defined the contact between the two pipes as /INTER/TYPE7. 
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Step 8: Create boundary conditions 
Boundary conditions for RADIOSS can be efficiently created using the BC’s Manager available on the 
Utility browser. The BC’s Manager can be accessed from the Tools menu. RADIOSS boundary 
conditions are mapped to load collector in HyperMesh. 
In this step, you will apply a translational initial velocity along Z direction to the coarse pipe using 
BC’s Manager. 
1. In the BCs Manager, enter Name as tran_vel and set Select type as Initial Velocity under 
the Create header. 
2. Click Parts, select component 2 from the GUI, and click proceed. This creates the entity set of 
type GRNOD, which is referred to in the /INIVEL card. 
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3. In the BC’s Manager, enter the initial velocity components as 0, 0 and -30 for Vx, Vy and Vz 
fields. 
There is an option for creating/referring the initial velocity card to a local coordinate system. 
However, if nothing is specified, the global coordinate system is selected by default. 
4. Click Create. Cross check in the Model browser for your reference that a load collector and an 
entity set are created. 
This completes the creation of an initial velocity for the pipe in the negative global Z direction. 
Step 9: Create a /BCS and constrain the finer mesh pipe 
In this step, you will fully constrain the end nodes of the bottom pipe by using the Boundary 
Conditions Manager. 
1. In the BCs Manager, enter Name as SPC and set Select type as Boundary Condition. 
2. Now specify the node set of type as GRNOD for the BCS card, switch the entity from Parts to 
Nodes and select the end nodes of the bottom pipe, which are to be constrained. 
3. Under the Boundary condition components subheading (as illustrated below) activate all the 
translational and rotational check boxes. Click Create. 
A load collector with a BCS card is created and applied the nodes as selected in the above steps. 
A corresponding node set is created. 
 
Step 10: Create output definitions and control cards 
For this exercise the output request will be generated from the Engine file assistant which is located 
in the Utility browser. 
1. To start the Engine file assistant, select Tools > Engine File Assistant. 
2. Input the values, as shown below: 
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Step 11: Export the model 
1. Click File > Export or click the Export icon . 
2. For File:, click the folder icon and then navigate to the destination directory where you want 
to export to. 
3. For Name, enter pipe and click Save. 
4. Click the downward-pointing arrows next to Export options to expand the panel. 
5. Select Merge starter and engine file to export both the Starter and Engine file in one file. 
6. Click Export to export the solver deck. 
This concludes this tutorial. You may discard this HyperMesh model or save it for your own 
reference. 
In this tutorial some of the concepts that govern the HyperMesh interface to RADIOSS are 
introduced. You also used numerous panels that allowed you to do basic modeling in terms of 
RADIOSS, such as defining contacts or boundary conditions. 
Step 12: Run the model in the solver 
1. Go to Start > Programs > Altair HyperWorks 2017 > RADIOSS. 
2. For Input file, browse to the exercise folder and select the file pipe_0000.rad. 
 
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Exercise Expected Results 
 
 
 
Deformation and energy balance plot 
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RD-3530: Buckling of a Tube using Half Tube Mesh 
This exercise simulates buckling of a tube using half tube mesh with symmetric boundary 
conditions. 
The figure illustrates the structural model used for this tutorial: a half tube with a rectangular 
section (38.1 x 25.4 mm) and length of 203 mm. 
 
Model Description 
 
 
 UNITS: Length (mm), Time (ms), Mass (kg), Force (kN) and Stress (GPa) 
 Simulation time: Engine [0 – 10 ms] 
 The tube thickness is 0.914 mm. 
 An imposed velocity of 13.3 mm/ms (~30 MPH) is applied to the right end of the tube 
 Elasto-plastic material using Johnson-Cook law /MAT/PLAS_JOHNS (STEEL). 
[Rho_Initial] Initial density = 7.85e-6 Kg/mm3 
[E] Young’s modulus = 210 GPa 
[nu] Poisson coefficient = 0.33 
[a] Yield Stress = 0.206 GPa 
[b] Hardening Parameter = 0.450 GPa 
[n] Hardening Exponent = 0.5 
[SIG_max] Maximum Stress = 0.0 GPa 
File needed to complete this tutorial: tube_box.hm 
 
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Exercise 
 
 
Step 1: Load the RADIOSS User Profile 
1. Launch HyperMesh Desktop. 
2. From the Preferences menu, select the User Profiles or click the icon on the toolbar. 
3. Select RADIOSS (Block140) and click OK. 
Step 2: Load the model 
1. From the toolbar, click the Open Model icon to open the tube_box.hm file you saved to your 
working directory from the radioss.zip file. Refer to Accessing the Model Files. 
2. Click Open. The model loads into the graphics area. 
Step 3: Create Material for the tube 
1. In the Model browser, right-click and select Create > Material. The Entity Editor is displayed 
below the Model browser. 
2. For Name, enter Steel. 
3. Set Card Image to M2_PLAS_JOHNS_ZERIL and click Yes to confirm. 
4. Set Type as PLAS_JOHNS. 
5. Input the values, as shown below: 
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6. Click anywhere in the Model browser to exit the Entity Editor. 
Step 4: Create Property for the tube 
1. In the Model browser, right-click and select Create > Property. The Entity Editor is displayed 
below the Model browser. 
2. For Name, enter Pshell. 
3. Set Card Image to P1_SHELL. 
4. Input the values, as shown below: 
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Step 5: Assign material and property to the component 
1. Select the component Tube_box in the Model browser. 
2. In the Entity Editor, for Prop_Id, click Unspecified > Property 
3. In the Select Property dialog, select Pshell and click OK. 
4. In the Entity Editor, for Mat_Id, click Unspecified > Material. 
5. In the Select Material dialog, select Steel and click OK. 
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Step 6: Create Rigid Body 
1. Create a component collector RBODY. Set Card Image to None in the Entity Editor. 
2. In the 1D page, select rigids. 
3. Set nodes 2-n to multiple nodes. 
4. Set primary node tab to calculate node. 
5. Select the nodes of one edge to tie all the degree’s of freedom, as shown in the image below: 
 
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6. Click create. 
Step 7: Create Symmetry Boundary Conditions 
1. Click Tools > BCs Manager to start the BCs Manager. 
2. For Name, enter Symmetry, set Select type as Boundary Condition and set GRNOD to 
Nodes. 
 
3. Click on the nodes, nodes selection appears; by window option, select the top layer of the 
channel as shown below and the selection should appear as below: 
 
 
 
 
 
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4. Fix the degrees of freedom for symmetry condition, as shown below: 
 
5. Click Create to create theconstraint. The created constraint appears in the table, and a handle 
appears in graphics area. 
Step 8: Create Imposed Velocity 
1. For Name, enter Velocity, set Select type as Imposed Velocity and set GRNOD to Nodes. 
 
2. Select the master node of the RBODY on which the boundary condition needs to be applied. 
 
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3. Set the Direction as Z. 
4. Click Create/Select curve to create imposed velocity loading curve. A new GUI opens. 
5. Click New to enter Load as the name of the curve. 
6. Click proceed. 
7. Enter the X values as 0, 1000. 
8. Enter corresponding Y values as 13.3, 13.3. 
 
9. Click the Create tab to create the constraint. The created constraint appears in the table and a 
handle appears in graphics area. 
Step 9: Create boundary condition on the rigid body 
1. Enter Name as RBODY_constraint, set Select type as Boundary Condition and set the 
GRNOD to Nodes. 
2. Select the master node of the RBODY on which the boundary condition need to be applied. 
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3. Set the degrees of freedom to not allow movement in X and Y direction and no rotation about Y-
axis and Z-axis, as shown below. 
 
4. Click the Create tab to create the constraint. The created constraint appears in the table and a 
handle appears in graphics area. 
Step 10: Create a Rigid Wall 
1. In the Model browser, right-click and select Create > Rigid Wall. 
2. Set the Geometry Type as Infinite plane. 
3. Click on the Base node option and select extreme node opposite to rigid body edge. 
 
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4. Set the normal vector using the N1, N2, N3 option, as shown below. Ensure that N3 is not 
active. Click Proceed. 
 
 
Note: Keep N3 inactive. 
5. Set d (distance) value to 20. 
 
6. Go to Analysis > rigid walls panel. 
7. Move to the Geometry page. Click on the Edit tab besides base node and change the Z value 
to 10.0 to be away from the channel along the Z-axis. 
8. Click update. 
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Step 11: Creating a Self Contact to avoid self penetration during impact 
1. In the Model browser, right-click and select Create > Contact. The Entity Editor will open. 
2. Enter the Name as Self_Interface and set the Card Image as TYPE7 and click Yes to 
confirm. 
3. Toggle the option to Components for Grnod_id (S) (slave entity), select Tube_box and click 
OK. 
4. Toggle the option to Components for Surf_id (M) (master entity), select Tube_box and click 
OK. 
5. Set STFAC = 1, FRIC = 0.20 and GAPmin = 0.90. 
 
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6. Click anywhere in the Model browser to exit the Entity Editor. 
7. To review the created interface, go to the Analysis > Interface panel. 
8. Go to the update subpanel, select created interface and click review. It will show master and 
slave surface as blue and red. 
Step 12: Create output requests and control cards 
1. Launch the HyperMesh Solver browser from View > Browsers > HyperMesh > Solver. 
2. Right-click in the Solver browser general area to create the cards, shown below with the given 
values for each parameter: 
Keyword Type Keyword Parameter Parameter 
Value 
CONTROL CARDS TITLE Status [Checked] 
CONTROL CARDS TITLE TITLE Box_Tube 
ENGINE KEYWORDS RUN Status [Checked] 
ENGINE KEYWORDS RUN Tstop 10.01 
ENGINE KEYWORDS PRINT Status [Checked] 
ENGINE KEYWORDS PRINT N_Print -100 
ENGINE KEYWORDS ANIM/ELEM Status [Checked] 
ENGINE KEYWORDS ANIM/ELEM EPSP [Checked] 
ENGINE KEYWORDS ANIM/ELEM ENERGY [Checked] 
ENGINE KEYWORDS ANIM/ELEM VONM [Checked] 
ENGINE KEYWORDS ANIM/ELEM HOURG [Checked] 
ENGINE KEYWORDS ANIM/VECT Status [Checked] 
ENGINE KEYWORDS ANIM/VECT VEL [Checked] 
ENGINE KEYWORDS ANIM/VECT FOPT [Checked] 
ENGINE KEYWORDS ANIM/VECT CONT [Checked] 
ENGINE KEYWORDS ANIM/DT Status [Checked] 
ENGINE KEYWORDS ANIM/DT Tstart 0 
ENGINE KEYWORDS ANIM/DT Tfreq 1 
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Keyword Type Keyword Parameter Parameter 
Value 
ENGINE KEYWORDS ANIM/NODA Status [Checked] 
ENGINE KEYWORDS ANIM/NODA DMAS [Checked] 
Step 13: Export the model 
1. Click File > Export or click the Export icon . 
2. For File:, click the folder icon and navigate to the destination directory where you want to 
export to. 
3. Enter the name boxtube and click Save. 
4. Click the downward-pointing arrows next to Export options to expand the panel. 
5. Select Merge starter and engine file to export the engine file with the model file. 
6. Click Export to export the file. 
Step 14: Run the solver using RADIOSS Manager 
1. Go to Start > Programs > Altair HyperWorks 2017 > RADIOSS. 
2. For Input file, browse to the exercise folder and select the file boxtube_0000.rad. 
 
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Step 15: Results analysis in HyperView 
Exercise Expected Results 
 
 
 
Total Displacement (mm) and Plastic Strain (Mid Layer, Simple Average) 
 
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RD-3540: Front Impact Bumper Model using HyperMesh 
For this tutorial it is recommended to complete the introductory tutorial HM-1000: Getting Started 
with HyperMesh, as well as RD-3520: Pre-Processing for Pipes Impact Using RADIOSS for the basic 
concepts on the HyperMesh RADIOSS interface. 
In this tutorial you will learn how to use HyperMesh to set up a RADIOSS input deck for analysis of 
the impact of a bumper against a barrier behind rigid wall. The modeling steps that are covered are: 
 Associating /PART, with /MAT and /PROP. 
 Converting node-to-node connections (/RBODY) into a mesh-less welding formulation 
(/INTER/TYPE2 with /SPRING) using HyperMesh connectors. 
 Defining the contact for the elements in the bumper with an /INTER/TYPE7 card. 
 Defining the interaction between bumper and barrier with an /INTER/TYPE7 card. 
 Defining the interaction between barrier and rigid wall with the /RWALL/PLANE and 
/BOX/RECTA cards. 
 Specify the output of resultant forces for a plane on the left interior and exterior crash boxes 
with /SECT. 
 Creating a /TH/NODE card to output time history for nodes. 
The units used in the model are millisecond, millimeter and kilogram (ms, mm, kg), and the tutorial 
is based on RADIOSS Block 14.0. 
Exercise 
 
 
The model used consists of a simplified bumper model (see image below): 
 
Bumper model 
Step 1: Load the RADIOSS (Block) User Profile 
1. Launch HyperMesh Desktop. 
2. From the Preferences menu, select the User Profiles or click the icon in toolbar. 
3. Select RADIOSS (Block140) and click OK. 
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Step 2: Load the bumper.hm file 
1. Click the Open Model icon to open the bumper.hm file you saved to your working directory 
from the radioss.zip file. Refer to Accessing the Model Files. 
2. Click Open. 
The model loads into the graphics area. 
Step 3: Define vehicle mass component to partially take into account the 
inertia properties and mass of the missing parts of the vehicle 
1. In the Model browser, right-click and select Create > Component. The Entity Editor (EE) will 
open. 
2. For Name, enter Vehicle mass. 
3. Set Card Image to None and click Yes to confirm. 
4. Click Geometry > Create > Nodes > XYZ to open the Nodes panel. 
5. In the X field, enter 700. 
6. In the Y field, enter 0. 
7. In the Z field, enter 170. 
8. Click create to create the node. 
9. Go to the 1D page,and click rigids. 
10. Click the selector arrow nodes 2-n: and select sets. 
11. For primary node, select the node created in the steps above. 
12. Click sets and select the Constrain Vehicle set. 
13. With all the DOF’s checked, click create to create the rigid body. 
Note: A spider will be drawn connecting the created node to the 
edge nodes of the structure modeled. 
14. Click Card Edit in the toolbar, set the selector to elements and select the rigid body 
created. 
15. Click edit. 
16. Fill the mass and inertia information in the card image, as shown in the table below: 
Mass JXX JXY JXZ JYY JYZ JZZ 
800 1.5E+07 -5.0E+03 -8.0E+06 5.0E+07 -900 6.0E+07 
17. Set ICOG as 4 and set Ispher as 0. 
18. Click return to exit the panel. 
 
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Step 4: Create a GRNOD/BOX/RECTA that contains all nodes except 
barrier nodes 
1. Click View > Browsers > HyperMesh > Solver to activate the Solver browser, if it is not 
active on your screen. 
2. Right-click in the Solver browser and select Create > BOX > BOX/RECTA. The Entity Editor 
opens. 
3. For Name, enter box velocity. 
4. Optionally, select a Color. 
5. Enter Corner1 and Corner2 X, Y, and Z coordinates, as shown below. 
 
Step 5: Create initial velocity on bumper except barrier 
1. Click Tools > BCs Manager. 
2. In the BCs Manager, enter Name as trans_vel. 
3. Select the Select type as Initial Velocity under the Create header. 
4. Set the entity selector to BOX under GRNOD. 
5. Click on it and select box velocity. 
6. Enter -10, 0, 0 for Vx, Vy and Vz fields, respectively. 
 
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7. After the above step, a set named InitialVelocity_grnodbox is created automatically or you 
can create this set before the above step and then refer to this set in the above step, instead of 
BOX. 
8. Click the Create > Close. 
Step 6: Define master surface for contact 
1. Right-click in the Solver browser and select Create > SURF_EXT > PART. The Entity Editor 
opens. 
2. For Name, enter barrier_surface. 
3. For Entity IDs, click on Components. 
4. In the Select Components dialog, select barrier and click OK. 
 
5. Right-click in the Solver browser and select Create > SURF > PART. The Entity Editor opens. 
6. For Name, enter bumper_surface. 
7. For Entity IDs, click on Components. 
8. In the Select Components dialog, select bumper, exterior crashbox left, exterior crashbox 
right, interior crashbox left, and interior crashbox right and click OK. 
 
9. Right-click in the Solver browser and select Create > SURF > SURF. The Entity Editor opens. 
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10. For Name, enter barrier_bumper_surface. 
11. For Entity IDs, select Sets. 
12. Click on Sets and select barrier_surface and bumper_surface and click OK. 
 
Step 7: Create self impact contact between parts of the bumper 
1. Right-click in the Solver browser and select Create > INTER > TYPE7. The Entity Editor opens. 
2. For Name, enter impact. 
3. For Grnod_id (S) (slave entity), set the selector to Components. 
4. Click Components, select bumper, interior crashbox (left and right) and exterior 
crashbox (left and right) and click OK. 
5. For Surf_id (M) (master entity), set the selector to Set. 
6. Click Set, select barrier_bumper_surface and click OK. 
7. Set Igap to 2. 
8. For the static coefficient Fric, enter 0.15. 
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Step 8: Create a system that specifies the location and the cross section 
plane normal 
1. Click the numbering icon on the toolbar. 
2. Click the nodes selector and select by id. 
3. For the IDs enter 6224, 6227, and 5993. 
4. Check the display check box on. 
5. Click on. 
Note: Node numbers will appear next to the node for selection in 
further steps. 
6. From the Analysis page, click systems. 
7. Go to the create by node reference page. 
8. Select Node ID 6224 for origin node. 
9. Select Node ID 6227 for z- axis. 
10. Select Node ID 5993 for yz plane. 
11. Click create to create a system. 
12. Click the Card Edit icon on the toolbar. 
13. Set the entity selector to systs. 
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14. Select the system and click edit. 
15. Change the option from Skew to Frame. 
16. Click return. 
Step 9: Create a set of elements that will contribute to the cross-sectional 
force results 
1. Right-click in the Solver browser and select Create > GRSHEL > SHEL. The Entity Editor 
opens. 
2. For Name, enter CrosssectionPlane-elements. 
3. For Entity IDs, toggle to Elements selector active, select two rows of element on either side of 
the system, as shown in figure below. 
 
Step 10: Define a section 
1. Right-click in the Solver browser and select Create > SECT > SECT. 
2. For Name, enter Crosssection_Plane. 
3. For Frame_ID, select the system defined in the previous step by clicking on the screen. 
4. For grshel_ID, select the set CrosssectionPlane-elements which is defined in previous step, 
as shown below. 
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Step 11: Select the section for time history output 
1. Right-click in the Solver browser and select Create > TH > SECTIO. 
2. For Name, enter Section_force. 
3. For Entity IDs, toggle Crosssections and select Crosssection_Plane. 
4. For NUM_VARIABLES, select 1 and for Data: Var, enter DEF. 
This selects the default output for RADIOSS. 
 
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Step 12: Create a BOX/RECTA and GRNOD/BOX containing the nodes 
making up the barrier and bumper’s left side 
These nodes will be slave to the rigid wall. 
1. Right-click in the Solver browser and select Create > BOX > BOXRECTA. 
2. For Name, enter half model. 
3. Optionally, select a Color. 
4. Enter Corner1 and Corner2 X, Y and Z coordinates, as shown below: 
 
5. Right-click in the Solver browser and select Create > GRNOD > BOX. 
6. For Name, enter RigidwallSlave_grnodbox. 
7. For Entity IDs, set the selector to Box and select the above created half model (BOX/RECTA). 
 
Step 13: Define a rigid wall 
1. Press the F8 key to enter the create nodes panel. 
2. Select the XYZ ( ) subpanel. 
3. For x=, y= and z=, enter the values –600, -750 and 90, respectively. 
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4. Click create. 
5. Right-click in the Solver browser and select Create > RWALL > PLANE. 
6. For Name, enter wall. 
7. Set Geometry type as Infinite Plane. 
8. With the Base node selector active, select the node that was created in step 4. 
9. Set Normal to 1,0,0. 
10. For grnod_id1 (S), toggle Set and select RigidWallSlave_grnodbox (GRNOD/BOX). 
11. For fric, specify 1.0 for the friction coefficient. 
 
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Step 14: Create output requests and control cards 
1. Launch the HyperMesh Solver browser from View > Browsers > HyperMesh > Solver. 
2. Right-click in the Solver browser general area to create the cards, shown below with the given 
values for each parameter: 
Keyword Type Keyword Parameter Parameter 
Value 
CONTROL CARDS TITLE Status [Checked] 
CONTROL CARDS TITLE TITLE Bumper_Impact 
ENGINE KEYWORDS RUN Status [Checked] 
ENGINE KEYWORDS RUN Tstop 20 
ENGINE KEYWORDS PARITH Status [Checked] 
ENGINE KEYWORDS PARITH Keyword2 ON 
ENGINE KEYWORDS PRINT Status [Checked] 
ENGINE KEYWORDS PRINT N_Print -1000 
ENGINE KEYWORDS TFILE Status [Checked] 
ENGINE KEYWORDS TFILE Time 
Frequency0.1 
ENGINE KEYWORDS ANIM/ELEM Status [Checked] 
ENGINE KEYWORDS ANIM/ELEM EPSP [Checked] 
ENGINE KEYWORDS ANIM/ELEM VONM [Checked] 
ENGINE KEYWORDS ANIM/BRICK/TENS Status [Checked] 
ENGINE KEYWORDS ANIM/BRICK/TENS STRESS [Checked] 
ENGINE KEYWORDS ANIM/BRICK/TENS STRAIN [Checked] 
ENGINE KEYWORDS ANIM/SHELL/TENS/STRESS Status [Checked] 
ENGINE KEYWORDS ANIM/SHELL/TENS/STRESS MEMB [Checked] 
ENGINE KEYWORDS ANIM/SHELL/TENS/STRAIN Status [Checked] 
ENGINE KEYWORDS ANIM/SHELL/TENS/STRAIN MEMB [Checked] 
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Keyword Type Keyword Parameter Parameter 
Value 
ENGINE KEYWORDS ANIM/VECT Status [Checked] 
ENGINE KEYWORDS ANIM/VECT DISP [Checked] 
ENGINE KEYWORDS ANIM/VECT VEL [Checked] 
ENGINE KEYWORDS ANIM/DT Status [Checked] 
ENGINE KEYWORDS ANIM/DT Tstart 0 
ENGINE KEYWORDS ANIM/DT Tfreq 1 
ENGINE KEYWORDS DT/NODA Status [Checked] 
ENGINE KEYWORDS DT/NODA CST 0 – Tmin 3.6e-4 
Step 15: Export the model 
1. Click File > Export or click the Export icon . 
2. For File:, click the folder icon and navigate to the destination directory where you want to 
export to. 
3. Enter the name bumper_impact and click Save. 
4. Click the downward-pointing arrows next to Export options to expand the panel. 
5. Toggle Merge starter and engine file to export the engine file with the model file (or export 
separately). 
6. Click Export to export both model and engine file. 
Step 16: Run the solver using RADIOSS Manager 
1. Go to Start > Programs > Altair HyperWorks 2017 > RADIOSS. 
2. For Input file, browse to the exercise folder and select the file bumper_impact_0000.rad. 
 
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Step 17 (Optional): View the results in HyperView 
The exercise is complete. Save your work to a HyperMesh file. 
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RD-3550: Simplified Car Front Pole Impact 
This tutorial demonstrates how to simulate frontal pole test with a simplified full car. 
 
Model Description 
 
 
 UNITS: Length (mm), Time (s), Mass (ton), Force (N) and Stress (MPa) 
 Simulation time: Engine file (_0001.rad) [0 – 0.0601 ms] 
 An initial velocity of 15600 mm/s is applied on the car model to impact a rigid pole of radius 
250 mm. 
 Elasto-plastic Material /MAT/LAW2 (Windshield) 
[Rho_I] Initial Density = 2.5x10-9 ton/mm3 
[E] Young's Modulus = 76000 MPa 
[nu] Poisson’s Ratio = 0.3 
[a] Yield Stress = 192 MPa 
[b] Hardening Parameter = 200 MPa 
[n] Hardening Exponent = 0.32 
 Elasto-plastic Material /MAT/LAW2 (Rubber) 
[Rho_I] Initial Density = 2x10-9 ton/mm3 
[E] Young's Modulus = 200 MPa 
[nu] Poisson’s Ratio = 0.49 
[a] Yield Stress = 1e30 MPa 
[n] Hardening Exponent = 1 
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 Elasto-plastic Material /MAT/LAW2 (Steel) 
[Rho_I] Initial Density = 7.9x10-9 ton/mm3 
[E] Young's Modulus = 210000 MPa 
[nu] Poisson’s Ratio = 0.3 
[a] Yield Stress = 200 MPa 
[b] Hardening Parameter = 450 MPa 
[n] Hardening Exponent = 0.5 
[SIG_max] Maximum Stress = 425 MPa 
 
Exercise 
 
 
Step 1: Load the RADIOSS User Profile 
1. Launch HyperMesh Desktop. 
2. From the Preferences menu, select the User Profiles or click the icon on toolbar. 
3. Select RADIOSS (Block140) and click OK. 
Step 2: Load the solver deck 
1. Click the Open Model icon to open the fullcar.hm file you saved to your working directory 
from the radioss.zip file. Refer to Accessing the Model Files. 
2. Click Open. 
The model loads into the graphics area. 
Step 3: Create and assign the material for the windshield components 
1. In the Model browser, right-click and select Create > Material. The Entity Editor is displayed 
below the Model browser. 
2. For Name, enter windshield. 
3. Set Card Image as M2_PLAS_JOHNS_ZERIL and click Yes to confirm. 
4. Input the values, as shown below: 
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5. In the Model browser, select components COMP-PSHELL_3 and COMP-PSHELL_16. 
6. Click Mat_Id in the EE, select the material windshield and click OK to update the selected 
components with the created material. 
Step 4: Create and assign the material for the rubber components 
1. In the Model browser, right-click and select Create > Material. The Entity Editor is displayed. 
2. For Name, enter rubber. 
3. Set Card Image to M2_PLAS_JOHNS_ZERIL and click Yes to confirm. 
4. Input the values, as shown below: 
 
5. In the Model browser, select components COMP-PSHELL_20 through COMP-PSHELL_23. 
6. For Mat_Id, select the material rubber and click OK to update the selected components with 
the created material. 
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Step 5: Create Steel material and assign to all other parts 
1. In the Model browser, right-click and select Create > Material. The Entity Editor is displayed. 
2. For Name, enter steel. 
3. Set Card Image to M2_PLAS_JOHNS_ZERIL. 
4. Input the values, as shown below: 
 
5. In the Model browser select all components labeled with COMP-PSHELL and COMP-PROD, 
except COMP-PSHELL_3, COMP-PSHELL_16 and COMP-PSHELL_20 to COMP-PSHELL_23. 
6. For Mat_Id, select the material steel and click OK to assign the material to the selected 
components. 
Step 6: Create a Rigid Wall 
1. In the Model browser, right-click and select Create > Rigid Wall. The Entity Editor is displayed. 
2. For Name, enter ground. 
3. Set Geometry type as Infinite plane. 
4. Click Base node and select 'any node' from the model. 
5. Define the normal vector Z = -1. 
6. Set distance d = 300. 
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7. Go to the Analysis > rigid walls panel. 
8. Move to the geom page. 
9. Click name and select Ground from the list. 
10. Click the edit tab besides base node and change values of the coordinates as indicated below. 
X = -2300, Y = 1200, and Z = -1. 
11. Click update > return. 
Step 7: Create a Cylindrical Rigid Wall to represent pole 
1. In the Model browser, right-click and select Create > Rigid Wall. The Entity Editor will display. 
2. For Name, enter pole. 
3. Set the Geometry type as Cylinder. 
4. Click Base node and select ‘any node’ from the model. 
5. Define the normal vector Z= 1. 
6. For Radius node, do not select anything. Leave it as <Unspecified>. 
7. Set distance d= 1500. 
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8. Go to Analysis > Rigid Walls panel. 
9. Move to the geom page. 
10. Click name and select Pole from the list. 
11. Click the edit tab besides base node and change values of the coordinates as indicated below. 
 X = -320, Y = 1250, and Z = 0. 
12. Set Radius = 250. 
13. Click update > return. 
Step 8: Defining Contact using TYPE 7 interface (Self Contact) 
1. Hide all the 1D (TRUSSES) and 3D (SOLID) parts in the model by going to the Solver browser 
PROP > SHELL, Isolate only. Return to the Model browser. 
2. In the Model browser, right-click and select Create > Contact. The Entity Editor will display. 
3. For Name, enter CAR_CAR. 
4. Set Card Image to TYPE7 and click Yes to confirm. 
5. For Surf_id (M) (master entity), set the option to Components and select displayed 
components and click OK. 
6. Input other parameters, as shown below. 
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Step 9: Defining Contact using TYPE 7 interface between Engine and 
Radiator 
1. In the Solver browser, right-click and select Create > SURF_EXT > PART. 
2. For Name, enter engine. 
3. Click on Componentsand select COMP-PSOLID_24. 
4. In the Model browser, right-click and select Create > Contact. 
5. For Name, enter ENGINE_RADIATOR and set the Card Image as TYPE7 and click Yes to 
confirm. 
6. For Grnod_id (S) (slave entity), set the selector switch to Components and click 
Components, select COMP-PSOLID_26. 
7. For Surf_id (M) (master entity), set the selector switch to Set and click Set, select engine. 
8. Input the values, as shown below: 
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Step 10: Defining initial velocity 
1. Click Tools > BCs Manager to start the BCS Manager. 
2. For Name, enter 35MPH, set Select type as Initial Velocity and set GRNOD to Parts. 
3. Click comps and select all of the parts in the model. 
4. Set the Vx as 15600. 
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5. Click Create to create the boundary condition and boundary condition appears in the table. 
6. Click Close. 
Step 11: Create Time History Nodes 
1. In the Model browser, isolate COMP-PSHELL_19. 
2. Click Tools > Create Cards > TH > NODE. 
3. For Name, enter RAIL and select nodes on the Rail, as shown below. 
 
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4. For NUM_VARIABLES, select 1 and for Data: Var, enter the following: 
 
Step 12: Create output requests and control cards 
1. Launch the HyperMesh Solver browser from View > Browsers > HyperMesh > Solver. 
2. Right-click in the Solver browser general area to create the cards shown below with the given 
values for each parameter: 
Keyword Type Keyword Parameter Parameter Value 
CONTROL CARDS TITLE Status [Checked] 
CONTROL CARDS TITLE TITLE Car_Analysis 
ENGINE KEYWORDS RUN Status [Checked] 
ENGINE KEYWORDS RUN Run Number 1 
ENGINE KEYWORDS RUN Tstop 0.0601 
ENGINE KEYWORDS PRINT Status [Checked] 
ENGINE KEYWORDS PRINT N_Print -1000 
ENGINE KEYWORDS TFILE Status [Checked] 
ENGINE KEYWORDS TFILE Time Frequency 9e-5 
ENGINE KEYWORDS ANIM/ELEM Status [Checked] 
ENGINE KEYWORDS ANIM/ELEM EPSP [Checked] 
ENGINE KEYWORDS ANIM/ELEM VONM [Checked] 
ENGINE KEYWORDS ANIM/ELEM HOURG [Checked] 
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Keyword Type Keyword Parameter Parameter Value 
ENGINE KEYWORDS ANIM/VECT Status [Checked] 
ENGINE KEYWORDS ANIM/VECT VEL [Checked] 
ENGINE KEYWORDS ANIM/VECT CONT [Checked] 
ENGINE KEYWORDS ANIM/VECT FOPT [Checked] 
ENGINE KEYWORDS ANIM/DT Status [Checked] 
ENGINE KEYWORDS ANIM/DT Tstart 0 
ENGINE KEYWORDS ANIM/DT Tfreq 0.003 
Step 13: Export the model 
1. Click File > Export or click the Export icon . 
2. Enter a filename in the destination directory where you want to export to. 
3. Enter the name FULLCAR and click Save. 
4. Click the downward-pointing arrows next to Export options to expand the panel. 
5. Click Merge starter and engine file to export the engine file with the model in one file. 
6. Click Export to export both model and engine file. 
Step 14: Run the solver using RADIOSS Manager 
1. Go to Start > Programs > Altair HyperWorks 2017 > RADIOSS. 
2. For Input file, browse to the exercise folder and select the file FULLCAR_0000.rad. 
 
Step 15 (Optional): View the results in HyperView 
The exercise is complete. Save your work to a HyperMesh file. 
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RD-3560: Bottle Drop 
This tutorial demonstrates how to simulate a Bottle Drop Test containing water and air. The 
objective is to evaluate the diffusivity of water and air in the bottle on drop. 
 
Exercise 
 
 
Step 1: Load the RADIOSS User Profile 
1. Launch HyperMesh Desktop. 
2. From the Preferences menu, select the User Profiles or click the icon in toolbar. 
3. Select RADIOSS (Block140) and click OK. 
Step 2: Load the bottle.hm file 
1. Click the Open Model icon to open the bottle.hm file you saved to your working directory 
from the radioss.zip file. Refer to Accessing the Model Files. 
2. Click Open. The model loads into the graphics area. 
 
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Step 3: Define Materials for Air and Water 
1. In the Model browser, right-click and select Create > Material. The Entity Editor is displayed 
below the Model browser. 
2. For Name, enter Air. 
3. For Card Image, select M37_BIPHAS and click Yes to confirm. 
4. Input the values, as shown below. Remember to select ALE under ALE CFD Formulation. 
 
5. Similarly create a material with the name Water using Steps 3.1 to 3.4. 
6. Input the values, as shown below. 
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Step 4: Load stress-strain curve from a file 
To create the material for bottle (plastic) you need a stress strain curve that is available in a file 
from test. 
1. Click XYPlots > Create > Plots. 
2. Enter the plot= name as stress-strain and click create plot > return. 
3. Click XYPlots > Edit > Curves. 
4. Toggle the create radio button. 
5. Click the load button to load the stressstrain_curve.txt file. 
6. With the x radio button selected, click the green + to the right of comp= and set it to x. 
7. Select the y radio button, click the green + to the right of comp= and set it to y. 
8. Click create > return. 
 
9. In the Model browser, click on curve. 
10. In the Entity Editor, rename it as stress_strain. The data in the file is loaded as a curve in 
HyperMesh. 
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Step 5: Define Material for Bottle 
1. In the Model browser, right-click and select Create > Material. The Entity Editor is displayed 
below the Model browser. 
2. For Name, enter Bottle. 
3. For Card Image, select M36_PLAS_TAB and click Yes to confirm. 
4. Input the values, as shown below: 
 
Select the stress-strain curve created for fct_ID1. 
Step 6: Define property and assign material for Air 
1. In the Model browser, right-click and select Create > Property. 
2. For Name, enter Air. 
3. For Card Image, select P14_SOLID and click Yes to confirm. 
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4. Enter parameters, as shown below. 
 
5. In the Model browser, click on the air component. 
6. Select material and property created for Air in the Entity Editor. 
Step 7: Define property and assign material for Water 
1. In the Model browser, right-click and select Create > Property. 
2. For Name, enter Water. 
3. For Card Image, select P14_SOLID and click Yes to confirm. 
4. Enter parameters, as shown below. 
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5. In the Model browser, click on the water component. 
6. Select material and property created for Water in the Entity Editor. 
Step 8: Define property and assign material for Bottle 
1. In the Model browser, right-click and select Create > Property. 
2. For Name, enter Bottle. 
3. For Card Image, select P1_SHELL. 
4. Enter parameters, as shown below. 
N = 5 
Thick = 0.3 
5. In the Model browser, click on the bottle component. 
6. Select material and property created for Bottle in the Entity Editor. 
 
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Step 9: Define an Interface between Bottle and Water 
1. In the Model browser, right-click and select Create > Set. 
2. For Name, enter ALE_Surf. 
3. Set Card Image to SURF_EXT and click Yes to confirm. 
4. For Entity IDs, set the entity selector to Components. 
5. Click Components and select water and air. 
6. Click OK to complete the selection. 
 
7. In theModel browser, right-click and select Create > Contact. 
8. For Name, enter Bottle_Water, and for Card Image, select TYPE1. 
9. For ls2(S) (slave entity), set the selector to Set. 
10. In the Select Set dialog, select ALE_surf and click OK. 
11. For ls1(M) (master entity), set the selector to Components. 
12. In the Select Components dialog, select Bottle and click OK. 
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Step 10: Create Initial Velocity for Bottle 
1. Click Tools > BCs Manager. 
2. Set the Select type to Initial Velocity. 
3. For Name, enter Bottle. 
4. Click Parts and bottle. 
5. Set the Vz velocity to -5468.200 (Negative direction indicating opposite to Global Z-axis). 
6. Click Create to create the imposed velocity boundary condition. 
 
Step 11: Create Initial Velocity for Water and Air 
1. Set the Select type to Initial Velocity. 
2. For Name, enter Liquid. 
3. Click Parts and select water and air. 
4. Set the Vz velocity to -5468.200 (Negative direction indicating opposite to Global Z-axis). 
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5. Click Create to create the imposed velocity boundary condition. 
6. Select the Liquid initial velocity in the table, right-click and select Card Edit. 
7. Change the Type to T+G and click return to complete the definition. 
 
Step 12: Create Rigid Wall 
1. In the graphics area, press the F8 key, and create the node at the coordinates: X= 0, Y= 0, Z= 
-50 and create node. 
2. In the Model browser, right-click and select Create > Rigid Wall. 
3. For Name, enter GROUND with Geometry type as Infinite plane. 
4. Select node created in Step 12.1 as base node and make sure the normal vector is in the z-
direction, as shown below. 
5. Set the d to 250.0. 
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\ 
Step 13: Create output requests and control cards 
1. Launch the HyperMesh Solver browser from View > Browsers > HyperMesh > Solver. 
2. Right-click in the Solver browser general area to create the cards, shown below with the given 
values for each parameter: 
Keyword Type Keyword Parameter Parameter Value 
CONTROL CARDS TITLE Status [Checked] 
CONTROL CARDS TITLE TITLE Bottle_drop 
CONTROL CARDS MEMORY Status [Checked] 
CONTROL CARDS MEMORY NMOTS 40000 
CONTROL CARDS SPMD Status [Checked] 
CONTROL CARDS IOFLAG Status [Checked] 
CONTROL CARDS ANALY Status [Checked] 
ALE-CFD-SPH ALE_CFD_SPH_CARD Status [Checked] 
ALE-CFD-SPH ALE_CFD_SPH_CARD ALE_Grid_Velocity [Checked –] 
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Keyword Type Keyword Parameter Parameter Value 
ENGINE KEYWORDS RUN Status [Checked] 
ENGINE KEYWORDS RUN Tstop 1.5e-2 
ENGINE KEYWORDS PARITH Status [Checked] 
ENGINE KEYWORDS PARITH Keyword2 OFF 
ENGINE KEYWORDS PRINT Status [Checked] 
ENGINE KEYWORDS PRINT N_Print -1000 
ENGINE KEYWORDS TFILE Status [Checked] 
ENGINE KEYWORDS TFILE Time Frequency 0.00015 
ENGINE KEYWORDS ANIM > ANIM/ELEM Status [Checked] 
ENGINE KEYWORDS ANIM > ANIM/ELEM VONM [Checked] 
ENGINE KEYWORDS ANIM > ANIM/ELEM PRES [Checked] 
ENGINE KEYWORDS ANIM > ANIM/DT Status [Checked] 
ENGINE KEYWORDS ANIM > ANIM/DT Tstart 0 
ENGINE KEYWORDS ANIM > ANIM/DT Tfreq 1.5e-3 
ENGINE KEYWORDS DT > DT Status [Checked] 
ENGINE KEYWORDS DT > DT Tscale 0.5 
ENGINE KEYWORDS DT > DT Tmin 0.0 
Step 14: Export the model 
1. Click File > Export Solver Deck or click the Export Solver Deck icon . 
2. For File:, click the folder icon and navigate to the destination directory where you want to 
export to. 
3. For Name, enter bottle and click Save. 
4. Click the downward-pointing arrows next to Export options to expand the panel. 
5. Click Merge starter and engine file to export all the data in one file (or export separately). 
6. Click Export to export solver deck. 
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Step 15: Run the solver using RADIOSS Manager 
1. Go to Start > Programs > Altair HyperWorks 2017 > RADIOSS. 
2. For Input file, browse to the exercise folder and select the file bottle_0000.rad. 
 
Step 16 (Optional): View the results in HyperView 
The exercise is complete. Save your work to a HyperMesh file. 
 
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RD-3580: Boat Ditching 
 
Boat Ditching with Boundary Elements 
The objective of this tutorial is to simulate Boat Ditching with Boundary Elements to represent 
continuous water using bi-phase material law (Law 37). In this model, the top chamber is air, lower 
chamber is water surrounded by boundary elements. Law 37 is used for air, water and boundary. 
Boundary conditions are applied on each surface of boundary in the normal direction. An interface 
between fluid and boat (CEL) is defined to manage the contact. 
 
Exercise 
 
 
Step 1: Load the RADIOSS (Block) User Profile 
1. Launch HyperMesh Desktop. 
2. From the Preferences menu, select the User Profiles or click the icon in toolbar. 
3. Select RADIOSS (Block140) and click OK. 
Step 2: Load the boat_ditching_1.hm file 
1. From the toolbar, click the Open Model icon to open the boat_ditching_1.hm file you saved 
to your working directory from the radioss.zip file. Refer to Accessing the Model Files. 
2. Click Open. The model loads into the graphics area. 
Step 3: Define and assign Material, Property to component AIR 
1. In the Model browser, right-click and select Create > Material. The new material shows up in 
the Entity Editor (EE). 
2. For Name, enter air. 
3. For Card Image, select M37_BIPHAS. 
4. Input the values, as shown below. 
Remember to select ALE under ALE CFD Formulation. 
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5. Create a new property named Air with a Card Image of P14_SOLID by right-clicking in the 
Model browser. 
6. Click on the component Air and assign Air as the Prop_Id and air as the Mat_Id in the Entity 
Editor. 
Step 4: Define and assign Material, Property to component WATER 
1. In the Model browser, right-click and select Create > Material. The new material shows up in 
the Entity Editor (EE). 
2. For Name, enter water. 
3. For Card Image, select M37_BIPHAS. 
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4. Input the values, as shown below. 
Remember to select ALE under ALE CFD Formulation. 
 
5. In the Model browser, create a new property named Water with a Card Image of P14_SOLID. 
6. Click on the component Water and assign Water as the Prop_Id and water as the Mat_Id in 
the Entity Editor. 
Step 5: Define and assign Material, Property to component BOAT 
1. In the Model browser, right-click and select Create > Material. The new material shows up in 
the Entity Editor (EE). 
2. For Name, enter boat. 
3. For Card Image, select M1_ELAST. 
4. Input the values, as shown below: 
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5. In the Model browser, create a new property named Boat with a Card Image of P1_SHELL and 
assign the new property with the values shown below: 
 
6. Click on the component Boat and assign Boat as the Prop_Id and boat as the Mat_Id in the 
Entity Editor. 
Step 6: Define and assign Material, Property to component Air-BC 
1. In the Model browser, right-click and select Create > Material. The new material shows up in 
the Entity Editor. 
2. For Name, enter air-bc. 
3. For Card Image, select M37_BIPHAS. 
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4. Input the values, as shown below. 
Remember to select ALE underALE CFD Formulation. 
 
5. Click on the component Air-BC and assign Air as the Prop_Id and air-bc as the Mat_Id in 
the Entity Editor. 
Step 7: Define and assign Material, Property to component Water-BC 
1. In the Model browser, right-click and select Create > Material. The new material shows up in 
the Entity Editor. 
2. For Name, enter water-bc. 
3. For Card Image, select M37_BIPHAS. 
4. Input the values, as shown below. 
Remember to select ALE under ALE CFD Formulation. 
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5. Click on the component Water-BC and assign Water as the Prop_Id and water-bc as the 
Mat_Id in the Entity Editor. 
Step 8: Define an Interface between Boat and Fluid 
1. Click Tools > Create Cards > ALE-CFD-SPH > INTER_TYPE18. The new interface opens in 
the Entity Editor. 
2. For Name, enter Boat-Fluid. 
3. Enter the parameter values, as shown below for Stfval and GAP. 
 
4. Set the Surf_id (M) for master selection to Components and select the boat component. 
5. Set the Grnod_id (S) for slave selection to Components and select all the components, except 
boat. 
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Step 9: Create RBODY for the Boat and assign mass to the Master Node 
1. Isolate the boat part using the Model browser. 
2. From the pull-down menu, select Tools > Rbody Manager. 
3. For Title:, enter RIGID-BOAT, verify that Master node: is set to Calculate Node and set Slave 
node(s): to Parts and select the Boat. 
 
4. Click Create to create the RBODY. The created RBODY appears in the table. 
5. Select the created RBODY in the table and right-click and select Edit card to open the card 
image panel. 
6. Assign a mass of 23.04 kg to the boat. 
7. Click return to return from the card image panel. 
8. Click Close to close the RBODY Manager. 
Step 10: Create Initial Velocity 
1. Click Tools > BCs Manager. 
2. For Name, enter Boat. 
3. For Select type, select Initial Velocity. 
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4. Set GRNOD to Nodes. 
5. Click the Node tab and select the master node of the RBODY created in the previous step. 
6. Set Z velocity (VZ) to -11.0 indicating velocity opposite to global Z-axis. 
7. Click Create to create the initial velocity boundary condition. 
 
Step 11: Create Boundary Conditions on outermost faces 
1. In the Model browser, right-click on the Components sub-folder and select Show to display all 
components. 
2. Enter a new boundary condition in the BCs Manager named Constraint-x. 
3. For Select type, select Boundary condition. 
4. Set GRNOD to Nodes. 
5. Click the Node tab and select a node on both faces normal to x-axis. 
6. Then click the nodes yellow tab and select By face. 
HyperMesh will automatically select nodes on the face, as shown in figure. 
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7. Check Tx box to constraint translation in X direction. 
8. Click Create to create the constraint. 
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9. Follow the same procedure (step 1-8) but create constraint in Y direction on the sides parallel to 
Y plane of global axis. 
10. Follow the same procedure (step 1-8) but create constraint in Z direction on the sides parallel to 
Z plane of global axis. 
Step 12: Creating control cards and output requests 
1. Launch the HyperMesh Solver browser from View > Browsers > HyperMesh > Solver. 
2. Right-click in the Solver browser general area to create the cards shown below with the given 
values for each parameter: 
Keyword Type Keyword Parameter Parameter Value 
CONTROL CARDS TITLE Status [Checked] 
CONTROL CARDS TITLE TITLE Boat-Ditch-1 
CONTROL CARDS MEMORY Status [Checked] 
CONTROL CARDS MEMORY NMOTS 40000 
CONTROL CARDS SPMD Status [Checked] 
CONTROL CARDS IOFLAG Status [Checked] 
CONTROL CARDS ANALY Status [Checked] 
ALE-CFD-SPH ALE_CFD_SPH_CARD Status [Checked] 
ALE-CFD-SPH ALE_CFD_SPH_CARD ALE_Grid_Velocity [Checked] 
ENGINE KEYWORDS RUN Status [Checked] 
ENGINE KEYWORDS RUN RunName Boat-Ditch-1 
ENGINE KEYWORDS RUN Tstop 30.01 
ENGINE KEYWORDS PARITH Status [Checked] 
ENGINE KEYWORDS PARITH Keyword2 OFF 
ENGINE KEYWORDS PRINT Status [Checked] 
ENGINE KEYWORDS PRINT N_Print -1000 
ENGINE KEYWORDS ANIM/ELEM Status [Checked] 
ENGINE KEYWORDS ANIM/ELEM VONM [Checked] 
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Keyword Type Keyword Parameter Parameter Value 
ENGINE KEYWORDS ANIM/ELEM DENS [Checked] 
ENGINE KEYWORDS ANIM/ELEM PRES [Checked] 
ENGINE KEYWORDS ANIM/VECT Status [Checked] 
ENGINE KEYWORDS ANIM/VECT VEL [Checked] 
ENGINE KEYWORDS ANIM/VECT CONT [Checked] 
ENGINE KEYWORDS ANIM/DT Status [Checked] 
ENGINE KEYWORDS ANIM/DT Tstart 0 
ENGINE KEYWORDS ANIM/DT Tfreq 1.0 
ENGINE KEYWORDS DT > DT Status [Checked] 
ENGINE KEYWORDS DT > DT Tscale 0.5 
ENGINE KEYWORDS DT > DT Tmin 0.0 
Step 13: Export the model 
1. Click File > Export or click the Export icon . 
2. For File:, click the folder icon and navigate to the destination directory where you want to 
export to. 
3. For name, enter boatditching_1 and click Save. 
4. Click the downward-pointing arrows next to Export options to expand the panel. 
5. Click Merge starter and engine file to export one solver deck (or export separately). 
6. Click Export to export solver deck. 
Step 14: Run the solver using RADIOSS Manager 
1. Go to Start > Programs > Altair HyperWorks 2017 > RADIOSS. 
2. For Input file, browse to the exercise folder and select the file boatditching_1_0000.rad. 
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Step 15 (Optional): View the results in HyperView 
The exercise is complete. Save your work to a HyperMesh file. 
 
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Boat Ditching without Boundary Elements 
The objective of this tutorial is to simulate Boat Ditching without Boundary Elements. So there is no 
boundary to represent continuous water. Basically, you are simulating Boat-Ditching in an enclosed 
volume. In this model, the top chamber is air (including its outer layer) and the lower chamber is 
water (including its outer layer). Bi-Phase material Law 37 was used to model air and water. 
Boundary conditions are applied on each surface of boundary in the normal direction. An interface 
between fluid and boat (CEL) is defined to manage the contact. 
 
Exercise 
 
 
Step 1: Load the RADIOSS (Block) User Profile 
1. Launch HyperMesh Desktop. 
2. From the Preferences menu, select the User Profiles or click the icon in toolbar. 
3. Select RADIOSS (Block140) and click OK. 
Step 2: Load the boat_ditching_2.hm file 
1. From the toolbar, click the Open Model icon to open the boat_ditching_2.hm file you saved 
to your working directory from the radioss.zip file. Refer to Accessing the Model Files. 
2. Click Open. The model loads into the graphics area. 
Step 3: Define and assign Material, Property to component AIR 
1. In the Model browser, right-click and select Create > Material. The new material shows in the 
Entity Editor. 
2. For Name, enter air. 
3. For Card Image, select M37_BIPHAS and click Yes to confirm. 
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4. Input the values, as shown below. 
Remember to select ALE under ALE CFD Formulation. 
 
5. In the Model browser, create a new property named Air with a Card Image of P14_SOLID. 
6. Click on the component Air and assign as the Prop_Id and air as the Mat_Id in the Entity 
Editor. 
Step 4: Define and assign Material,Property to component WATER 
1. In the Model browser, right-click and select Create > Material. The new material shows in the 
Entity Editor. 
2. For Name, enter water. 
3. For Card Image, select M37_BIPHAS. 
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4. Input the values, as shown below: 
Remember to select ALE under ALE CFD Formulation. 
 
5. In the Model browser, create a new property named Water with a Card Image of P14_SOLID. 
6. Click on the component Water and assign Water as the Prop_Id and water as the Mat_Id in 
the Entity Editor. 
Step 5: Define and assign Material, Property to component BOAT 
1. In the Model browser, right-click and select Create > Material. The new material shows in the 
Entity Editor. 
2. For Name, enter boat. 
3. For Card Image, select M1_ELAST. 
4. Input the values, as below. 
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5. In the Model browser, create a new property named Boat with a Card Image of P1_SHELL and 
assign the new property with the values shown below: 
 
6. Click on the component Boat and assign Boat as the Prop_Id and boat as the Mat_Id in the 
Entity Editor. 
Step 6: Define an Interface between Boat and Fluid 
1. Click Tools > Create Cards > ALE-CFD-SPH > INTER_TYPE18. The new interface opens in 
the Entity Editor. 
2. For Name, enter Boat-Fluid. 
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3. Enter the parameter values, as shown below for Stfval and GAP. 
 
3. Set the Surf_id (M) for the master selection to Components and select the boat component. 
4. Set the Grnod_id (S) for the slave selection to Components and select all the components, 
except boat. 
Step 7: Create RBODY for the Boat and assign mass to the Master Node 
1. In the Model browser, isolate the boat part. 
2. From the pull-down menu, select Tools > Rbody Manager. 
3. For Title, enter RIGID_BOAT. Verify that the Master node is set to Calculate Node and set the 
Slave node(s) to Parts and select the Boat. 
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4. Click Create to create the RBODY. The created RBODY appears in the table. 
5. Select the created RBODY in the table and click Edit Card to open the Card Image panel. 
6. Assign a mass of 23.04 kg to the boat. 
7. Click return to return from the Card Image panel. 
8. Click Close to close the RBODY Manager. 
Step 8: Create Initial Velocity 
1. Click BCs Manager in the Utility panel or click Tools > BCs Manager. 
2. For Name, enter Boat. 
3. For Select type, select Initial Velocity. 
4. Set GRNOD to Nodes. 
5. Click the Node tab and select the master node of the RBODY created in the previous step (ID: 
690501). 
6. Set Z velocity (VZ) to -11.0, indicating velocity opposite to global Z-axis. 
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7. Click Create to create the initial velocity boundary condition. 
 
Step 9: Create Boundary Conditions on outermost faces 
1. In the Model browser, right-click on the Components subfolder and select Show to display all 
components. 
2. Enter a new boundary condition in the BCs Manager, named Constraint-x. 
3. For Select type, select Boundary Condition. 
4. Set GRNOD to Nodes. 
5. Click the Node selector and select a node on both faces normal to x-axis. 
6. Click the nodes selector and select by face. HyperMesh will automatically select nodes on the 
face, as shown in figure. 
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7. Check Tx box to constraint translation in X direction. 
8. Click Create to create the constraint. 
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9. Follow the same procedure (step 1-8) but create constraint in Y direction on the sides parallel to 
Y plane of global axis. 
10. Follow the same procedure (step 1-8) but create constraint in Z direction on the sides parallel to 
Z plane of global axis. 
Step 10: Creating control cards and output requests 
1. Launch the HyperMesh Solver browser from View > Browsers > HyperMesh > Solver. 
2. Right-click in the Solver browser general area to create the cards shown below with the given 
values for each parameter: 
Keyword Type Keyword Parameter Parameter Value 
CONTROL CARDS TITLE Status [Checked] 
CONTROL CARDS TITLE TITLE Boat-Ditch-2 
CONTROL CARDS MEMORY Status [Checked] 
CONTROL CARDS MEMORY NMOTS 40000 
CONTROL CARDS SPMD Status [Checked] 
CONTROL CARDS IOFLAG Status [Checked] 
CONTROL CARDS ANALY Status [Checked] 
ALE-CFD-SPH ALE_CFD_SPH_CARD Status [Checked] 
ALE-CFD-SPH ALE_CFD_SPH_CARD ALE_Grid_Velocity [Checked] 
ENGINE KEYWORDS RUN Status [Checked] 
ENGINE KEYWORDS RUN RunName Boat-Ditch-2 
ENGINE KEYWORDS RUN Tstop 30.01 
ENGINE KEYWORDS PARITH Status [Checked] 
ENGINE KEYWORDS PARITH Keyword2 OFF 
ENGINE KEYWORDS PRINT Status [Checked] 
ENGINE KEYWORDS PRINT N_Print -1000 
ENGINE KEYWORDS ANIM > ANIM/ELEM Status [Checked] 
ENGINE KEYWORDS ANIM > ANIM/ELEM VONM [Checked] 
ENGINE KEYWORDS ANIM > ANIM/ELEM DENS [Checked] 
ENGINE KEYWORDS ANIM > ANIM/ELEM PRES [Checked] 
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Keyword Type Keyword Parameter Parameter Value 
ENGINE KEYWORDS ANIM > ANIM/VECT Status [Checked] 
ENGINE KEYWORDS ANIM > ANIM/VECT VEL [Checked] 
ENGINE KEYWORDS ANIM > ANIM/VECT CONT [Checked] 
ENGINE KEYWORDS ANIM > ANIM/DT Status [Checked] 
ENGINE KEYWORDS ANIM > ANIM/DT Tstart 0 
ENGINE KEYWORDS ANIM > ANIM/DT Tfreq 1.0 
ENGINE KEYWORDS DT > DT Status [Checked] 
ENGINE KEYWORDS DT > DT Tscale 0.5 
ENGINE KEYWORDS DT > DT Tmin 0.0 
Step 11: Export the model 
1. Click File > Export or click the Export icon . 
2. For File:, click the folder icon and navigate to the destination directory where you want to 
export to. 
3. For name, enter boatditching_2 and click Save. 
4. Click the downward-pointing arrows next to Export options to expand the panel. 
5. Click Merge starter and engine file to export the one solver deck (or export separately). 
6. Click Export to export solver deck. 
Step 12: Run the solver using RADIOSS Manager 
1. Go to Start > Programs > Altair HyperWorks 2017 > RADIOSS. 
2. For Input file, browse to the exercise folder and select the file boatditching_2_0000.rad. 
 
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Step 13 (Optional): View the results in HyperView 
The exercise is complete. Save your work to a HyperMesh file. 
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RD-3590: Fluid Flow through a Rubber Clapper Valve 
The objective of this tutorial is to simulate the flow of water through a rubber valve using an inlet 
option in multi-phase material law (Law 51). In this model the top chamber is air, the lower 
chamber is water, and the bottom row of elements is the inlet. Law 51 is used for air, water and 
inlet. Boundary conditions are applied on each surface of fluid in its normal direction. An interface 
between fluid and rubber (CEL) is defined to manage the contact. 
Exercise 
 
 
Step 1: Load the RADIOSS User Profile 
1. Launch HyperMesh Desktop. 
2. From the Preferences menu, select the User Profiles or click the icon in toolbar. 
3. Select RADIOSS (Block140) and click OK. 
Step 2: Load the valve.hm file 
1. From the toolbar, click the Open Model icon to open the valve.hm file you saved to your 
working directory from the radioss.zip file. Refer to Accessing the Model Files. 
2. Click Open. The model loads into the graphics area. 
Step 3: Creating curves for pressure_inlet1. Launch the HyperMesh Solver browser from View > Browsers > HyperMesh > Solver. 
2. In the Solver browser, right-click and select Create > FUNCT. The Curve editor dialog box 
opens. 
3. In the Curve editor window, click New. 
4. For the Name, enter pressure_inlet and click proceed. 
5. From the Curve editor window, select pressure_inlet from the curve list. 
6. Enter the X and Y coordinates, as shown below. 
 
7. Click Update. 
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8. Follow Steps 3.3 - 3.7 to create a curve named density, with the values shown below. 
 
9. Click Close. 
Step 4: Define and assign Material, Property to component inlet 
1. In the Model browser, right-click and select Create > Material. The new material appears in 
the Entity Editor. 
2. For Name, enter inlet-water. 
3. For Card Image, select MLAW51 and click Yes to confirm. 
4. Input the values, as shown below: 
Remember to select ALE under ALE CFD Formulation. 
 
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5. In the Model browser, right-click and select Create > Property to create a new property. 
6. For Name, enter solids. 
7. For Card Image, select P14_SOLID. Keep all the default settings. 
8. Click Yes to confirm. 
9. In the Model browser, click on the inlet component and assign solids as the Prop_Id and 
inlet-water as the Mat_Id. 
Step 5: Define and assign Material, Property to component Air 
1. In the Model browser, right-click and select Create > Material. The new material appears in 
the Entity Editor. 
2. For Name, enter air. 
3. For Card Image, select MLAW51 and click Yes to confirm. 
4. Input the values, as shown below. 
Remember to select ALE under ALE CFD Formulation. 
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5. Click on the air component in the Model browser and assign solids as the Prop_Id and air as 
the Mat_Id. 
Step 6: Define and assign Material, Property to component Water 
1. In the Model browser, right-click on the material air and click Duplicate. Edit the material 
parameters and table data with the following changes. 
2. Change the Name to water. 
3. Set C0(1) to 1.0e-04. 
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4. Change the value for Alpha(1) to 1.0 and Alpha(2) to 0.0. 
5. Change Rho_Initial to 1.000e-06. 
6. In the Model browser, right-click on the water component and select Assign. Assign solids as 
the Prop_Id and water as the Mat_Id. 
Step 7: Define and assign Material, Property to component Rubber 
1. In the Model browser, right-click and select Create > Material. 
2. For Name, enter rubber. 
3. For Card Image, select M1_ELAST. 
4. Enter the following properties: 
Rho_Initial = 1e-6 kg/mm3 
E = 0.7 
Nu = 0.4 
5. In the Model browser, right-click and select Create > Property. 
6. For Name, enter rubber. 
7. For Card Image, select P14_SOLID. 
8. Set ISOLID to 12. 
9. In the Model browser, right-click on the rubber component and select Assign. Assign rubber 
as the Prop_Id and rubber as the Mat_Id. 
Step 8: Define an Interface between Rubber and Fluid 
1. Open the Solver browser and right-click to select Create > ALE-CFD-SPH > INTER_TYPE18. 
2. For Name, enter rubber-fluid, and for Card Image, select TYPE18. 
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3. To set the Surf_id (M), change the selector to Components and select the rubber component. 
4. To set the Grnod_id (S), change the selector to Components and select all the comps, except 
rubber. 
Step 9: Create Boundary Conditions on outermost faces of solid comps 
1. Click Tools > BCs Manager. 
2. For Name, enter constraint-X, set Select type as Boundary Condition and set the GRNOD 
to Nodes. 
3. Click Nodes and select a node for each outer face parallel to x-axis. 
4. Click Nodes in the panel and select by face. 
HyperMesh will automatically select all nodes in the face. 
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5. Click Create. 
6. Repeat Steps 9.1 to 9.5 to create Boundary conditions on Y and Z faces (see image below for 
reference). 
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7. Check the box Ty in order to constrain the translational d.o.f in Y-direction, as shown below: 
 
Boundary conditions for Y-axis 
8. Check the box next to Tz in order to constrain the translational d.o.f in Z-direction, as shown 
below: 
 
Boundary conditions for Z-axis 
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Step 10: Create Boundary Condition to fix one end of the rubber 
1. For Name, enter Fix-rubber, set Select type to Boundary Condition and set the GRNOD to 
Nodes. 
2. Select all the nodes on the edge of the clapper, as shown below. 
3. Constraint all the translational degree’s of freedom. 
 
4. Click Create to create the constraint. 
 
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Step 11: Create output requests a control card 
1. Launch the HyperMesh Solver browser from View > Browsers > HyperMesh > Solver. 
2. Right-click in the Solver browser general area to create the cards shown below with the given 
values for each parameter: 
Keyword Type Keyword Parameter Parameter 
Value 
CONTROL CARDS TITLE Status [Checked] 
CONTROL CARDS TITLE TITLE CLAPPER 
CONTROL CARDS MEMORY Status [Checked] 
CONTROL CARDS MEMORY NMOTS 40000 
CONTROL CARDS SPMD Status [Checked] 
CONTROL CARDS IOFLAG Status [Checked] 
CONTROL CARDS ANALY Status [Checked] 
ALE-CFD-SPH ALE_CFD_SPH_CARD Status [Checked] 
ALE-CFD-SPH ALE_CFD_SPH_CARD ALE_Grid_Velocity [Checked] 
ALE-CFD-SPH ALE_CFD_SPH_CARD GridVel_Gamma 100.00 
ALE-CFD-SPH ALE_CFD_SPH_CARD GridVel_Cwx 1.00 
ALE-CFD-SPH ALE_CFD_SPH_CARD GridVel_Cwy 1.00 
ENGINE KEYWORDS RUN Status [Checked] 
ENGINE KEYWORDS RUN RunName CLAPPER 
ENGINE KEYWORDS RUN Tstop 50.100 
ENGINE KEYWORDS PARITH Status [Checked] 
ENGINE KEYWORDS PARITH Keyword2 OFF 
ENGINE KEYWORDS PRINT Status [Checked] 
ENGINE KEYWORDS PRINT N_Print -1000 
ENGINE KEYWORDS ANIM/ELEM Status [Checked] 
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Keyword Type Keyword Parameter Parameter 
Value 
ENGINE KEYWORDS ANIM/ELEM VONM [Checked] 
ENGINE KEYWORDS ANIM/ELEM DENS [Checked] 
ENGINE KEYWORDS ANIM/ELEM PRES [Checked] 
ENGINE KEYWORDS ANIM/VECT Status [Checked] 
ENGINE KEYWORDS ANIM/VECT CONT [Checked] 
ENGINE KEYWORDS ANIM/DT Status [Checked] 
ENGINE KEYWORDS ANIM/DT Tstart 0 
ENGINE KEYWORDS ANIM/DT Tfreq 0.5 
ENGINE KEYWORDS DT Status [Checked] 
ENGINE KEYWORDS DT Tscale 0.5 
ENGINE KEYWORDS DT Tmin 0.0 
Step 12: Export the model 
1. Click File > Export or click the Export icon . 
2. For File:, click the folder icon and navigate to the destination directory where you want to 
export to. 
3. For Name, enter clapper and click Save. 
4. Click the downward-pointing arrows next to Export options to expand the panel. 
5. Click Merge starter and engine file to export solver deck as one file (or export separately). 
6. Click on Export to export solver deck. 
Step 13: Run the solver using RADIOSS Manager 
1. Launch Start > Programs > Altair HyperWorks 2017 > RADIOSS. 
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2. For Input file, browse to the exercise folder and select the file clapper_0000.rad. 
 
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RD-3595: Three Point Bending with HyperMesh 
This tutorial demonstrateshow to set up 3-point bending model with symmetric boundary 
conditions in Y direction. 
 
Model Description 
 
 
 UNITS: Length (mm), Time (s), Mass (ton), Force (N) and Stress (MPa) 
 Simulation time: in Engine file [0 – 6.601e-002 s] 
 Only one half of the model is modeled because it is symmetric. 
 The supports are totally fixed. An imposed velocity of 1000 mm/s is applied on the Impactor 
in the (–Z) direction 
 Model size = 370mm x 46.5mm x 159mm 
 Honeycomb Material /MAT/LAW28: HONEYCOMB 
[Rho_I] Initial density = 3.0e-10 ton/mm3 
[E11], [E22] and [E33] Young’s modulus (Eij) = 200 MPa 
[G11], [G22] and [G33] Shear modulus (Gij) = 150 MPa 
 Elasto-Plastic Material /MAT/LAW36: Inner, Outer and Flat 
[Rho_I] Initial density = 7.85-9 ton/mm3 
[E] Young’s modulus = 210000 MPa 
[nu] Poisson's ratio = 0.29 
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 Strain Curve: 
 0 1 2 3 4 5 6 7 8 9 
STRAIN 0 0.012002 0.014003 0.018003 0.022002 0.026003 0.030006 0.032 0.033005 0.033523 
STRESS 325 335.968 343783 349.245 358.649 372.309 383.925 388.109 389.292 389.506 
 
 Elastic Material /MAT/PLAS_JOHNS: Impactor 
[Rho_I] Initial density = 8e-9 ton/mm3 
[E] Young’s modulus = 208000 MPa 
[nu] Poisson's ratio = 0.29 
Exercise 
 
 
Step 1: Load the RADIOSS User Profile 
1. Launch HyperMesh Desktop. 
2. From the Preferences menu, select the User Profiles or click the icon in toolbar. 
3. Select RADIOSS (Block140) and click OK. 
Step 2: Retrieve the RADIOSS file 
1. Click File > Import > Solver Deck or click . 
2. Click the Select File icon to open the BENDING_0000.rad file you saved to your working 
directory from the radioss.zip file. Refer to Accessing the Model Files. 
3. Click Import. 
4. Click Close to close the window. 
Step 3: Create and Assign material and property for HCFOAM 
1. In the Model browser, right-click and select Create > Material. The new material appears in 
the Entity Editor. 
2. For Name, enter Foam. 
3. For Card Image, select M28_HONEYCOMB and click Yes to confirm. 
4. Input values, as shown below: 
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5. In the Model browser, right-click and select Create > Property to create a new property. 
6. For Name, enter Foam and set the new property Card Image as P14_SOLID. Leave all the 
settings as default, except for ISOLID which should be set to 24. 
7. In the Model browser, right-click on the component HCFoam and select Assign. Assign Foam as 
the Prop_Id and Foam as the Mat_Id. 
8. Click Apply. 
 
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Step 4: Create and Assign material and property for the component Inner 
1. In the Model browser, right-click and select Create > Material. The new material appears in 
the Entity Editor. 
2. For Name, enter Inner. 
3. For Card Image, select M36_PLAS_TAB and click Yes to confirm. 
4. Input the values, as shown below: 
 
5. In the Model browser, right-click and select Create > Property to create a new property. 
6. For Name, enter Inner and set Card Image as P1_SHELL. Leave all the settings as default, 
except for Ishell which should be set to 4 and Thick which should be set to 9.119e-01. 
7. In the Model browser, right-click on the component Inner and select Assign. Assign Inner as 
the Prop_Id and Inner as the Mat_Id. 
Step 5: Create and Assign material and property for the component Outer 
1. In the Model browser, right-click on the material Inner and select Duplicate. Name the new 
material Outer. This creates a new material that is identical to the source material. 
2. In the Model browser, right-click on the property Inner and select Duplicate. Name the new 
property Outer. This creates a new property that is identical to the source property. 
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3. In the Model browser, right-click on the component Outer and select Assign. Assign Outer as 
the Prop_Id and Outer as the Mat_Id. 
Step 6: Create and Assign material and property for the component Flat 
Follow the procedure described in Step 5 with Outer replaced by Flat. 
Step 7: Create and assign material and property for Impactor 
1. In the Model browser, right-click and select Create > Material. The new material shows up in 
the Entity Editor. 
2. For Name, enter Impactor. 
3. For Card Image, select M1_ELAST. 
4. Input the values, as shown below: 
 
5. In the Model browser, right-click on the property Inner and select Duplicate. Name the new 
property Impactor. This creates a new property that is identical to the source property. 
6. In the Model browser, right-click on the component Impactor and select Assign. Assign 
Impactor as the Prop_Id and Impactor as the Mat_Id. 
Step 8: Create and assign material and property for Support 
Follow the same procedures as in Step 5. Create a copy of Impactor property and material with 
name support and assign it to component support. 
Step 9: Create a rigid body to make Impactor and Support Rigid 
1. In the Model browser, right-click and select Create > Component. 
2. For Name, enter Impact rigid. 
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3. Select any color for easy visualization. 
4. Set Card Image to None. 
5. Go to the 1D page, select the rigids panel. 
6. Verify that you are in the create subpanel. 
7. For dependent switch to comps. 
8. For primary node switch to calculate node. 
9. Click comps. 
10. Select Impactor, then click select. 
11. Click create. 
12. Click return to exit the panel. 
13. Similarly, create rigid body for Support component in a collector with the name “Support 
rigid” using Steps 9.1 to 9.12. 
 
Step 10: Define imposed velocity and boundary condition for the impactor 
1. From the Utility page, start the BCs Manager. 
2. For Name, enter IMPOSED_VELOCITY, set Select type to Imposed Velocity and set the 
GRNOD to Nodes. 
3. Click nodes and select the master node of the rigid body of the Impactor, as shown in the 
following image. 
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4. Set the Direction as Z. 
5. Set Scale Y to -1000.0 as the direction of velocity is opposite to the global Z-axis. 
6. Set the Curve ID to Select curve. 
7. Select the predefined curve to Func1. 
8. Click create to create the imposed velocity. 
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9. For Name, enter Impactor_constraints, set Select type to Boundary Condition and set the 
GRNOD to Nodes. 
10. Click nodes and select the master node of the rigid body. 
11. Check all the degrees of freedom to constrain, except Tz. 
12. Click create to create the boundary condition. 
Step 11: Define fixed boundary condition for the support 
1. From the Utility page, start the BCs Manager. 
2. For Name, enter Support_fixed, set Select type to Boundary Condition and set the GRNOD 
to Nodes. 
3. Select the master node of the rigid body created on Supporter, as shown in the following 
image. 
4. Check all the degrees of freedom. 
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5. Click create to create the boundary condition. 
 
 
Step 12: Define symmetry boundary condition for the foam, inner, outer 
and flat 
1. From the Utility page, start the BCs Manager. 
2. For Name, enter SYMMETRY_XZ, set Select type to Boundary Condition and set the GRNOD to 
Nodes. 
3. Select the nodes of the foam, inner, outer and flat, as shown in the following image. 
4. Check the degrees of translational degrees of freedom Y and rotational degrees of freedom X 
and Z to constraint. 
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5. Click create to create the boundary condition. 
 
 
6. Click close to exit the BC Manager. 
Step 13: Define contacts between the beam and the support 
1. Launch the HyperMesh Solver browser from View > Browsers > HyperMesh > Solver. 
2. In the Solver browser, right-click and select Create > INTER > TYPE7. 
3. Enter the values, as shown below: 
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4. Set the Surf_id (M) for the master selection to Components and select the Support 
component. 
5. Set the Grnod_id (S) for the slave selection to Components and select the Flat component. 
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6. Similarly create the contact for Impactor with Outer, as shown below. 
 
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Step 14: Define the self contact between the beam components 
1. Using the directions in Step 13, create a new Type 7 interface named Self with the components 
Outer, Inner, and Flat as Master and the same components Outer, Inner, and Flat as Slave. 
This will make the components self-contact instead of self-penetrate. Verify that the interface 
has a Fric of 0.1 and Gapmin of 0.2. 
 
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Step 15: Create Interface time history 
1. Right-click in the Solver browser and select Create > TH > INTER. 
2. For Name, enter IMPACTOR. 
3. Switch the entity selector to groups. 
4. Click groups and select the interfaces Impactor and Support from the list. 
5. Click OK. 
6. Set NUM_VARIABLES to 1 and Data: Var to DEF. 
 
Step 16: Creating control cards and output requests 
1. Launch the HyperMesh Solver browser from View > Browsers > HyperMesh > Solver. 
2. Right-click in the Solver browser general area to create the cards shown below with the given 
values for each parameter: 
Keyword Type Keyword Parameter Parameter Value 
CONTROL CARDS TITLE Status [Checked] 
CONTROL CARDS TITLE TITLE 3PBENDING 
ENGINE KEYWORDS RUN Status [Checked] 
ENGINE KEYWORDS RUN RunName 3PBENDING 
ENGINE KEYWORDS RUN RunNumber 1 
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Keyword Type Keyword Parameter Parameter Value 
ENGINE KEYWORDS RUN Tstop 7.01e-2 
ENGINE KEYWORDS TFILE Status [Checked] 
ENGINE KEYWORDS TFILE Time_frequency 0.0001 
ENGINE KEYWORDS PRINT Status [Checked] 
ENGINE KEYWORDS PRINT N_Print -100 
ENGINE KEYWORDS ANIM/ELEM Status [Checked] 
ENGINE KEYWORDS ANIM/ELEM VONM [Checked] 
ENGINE KEYWORDS ANIM/ELEM EPSP [Checked] 
ENGINE KEYWORDS ANIM/VECT Status [Checked] 
ENGINE KEYWORDS ANIM/VECT VEL [Checked] 
ENGINE KEYWORDS ANIM/VECT CONT [Checked] 
ENGINE KEYWORDS ANIM/DT Status [Checked] 
ENGINE KEYWORDS ANIM/DT Tstart 0 
ENGINE KEYWORDS ANIM/DT Tfreq 2.5e-3 
ENGINE KEYWORDS DT Status [Checked] 
ENGINE KEYWORDS DT Tscale 0.0 
ENGINE KEYWORDS DT Tmin 0.0 
ENGINE KEYWORDS DT/NODA Status [Checked] 
ENGINE KEYWORDS DT/NODA CST_0 [Checked] 
ENGINE KEYWORDS DT/NODA/CST_0 Tscale 0.9 
ENGINE KEYWORDS DT/NODA/CST_0 Tmin 7e-7 
ENGINE KEYWORDS DT/NODA DEL [Checked] 
ENGINE KEYWORDS DT/NODA/DEL Tscale 0.9 
ENGINE KEYWORDS DT/NODA/DEL Tmin 3.5e-8 
ENGINE KEYWORDS RBODY_ENGINE 
RBODY/ON 
Status [Checked] 
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Keyword Type Keyword Parameter Parameter Value 
ENGINE KEYWORDS RBODY_ENGINE NUM_rbnodes 2 
ENGINE KEYWORDS RBODY_ENGINE Data: Nodes 29664 
29665 
Step 17: Export the model 
1. Click File > Export or click the Export icon . 
2. For File:, navigate to the destination directory where you want to export to. 
3. For name, enter 3BENDING and click Save. 
4. Click the downward-pointing arrows next to Export options to expand the panel. 
5. Click Merge starter and engine file to export solver deck as one file (or export separately). 
6. Click on Export to export solver deck. 
Step 18: Open RADIOSS Manager 
1. Go to Start > Programs > Altair HyperWorks 2017 > RADIOSS. 
2. For Input file, browse to the exercise folder and select the file 3PBENDING_0000.rad. 
 
Step 19: Review the listing files for this run and verify on the results 
1. See if there are any warnings or errors in .out files. 
2. Using HyperView, plot the displacement, strain contour and vectors. 
 
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Exercise Expected Results 
 
 
 
von Mises Stress Contour (MPa) 
 
Plastic Strain Contour 
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Contact Force for Impactor Interface 
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RD-3597: Cell Phone Drop Test using HyperMesh 
This tutorial demonstrates how to simulate a free fall of a cell phone due to gravity from a height of 
1001mm using 2nd order tetra elements. 
 
Model Description 
 
 
 UNITS: Length (mm), Time (s), Mass (ton), Force (N) and Stress (MPa) 
 Simulation time: in Engine [0 – 3.3e-3] 
 This is a very simple cell phone model used to demonstrate how to set up a drop test. The 
model is an assembly of two solid parts meshed with Tetra 10 elements, connected with 
spring elements, and contact defined between them. 
 To reduce the simulation time, the cell phone is dropped 1 mm from the ground with an initial 
velocity of -4429.4469 mm/s representing the velocity that it would have attained from a free 
fall of 1000 mm. 
 Boundary Conditions: Gravity load + initial velocity of -4429.4469 mm/s on the cell phone. 
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 Elasto-plastic Material /MAT/LAW36 (Plastic) 
[Rho_I] Initial density = 1.16E-9 ton/mm3 
[nu] Poisson's ratio = 0.3 
[E] Young's modulus = 1000 MPa 
STRAIN 0 16 
STRESS 1 17 
Exercise 
 
 
Step 1: Load the RADIOSS User Profile 
1. Launch HyperMesh Desktop. 
2. From the Preferences menu, select the User Profiles or click the icon in toolbar. 
3. Select RADIOSS (Block140) and click OK. 
Step 2: Load the cellphone.hm file 
1. From the toolbar, click the Open Model icon to open the cellphone.hm file you saved to 
your working directory from the radioss.zip file. Refer to Accessing the Model Files. 
2. Click Open. The model loads into the graphics area. 
Step 3: Creating the material curve 
1. Click XYPlots > Curve Editor. 
2. In the Curve editor window, click New. 
3. For the curve name, enter stress_strain_curve. 
4. Click proceed. 
5. From the Curve editor window, select stress_strain_curve from the Curve List. 
6. Enter the X and Y coordinates, as shown below. 
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7. Click Update > Close. 
Step 4: Create material and properties for the cell phone parts 
1. In the Model browser, right-click and select Create > Material to create a new material. 
2. For Name, enter cell_phone. 
3. For Card Image, select M36_PLAS_TAB and click Yes in the confirmation window. 
4. Input the values, as shown below. 
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5. Select N_func and set to 1. 
6. Click fct_ID1 and select stress_strain_curve (the function curve previously created). 
7. In the Model browser, right-click and select Create > Property to create a property. 
8. For Name, enter cell_phone. 
9. For Card Image, select P14_SOLID and click Yes to confirm. 
10. Set the variable I_tetra to a value of 1. 
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11. In the Model browser, expand the Components folder and highlight the components 
Cellphone_bottom and Cellphone_top and right-click to Assign (or use the Entity Editor) the 
newly created property and material. 
Step 5: Create property for the spring links 
1. In the Model browser, right-click and select Create > Property to create a new property. 
2. For Name, enter spring. 
3. Set Card Image to P13_SPR_BEAM and click Yes to confirm. 
4. Enter the following values: 
Mass (MASS): 2e-6 ton 
Inertia (Inertia): 2e-4 mm4 
Translation stiffness (K_Tensn, K_ShrY, and K_ShrZ): 50 
Rotation stiffness (K_Tor, K_FlxY, and K_FlxZ): 100N 
5. Click return to return to component panel. 
6. In the Model browser, select the component Connection_springs and right-click Assign (or 
use the Entity Editor) to assign the newly created property to the spring component. 
Step 6: Define the Interface between cell phone parts 
1. In the Model browser, right-click and select Create > Contact Surface. 
2. For Name, enter self. 
3. Click on Elements. 
4. Switch from add shell elements to add solid faces. 
5. Select elements by collector and select Cellphone_bottom and click select. 
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6. For face nodes, select nodes by collector and select cellphone bottom and click select > 
add > return. 
7. In the Model browser, right-click and select Create > Contact. 
8. For Name, enter Self. 
9. Set Card Image to TYPE7 and click Yes to confirm. 
10. For Grnod_id (S), select nodes > by collector and select Cellphone_top and click select > 
add and click return. 
11. For Surf_id (M), switch to Contactsurf, click on Contactsurf and select self. 
12. Click OK. 
13. Set Fric to 0.1. 
14. Set Gapmin to 0.3. 
 
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Step 7: Create a rigid wall 
1. In the Model browser, right-click and select Create > Rigid Wall. 
2. For Name, enter GROUND. 
3. Set the Geometry type to Infinite plane. 
4. Click in the graphics area and press the F8 key on the keyboard. Enter the node coordinates: 
X=0, Y=0, and Z=19. 
5. Click create. 
6. Click return to exit the panel. 
7. In the Entity Editor, select the created node as Base node. 
8. Make sure the normal vector is set to z-axis, as shown below. 
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9. For d, enter 50. 
10. To review, go to the Solver browser, select the RWALL folder. 
11. Right-click on GROUND and click Review. 
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12. Click return to exit from the panel. 
Step 8: Define gravity load 
1. In the Model browser, right-click and select Create > Set. 
2. For Name, enter Gravity, set Card Image as GRNOD and click Yes to confirm. 
3. Select Nodes of all three parts. 
4. In the Model browser, right-click and select Create > Load Collector. 
5. For Name, enter loadcol1, set Card Image as GRAV_Collector and click Yes to confirm. 
6. Set Direction to Z. 
7. For Grnod_id, select Gravity from the Select Set dialog and click OK. 
8. Set scale_y to -9810.0 indicating gravity in opposite Z direction. 
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9. From the XYPlots pull-down, click Curve Editor. 
10. In the Curve editor window, click New. 
11. For Name =, enter gravity. 
12. Click proceed. 
13. In the Curve editor window, select gravity from the Curve List. 
14. Enter X and Y, as shown in the following image: 
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15. Click Update > Close to close the Curve editor window. 
16. Back in Gravity load collector, update Ifunc to the curve just created. 
Step 9: Apply an initial velocity to the Cell Phone 
1. In the Model browser, right-click and select Create > Load Collector. 
2. For Name, enter Initial_velocity, set Card Image to INIVEL_Collector. 
3. For Grnod_id, select the same set (Gravity) previously used. 
4. For Vz =, enter the value -4429.4469. 
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Step 10: Creating output request and control cards 
1. Launch the HyperMesh Solver browser from View > Browsers > HyperMesh > Solver. 
2. Right-click in the Solver browser general area to create the cards shown below with the given 
values for each parameter: 
Keyword Type Keyword Parameter Parameter Value 
CONTROL CARDS TITLE Status [Checked] 
CONTROL CARDS TITLE TITLE Cellphone_drop 
CONTROL CARDS MEMORY Status [Checked] 
CONTROL CARDS MEMORY NMOTS 40000 Not needed 
CONTROL CARDS SPMD Status [Checked] 
CONTROL CARDS IOFLAG Status [Checked] 
CONTROL CARDS ANALY Status [Checked] 
ALE-CFD-SPH ALE_CFD_SPH_CARD Status [Checked] 
ALE-CFD-SPH ALE_CFD_SPH_CARD ALE_Grid_Velocity [Checked] 
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Keyword Type Keyword Parameter Parameter Value 
ALE-CFD-SPH ALE_CFD_SPH_CARD GridVel_Gamma 100.00 
ENGINE KEYWORDS RUN Status [Checked] 
ENGINE KEYWORDS RUN Tstop 3e-3 
ENGINE KEYWORDS PARITH Status [Checked] 
ENGINE KEYWORDS PARITH Keyword2 ON 
ENGINE KEYWORDS PRINT Status [Checked] 
ENGINE KEYWORDS PRINT N_Print -1000 
ENGINE KEYWORDS ANIM/ELEM Status [Checked] 
ENGINE KEYWORDS ANIM/ELEM VONM [Checked] 
ENGINE KEYWORDS ANIM/ELEM DENS [Checked] 
ENGINE KEYWORDS ANIM/ELEM PRES [Checked] 
ENGINE KEYWORDS ANIM/ELEM EPSP [Checked] 
ENGINE KEYWORDS ANIM/VECT Status [Checked] 
ENGINE KEYWORDS ANIM/VECT CONT [Checked] 
ENGINE KEYWORDS ANIM/DT Status [Checked] 
ENGINE KEYWORDS ANIM/DT Tstart 0.0 
ENGINE KEYWORDS ANIM/DT Tfreq 2e-4 
ENGINE KEYWORDS DT Status [Checked] 
ENGINE KEYWORDS DT Tscale 0.0 
ENGINE KEYWORDS DT Tmin 0.0 
Step 11: Export the model 
1. Click File > Export or click the Export Solver Deck icon . 
2. For File:, navigate to the destination directory where you want to export to. 
3. For Name, enter Cellphone and click Save. 
4. Click the downward-pointing arrows next to Export options to expand the panel. 
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5. Click Merge starter and engine file to export solver deck as one file (or export separately). 
6. Click on Export to export solver deck. 
Step 12: Open RADIOSS Manager from windows Start menu 
1. Go to Start > Programs > Altair HyperWorks 2017 > RADIOSS. 
2. For Input file(s), browse to the exercise folder and select the file cellphone_0000.rad. 
 
Step 13: Review the listing files for this run and verify on the results 
1. See if there are any warnings or errors in .out files. 
2. Using HyperView plot the strain and stress contour. 
Exercise Expected Results 
 
 
 
Von Mises Stress Contour (MPa) 
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Plastic Strain (mm/mm) 
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RD-3599: Gasket with HyperMesh 
This tutorial demonstrates how to simulate a rubber gasket in sequential loading, given the 
following load sequence: 
 Translation Transverse (10 mm) 
 Translation Longitudinal (5 mm) 
 Torsion (20 Degrees) 
 
Model Description 
 
 
 UNITS: Length (mm), Time (ms), Mass (kg), Force (kN) and Stress (GPa) 
 Simulation time: 
o Engine [0 – 1.501] in steps of 0.5 ms for each load case 
 The outer circumference area is fixed on all degrees of freedom (VX, VY, VZ) and the center 
node is fixed on X direction and the X and Y rotation (VX, WX, Wy) 
 The gasket dimensions are: Thickness= 100 mm, External Diameter = 200 mm and Internal 
Diameter = 50 mm. 
 Hyper-Elastic Material /MAT/LAW42 (Rubber) 
[Rho_I] Initial density = 6.0-6 Kg/mm3 
[nu] Poisson’s ratio = 0.495 
[mue1] ( 1) = 0.6 
[alfa1] ( 1) = 2 
(alfa2] ( 2) = -2 
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Exercise 
 
 
Step 1: Load the RADIOSS (Block) User Profile 
1. Launch HyperMesh Desktop. 
2. From the Preferences menu, select the User Profiles or click the icon in toolbar. 
3. Select RADIOSS (Block140) and click OK. 
Step 2: Load the gasket.hm file 
1. From the toolbar, click the Open Model icon to open the gasket.hm file you saved to your 
working directory from the radioss.zip file. Refer to Accessing the Model Files. 
2. Click Open. The model loads into the graphics area. 
Step 3: Define and assign material, property to Rubber 
1. In the Model browser, right-click and select Create > Material to create material. 
2. For Name, enter rubber. 
3. For Card Image, select M42_OGDEN and click Yes in the confirmation window. 
4. Input the values, as shown below: 
 
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5. In the Model browser, right-click and select Create > Property to create property. 
6. For Name, enter gasket. 
7. For Card Image, select P14_SOLID and click Yes to confirm. 
 
8. In the Model browser, expand the Component folder and select GASKET. Right-click and Assign 
(or use the Entity Editor) the newly created property and material. 
Step 4: Create a component for the rigid body at center of Gasket 
1. In the Model browser, right-click and select Create > Component. 
2. For Name, enter center and switch Card Image to None and click Yes to confirm. 
3. Select any color for easy visualization. 
 
Step 5: Create a rigid body at center of Gasket 
1. From the 1D page, select the rigids panel. 
2. For primary node, switch to calculate node. 
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3. For nodes 2-n, switch to multiple nodes. 
4. Click the nodes and select a node in the inner face. 
5. Click nodes and select by face. HyperMesh will select all nodes on the inner face. 
6. Click create. 
7. Click return to exit the panel. 
 
Step 6: Create gasket inner fixed boundary conditions 
1. From the Utility page, start the BCs Manager. 
2. For Name, enter Inner_BC, set Select type to Boundary Condition and set the GRNOD to 
Nodes. 
3. Select the master node of rigid body created in Step 5 and click proceed. 
4. Check the Tx translational and Rx, Ry rotational degrees of freedom. 
5. Click Create to create the inner fixed boundary condition. 
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Step 7: Create gasket inner Y displacement boundary conditions 
1. From the Utility page, start the BCs Manager. 
2. For Name, enter DISP_Y, set Select type to Imposed Displacement and set the GRNOD to 
Nodes. 
3. Select the master node of rigid body created in Step 5. 
4. Set Direction as Y. 
5. Click Create/Select curve to go to the XY curve editor. 
6. Click New and enter Name as DISP_Y. Click proceed. 
7. Enter the following values for X and Y: 
X = {0, 0.5, 1.0} 
Y = {0, 10, 10} 
8. Click Update and Close the XY curve editor GUI. 
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9. Click Create to create the boundary condition. 
Step 8: Create gasket inner Z displacement boundary conditions 
1. From the Utility page, start the BCs Manager. 
2. For Name, enter DISP_Z, set Select type to Imposed Displacement and set the GRNOD to 
Nodes. 
3. Select the master node of rigid body created in Step 5. 
4. Set Direction as Z. 
5. Click Create/Select curve to go to the XY curve editor. 
6. Click New and enter Name as DISP_Z. Click proceed. 
7. Enter the following vales for X and Y: 
X = {0, 0.5, 1, 1.5} 
Y = {0, 0, 5, 5} 
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8. Click Update and Close the XY curve editor GUI. 
 
9. Click Create to create the boundary condition. 
Step 9: Create gasket inner Z rotation boundary conditions 
1. From the Utility page, start the BCs Manager. 
2. For Name, enter ROT20DEG_Z, set Select type to Imposed Displacement and set the GRNOD 
to Nodes. 
3. Select the master node of rigid body created in Step 5. 
4. Set Direction as ZZ. 
5. Click Create/Select curve to go to the XY curve editor. 
6. Click New and enter Name as ROT20DEG_Z. Click proceed. 
7. Enter the following vales for X and Y: 
X = {0, 1, 1.5, 2} 
Y = {0, 0, 0.349, 0.349} 
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8. Click Update and Close the XY curve editor GUI. 
 
9. Click Create to create the boundary condition. 
Step 10: Create gasket outer boundary conditions 
1. From the Utility page, start the BCs Manager. 
2. For Name, enter OUTER_BC, set Select type to Boundary Condition and set the GRNOD to 
Nodes. 
3. Click Nodes and select a node on the outer surface. 
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4. Click Nodes on the panel and then select by face to select all nodes on the outer surface. 
5. Check all the translational and rotational degrees of freedom. 
6. Click Create to create the outer fixed boundary condition. 
 
Step 11: Create output request and control cards 
1. Launch the HyperMesh Solver browser from View > Browsers > HyperMesh > Solver. 
2. Right-click in the Solver browser general area to create the cards shown below with the given 
values for each parameter: 
Keyword Type Keyword Parameter Parameter Value 
CONTROL CARDS TITLE Status [Checked] 
CONTROL CARDS TITLE TITLE GASKET 
CONTROL CARDS MEMORY Status [Checked] 
CONTROL CARDS MEMORY NMOTS 40000 Not needed 
CONTROL CARDS SPMD Status [Checked] 
CONTROL CARDS IOFLAG Status [Checked] 
CONTROL CARDS ANALY Status [Checked] 
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Keyword Type Keyword Parameter Parameter Value 
ALE-CFD-SPH ALE_CFD_SPH_CARD Status [Checked] 
ALE-CFD-SPH ALE_CFD_SPH_CARD ALE_Grid_Velocity [Checked] 
ALE-CFD-SPH ALE_CFD_SPH_CARD GridVel_Gamma 100.00 
ENGINE KEYWORDS RUN Status [Checked] 
ENGINE KEYWORDS RUN RunName GASKET 
ENGINE KEYWORDS RUN Tstop 1.51 
ENGINE KEYWORDS PARITH Status [Checked] 
ENGINE KEYWORDS PARITH Keyword2 ON 
ENGINE KEYWORDS PRINT Status [Checked] 
ENGINE KEYWORDS PRINT N_Print -1000 
ENGINE KEYWORDS ANIM/ELEM Status [Checked] 
ENGINE KEYWORDS ANIM/ELEM VONM [Checked] 
ENGINE KEYWORDS ANIM/ELEM DENS [Checked] 
ENGINE KEYWORDS ANIM/ELEM PRES [Checked] 
ENGINE KEYWORDS ANIM/VECT Status [Checked] 
ENGINE KEYWORDS ANIM/VECT CONT [Checked] 
ENGINE KEYWORDS ANIM/DT Status [Checked] 
ENGINE KEYWORDS ANIM/DT Tstart 0 
ENGINE KEYWORDS ANIM/DT Tfreq 0.05 
ENGINE KEYWORDS DT Status [Checked] 
ENGINE KEYWORDS DT Tscale 0.0 
ENGINE KEYWORDS DT Tmin 0.0 
ENGINE KEYWORDS TFILE Time frequency 1.5e-3 
Step 12: Export the model 
1. Click File > Export or click the Export icon . 
2. For File:, navigate to the destination directory where you want to export to. 
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3. For name, enter GASKET and click Save. 
4. Click the downward-pointing arrows next to Export options to expand the panel. 
5. Click Merge starter and engine file to export solver deck as one file (or export separately). 
6. Click on Export to export solver deck. 
Step 13: Open RADIOSS Manager from windows Start menu 
1. Go to Start > Programs > Altair HyperWorks 2017 > RADIOSS. 
2. For Input file, browse to the exercisefolder and select the file GASKET_0000.rad. 
 
Step 14: Review the listing files for this run and verify on the results 
1. See if there are any warnings or errors in .out files. 
2. Using HyperView plot the displacement and strain contour and vectors. 
 
Exercise Expected Results 
 
 
 
Displacement Contour for the 3 load steps (mm) 
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Von Mises Stress Contour at the end of the simulation 
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Examples 
This manual illustrates examples solved using the RADIOSS software with regard to common 
problem types. 
The main purpose of this manual is: 
 First, is to illustrate examples for validation using uncommon models for carrying out various 
RADIOSS functionalities. Whenever possible, the results provided by RADIOSS are compared 
with experimental data or analytical solutions. Furthermore, when the computation time is 
significant, different types of formulations are compared in order to provide users with an 
overall idea of the cost for a given option or formulation. 
 Second, as a guide for new RADIOSS users or for users interested in a type of problem with 
which they are not familiar. The data is provided to enable a detailed understanding of the 
options used for modeling. The reader can load data files or process the results obtained at a 
later stage. The techniques for modeling can be applied to similar problems. 
 Third, to explain about the additional functions included in the RADIOSS data files, thus 
providing helpful options when using the RADIOSS data input manuals. 
 
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List of Examples 
 
 
1 – Twisted Beam 
Torsion - bending coupling 
Sensitivity study on mesh and 
element formulations. 
 
2 – Snap-through Roof 
Snap-through problem solved 
by explicit and implicit solvers. 
Results are compared with 
experiments. 
 
3 – S-beam Crash 
Sensitivity study on element 
formulations, plasticity 
treatment and boundary 
conditions for impact. 
 
4 – Airbag 
Airbag deployment using 
monitored volumes with 
communications. 
Perfect gas modeling. 
 
5 – Beam Frame 
Transient dynamic analysis 
using beam elements. 
 
6 – Fuel Tank 
Fluid-structure coupling and 
fluid flow are studied using ALE 
formulation. 
Two analyses are performed: 
sloshing and fuel tank 
overturning. 
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7 – Pendulums 
Momentum transmission, 
contact modeling, bi- and tri-
dimensional analysis. 
 
8 – Hopkinson Bar 
Study of the stress wave 
propagation and the strain rate 
effect on the Hopkinson bar. 
 
9 – Billiards (Pool) 
Impact between balls, 
trajectory study and treatment 
with several interfaces 
(Penalty/Lagrangian method). 
 
10 – Bending 
Pure bending test. 
Sensitivity study on mesh and 
element formulations. 
3- and 4-nodes shell. 
 
11 – Tensile Test (Material 
Characterization) 
Correlations between 
simulations and experimental 
results. Treatment of the 
necking point and the failure. 
 
12 – Jumping Bicycle 
A sequence of events managed 
using "sensors". 
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13 – Shock Tube 
Analysis with SPH, Lagrangian 
and Eulerian formulations. 
Correlation with theory. 
Perfect gas modeling. 
 
14 – Truck with Flexible 
Body 
Creating an overall flexible 
body. 
Quasi-static treatment 
(gravity). 
Eigen analysis (flexible body 
inputs) 
Dynamic analysis (bump). 
 
15 – Gears 
Contact modeling for quadratic 
surface with interfaces 16 and 
17. 
 
16 – Dummy Positioning 
Quasi-static analysis by explicit 
solver with different 
convergence options. 
Static analysis by implicit solver 
(linear and nonlinear problem). 
 
17 – Box Beam 
Crash test. 
Sensitivity study on mesh and 
element formulations. 
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18 – Square Plate 
Torsion and tension-
compression tests. 
Sensitivity study on mesh and 
element formulations. 
 
19 – Wave Propagation 
Bi-dimensional wave 
propagation. 
Lagrangian and ALE 
formulations. 
Infinite domain modeling. 
 
20 – Cube 
Demonstrative problem. 
Contact modeling. 
Co-rotational formulation 
elements. 
 
21 – Cam 
Contact modeling. 
Linear and quadratic surface. 
Comparison of fine and coarse 
meshes. 
 
22 – Ditching 
Fluid simulation using the 
Smooth Hydrodynamic Particles 
formulation. 
Comparison with experimental 
data. 
 
23 – Brake 
Frictional contact modeling. 
Lagrangian formulation. 
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24 – Laminating 
Study of the number of 
elements with regard to 
thickness, the large/small 
strain formulation, plastic strain 
formulation and temperature 
dependency. 
 
25 – Spring-back 
Explicit stamping simulation 
followed by an implicit/explicit 
spring-back simulation. Final 
shape of the sheet metal is 
compared with experiments. 
 
26 – Ruptured Plate 
Perforation of a thick plate by a 
rigid sphere. Different failure 
models integrated in material 
law (2 and 27) or independent 
(/FAIL options) are used. 
 
27 – Football (Soccer) Shots 
Simulations of football (soccer) 
shooting impacts on a round or 
a square bar. The airbag 
modeling is used. 
 
37 – Analytical Beam 
Illustrates how to prepare a 
RADIOSS deck for linear 
analysis, and demonstrates a 
high quality of RADIOSS finite 
elements to resolve linear and 
nonlinear problems. 
 
39 - Biomedical Valve 
A Fluid-Structure-Interaction 
(FSI) problem is studied. 
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42 - Rubber Ring 
Crush and Slide 
 
43 - Perfect Gas 
Polynomial EOS is used to 
model Perfect Gas. 
 
44 - Blow Molding with AMS 
Blow molding with Advanced 
Mass Scaling (AMS). 
 
45 - Multi-Domain 
Separate the whole model into 
master domain and sub-
domain. 
 
46 - TNT Cylinder Expansion 
Test 
An experimental test used to 
characterize the adiabatic 
expansion of detonation 
products. 
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47 - Concrete Validation 
Three kinds of tests are 
performed in order to evaluate 
the simulation/experiment 
correlation. 
 
48 - Solid Spotweld 
Solid spotweld connects two 
metal sheets with tied contact. 
 
49 - Bird Strike on 
Windshield 
Introduce how to simulate a 
bird hitting a windshield. 
 
50 - INIVOL and Fluid 
Structure Interaction (Drop 
Container) 
Introduces /INIVOL for initial 
volume fractions of different 
materials in multi-material ALE 
elements, /SURF/PLANE for 
infinite plane, and fluid 
structure interaction (FSI) with 
a Lagrangian container. 
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51 - Optimization in 
RADIOSS for B-Pillar 
The optimization objective is to 
minimize the mass of the B-
Pillar by changing the shell 
thickness. 
 
52 - Creep and Stress 
Relaxation 
How to use typical visco-elastic 
material to simulate creep and 
stress relaxation tests. 
 
53 - Thermal Analysis 
A heat source moved on one 
plate. Heat exchanged between 
heat source and plate through 
contact also between plate and 
atmosphere (water) through 
convective flux. 
 
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Example 1 - Twisted Beam 
 
Summary 
 
 
This example deals with a clamped beam subjected to a coupled torsion-bending loading. This 
simple test being particularlysevere for shell elements, a sensitivity study is performed on the 
mesh and element formulation. An analytical solution validates the accuracy of results. The problem 
under analysis consists of a concentrated load being applied to the extremity of the beam with the 
static approach requiring a convergence method to enable fast convergence towards equilibrium. 
The dynamic relaxation option allows for an efficient quasi-static response to be obtained. 
The results are compared using two separate views: 
 Shell element formulations (BATOZ, QEPH, DKT18 and BT hourglass type 4). 
 Influence of the mesh (Triangular and quadrilateral meshes are compared using three 
different element densities: 4x24, 2x12 and 1x3). 
Several results can be extracted: 
 X-displacement of the loaded point 
 Y-displacement of the loaded point 
 Z-displacement of the loaded point 
 Error on energy 
 CPU time 
Comparisons are made between theoretical displacements and those by simulations. 
Results show that QEPH and BATOZ element formulations provide the most accurate results and the 
more the mesh is fine, the more accurate the results will be. To pass this test, a good curvature 
representation of element formulation is needed; the BT hourglass type 4 formulation does not 
satisfy this condition. QEPH offers a good ratio in terms of precision-cost, and is useful for quasi-
static analysis. DKT18 is a costly element formulation. 
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Title 
Twisted beam 
 
Number 
1.1 
Brief Description 
Bending test on a twisted beam modeled with triangular and quadrilateral meshes and different 
element formulations (QEPH, BT hourglass type 4, BATOZ, DKT). 
Keywords 
 4-node shell (Q4) and 3-node shell (T3) 
 QEPH, BT (Hourglass type 4), BATOZ and DKT18 
 Density mesh, elasticity, and dynamic relaxation 
 Linear problem 
RADIOSS Options 
 Concentrated load (/CLOAD) 
 Dynamic relaxation (/DYREL) 
Compared to / Validation Method 
 Analytical solution 
Input File 
QEPH: <install_directory>/demos/hwsolvers/radioss/01_Twisted_Beam/QEPH/TWISBEAM* 
BATOZ: <install_directory>/demos/hwsolvers/radioss/01_Twisted_Beam/BATOZ/TWISBEAM* 
BT-TYPE4: <install_directory>/demos/hwsolvers/radioss/01_Twisted_Beam/BT-
type4/TWISBEAM* 
DKT18: <install_directory>/demos/hwsolvers/radioss/01_Twisted_Beam/DKT18/TWISBEAM* 
Technical / Theoretical Level 
Medium 
Overview 
 
 
Aim of the Problem 
The purpose of this example is to compare element formulations concerning mesh density with 
regard to a coupled torsion-bending problem. 
Physical Problem Description 
Units: In, s, lbs-s2/in 
A twisted beam is clamped at one end, and subjected to a concentrated load at the other end. 
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The material used follows a linear elastic law (/MAT/LAW1) and has the following geometrical 
characteristics with no specific measurement unit: 
Initial density: 7.34x10-4 
Young’s modulus: 2.9x107 [MPA] 
Poisson ratio: 0.22 
Thickness: 0.32 
Length: 12 
Width: 1.1 
Load case: 
Fx = 0 
Fy = 1.0 
Fz = 0 
 
Fig 1: Initial mesh (4x24). 
This simple test is particularly severe for shell element behaviors, due to the torsion-bending 
coupling. Users appreciate the qualities/restrictions of the shell element formulations in RADIOSS. 
The following points are: 
 Displacements are very low. Thus, you are faced with a linear problem. 
 Another load case, using Fy = 0 and Fz = 1, is considered, but does not give concern to 
additional conclusions. 
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Analysis, Assumptions and Modeling Description 
 
 
Modeling Methodology 
The beam is modeled with 4-node shell and 3-node shell meshes. 
The following are tested for each model: 
 Four shell formulations: 
- QEPH formulation (4-node shell element, Ishell = 24) 
- BT (Hourglass type 4) formulation (4-node shell element, Ishell = 4) 
- QBATOZ formulation (4-node shell element, Ishell = 12) 
- DKT18 formulation (3-node shell element, Ish3n = 30) 
 Three mesh densities in each shell formulation: 
- Mesh A: 4 x 24 elements 
- Mesh B: 2 x 12 elements 
- Mesh C: 1 x 3 elements 
4-node Shell Mesh 3-node Shell Mesh 
 
 
RADIOSS Options Used 
One concentrated load is applied at the extremity, on central node M (for mesh A and mesh B), two 
concentrated loads must be applied to the corner points of the beam end (for mesh C). 
A static solution provides the steady state part of the transient response. In this example, dynamic 
relaxation is used to obtain a static result. Static loading is considered a dynamic resolution 
method. Using /DYREL in the *_0002.rad file, the dynamic loading is damped by introducing a 
diagonal damping matrix. 
Relaxation factor = 1; period to be damped = 0.0025 
The displacement of node M is stabilized at the static response: t = 0.035. 
For further details, refer to the RADIOSS Theory Manual. 
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Simulation Results and Conclusions 
 
 
Curves and Animations 
The displacement components regarding X, Y and Z of node M are compared to the beam theory in 
order to understand the performance of the various elements when several mesh densities are 
used. 
Reference results [Batoz & Dhatt, "Structural Modeling Finite Elements", Vol. 3, Hermès, Paris, 
1992]: 
X-displacement: UM = 0 
Y-displacement: VM = 0.00175 
Z-displacement: WM = -0.00179 
The chart below shows the displacement oscillations of point M until reaching stabilization in the 
direction of the static solution. 
 
Fig 2: Time history plots of point M displacements (Mesh A/QEPH) 
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 Energy margin error at t = 0.05: 
 QEPH BT (type 4) BATOZ DKT18 
Energy 
margin error 
0.1% 
99.9% 
(diverge) 
0% 0% 
 
 CPU (normalized): 
 QEPH BT (type 4) BATOZ DKT18 
CPU 1 diverge 1.1042 1.1430 
 
 Nodal displacements of node M: 
 
 
 Ratio (Displacement by simulation/ Displacement by theory): 
 
Conclusion 
 
 
 QBAT and QEPH provide good results (precision). 
 Good results provided by DKT18 when the mesh is fine, though no better than QBAT and 
QEPH. 
 BT (Hourglass type 4) does not pass this test (due to the flat facet approach). 
 QEPH: the best element formulation for quasi-static analysis. Very good precision-cost ratio. 
 QBAT: good curvature representation. For quasi-static analysis, the cost is 4% higher 
compared to using the QEPH formulation. 
 DKT18 represents the highest cost for this test. 
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Example 2 - Snap-thru Roof 
 
Summary 
 
 
A snap-through problem is studied on a shallow cylindrical roof upon which an imposed velocity is 
applied at its mid-point. The characteristic curve, caused by the limit load and achieved by 
simulation is compared to a reference. This example is considered a static problem. 
Only one-quarter of the structure is taken into consideration and adequate boundary conditions are 
applied on the model sides. 
The problem is solved using two different approaches: 
 An analysis by an explicit solver 
 An analysis by an implicit solver 
The implicit strategy uses the arc-length method with a time step limitation. The RADIOSS implicit 
options are defined in the modeling description. 
The simulations using explicit and implicit methods provide accurate results with a good evaluation 
of the limit load experimentally observed. A time step control with a low value is required in order 
to describe the nonlinear path of the load displacement curve. Both computationsconverge toward 
a single solution. 
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2.1 - Snap Roof: Explicit 
 
Title 
Snap Roof - Explicit 
 
Number 
2.1 
Brief Description 
An imposed velocity is applied onto a shallow cylindrical roof at its midpoint. The analysis uses an 
explicit approach. 
Keywords 
 Explicit solver 
 T3 Shell 
 Elasticity and quasi-static analysis 
 Stability, snap-through problem, and limit load 
RADIOSS Options 
 Boundary conditions (/BCS) 
 Imposed velocity (/IMPVEL) 
 Rigid body (/RBODY) 
Compared to / Validation Method 
 Experimental results 
Input File 
Explicit solver: <install_directory>/demos/hwsolvers/radioss/02_Snap-
through/Explicit_solver/SNAP_EXP* 
Technical / Theoretical Level 
Beginner 
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Overview 
 
 
Aim of the Problem 
The purpose of this example is to study a snap-thru problem with a single instability. Thus, a 
structure that will bend when under a load is used. The results are compared to the references 
contained in: Finite Element Instability Analysis of Free Formed Shells. Report 77−2, 1977, 
Norwegian Institute of Technology, Trondheim, HORRIGMOE G. 
This static analysis is performed with an explicit approach. 
Physical Problem Description 
A shallow cylindrical roof, pinned along its straight edges upon which an imposed velocity is applied 
at its mid-point. 
Units: mm, ms, g, N, MPa 
Geometrical data are provided in Fig 1, with the following dimensions: 
 l = 254 mm 
 R = 2540 mm 
 Shell thickness: t = 12.7 mm 
 = 0.1 rad 
 
Fig 1: Geometrical data of the problem 
The material used follows a linear elastic law and has the following characteristics: 
 Initial density: 7.85x10-3 g/mm3 
 Young modulus: 3102.75 MPa 
 Poisson ratio: 0.3 
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Analysis, Assumptions and Modeling Description 
 
 
Modeling Methodology 
The structure is considered perfect, having no defects. To take account of the symmetries, only a 
quarter of the shell is modeled (surface ABCD). 
A regular mesh with a total of 72 3-node shells (Fig 2) 
 
Fig 2: T3 mesh 
The shells have the following properties: 
 Thickness 12.7 mm 
 BT Elasto-plastic Hourglass formulation (Ishell = 3). 
RADIOSS Options Used 
Node time histories do not indicate the pressure output. In order to obtain such output at point C, a 
rigid body must be created at this point. Point C has a constant imposed velocity of -0.01 ms-1 in 
the Z direction. Its displacement is linked proportionally to time. 
Boundary conditions are: 
 Edge BC is fixed in an X translation, and in Y and Z rotations (symmetry conditions). 
 Edge CD is fixed in a Y translation, and in X and Z rotations (Idem). 
 Edge DA is fixed in X, Y, Z translations, and in X and Z rotations. 
 Point C is fixed in X, Y translations, and in X, Y, Z rotations. 
 
Fig 3: Boundary conditions 
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Simulation Results and Conclusions 
 
 
Curves and Animations 
Only a quarter of the total load is applied due to the symmetry. Therefore, force Fz of the rigid 
body, as indicated in the Time History, must be multiplied by 4 in order to obtain force, P. 
Figure 4 represents a characteristic load displacement curve for a snap-through. This diagram plots 
the reaction at point C of the shell as a function of its vertical displacement. 
 
Fig 4: Load P versus displacement of point C: snap-thru instability. 
The displacement of point C is indicated in its absolute value. The curve illustrates the characteristic 
behavior of the instability of a snap-thru. Beyond the limit load, an infinite increase in load Fz will 
cause a considerable increase in displacement q due to the collapsing of the shell. 
The first extreme defines the limit load =2208.5 N (displacement of point C = 10.5 mm). 
The increase in the curve slope after the snap-thru, shows that the deformed configuration becomes 
more rigid. 
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Fig 5: Comparison between a reference curve and a curve obtained using RADIOSS 
The difference between the two curves is approximately 10% for reduced displacements (up to 5 
mm) and slightly more (15%) for the higher nonlinear part of the curve (between 5 and 20 mm). 
For displacements exceeding 20 mm, the curves are shown much closer together. 
The accuracy of the RADIOSS results in comparison to those obtained from the reference is ideal for 
this explicit approach. 
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Deformed Mesh (profile view) – Displacement Norm 
 
 
Initial configuration 
 
 
Start of snap-thru 
 
 
Large motion phase 
 
 
Stable configuration 
 
 
Loading with a new structural rigidity 
 
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2.2 - Snap Roof: Implicit 
 
Title 
Snap Roof - Implicit 
 
Number 
2.2 
Brief Description 
A shallow cylindrical roof upon which an imposed velocity is applied at its mid-point. Analysis uses 
an implicit approach. 
Keywords 
 Implicit solver, time step control by arc-length method 
 Static nonlinear analysis 
 Stability, snap-thru, and limit load 
 T3 Shell 
RADIOSS Options 
 Boundary conditions (/BCS) 
 Implicit options (/IMPL) 
 Imposed velocity (/IMPVEL) 
 Rigid body (/RBODY) 
Compared to / Validation Method 
 Experimental results 
Input File 
Implicit solver: <install_directory>/demos/hwsolvers/radioss/02_Snap-thru/ 
Implicit_solver/SNAP_IMP* 
Technical / Theoretical Level 
Advanced 
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Overview 
 
 
Aim of the Problem 
The purpose of this example is to study a snap-thru problem with a single instability. Thus, a 
structure that will bend when under a load will be used. The results are compared to a reference 
solution [1]. This analysis is performed using an implicit approach. An implicit strategy using an arc-
length method is illustrated. 
Physical Problem Description 
A shallow cylindrical roof, pinned along its straight edges, upon which an imposed velocity is applied 
at its mid-point. 
Units: mm, ms, g, N, MPa 
Geometrical data are indicated in Fig 6, with the following dimensions: 
 l = 254 mm 
 R = 2540 mm 
 Shell thickness: t = 12.7 mm 
 = 0.1 rad 
 
Fig 6: Geometrical data of the problem 
The material used follows a linear elastic law and has the following characteristics: 
 Initial density: 7.85x10-3 g/mm3 
 Young modulus: 3102.75 MPa 
 Poisson ratio: 0.3 
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Analysis, Assumptions and Modeling Description 
 
 
Modeling Methodology 
The modeling problem described in the explicit study remains unchanged. 
The implicit computation requires specific implicit parameters that must be defined in the Engine file 
*_001.rad using the options beginning with /IMPL. 
 
Fig 7: Description of the problem (one quarter of the shell is modeled) 
The imposed velocity is considered using the implicit method. Thus, the constant input curve is 
converted into an imposed displacement according to the computation time. 
 
Fig 8: Imposed velocity curve 
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RADIOSS Options Used 
The limit point causes major non-linearities. Therefore, a static nonlinear analysis is performed 
using the arc-length displacement strategy. The time step is determinedby a displacement norm 
control. In order to exceed the limit point characterized by a null tangent on the load displacement 
curve and to describe the increasing and decreasing parts of the nonlinear path, a small time step is 
required, which is ensured by setting a maximum value. 
The nonlinear implicit parameters used are: 
Implicit type: Static nonlinear 
Nonlinear solver: Modified Newton 
Tolerance: 2x10-4 
Update of stiffness matrix: 3 iterations maximum 
Time step control method: Arc-length 
Initial time step: 10 ms 
Minimum time step: 0.5 ms 
Maximum time step: 10 ms 
Desired convergence iteration number: 6 
Maximum convergence iteration number: 20 
Decreasing time step factor: 0.8 
Maximum increasing time step scale factor: 1.05 
Arc-length: Automatic computation 
Spring-back option: no 
A solver method is required to resolve Ax=b in each iteration of a nonlinear cycle. It is defined in 
/IMPL/SOLVER. The linear implicit options used are: 
Linear solver: Direct solver MUMPS 
Precondition methods: Factored approximate Inverse 
Maximum iterations number: System dimension (NDOF) 
Stop criteria: Relative residual in force 
Tolerance for stop criteria: Machine precision 
The input implicit options set in *_001.rad are: 
/IMPL/PRINT/NONL/-1 Printout frequency for nonlinear iteration 
/IMPL/SOLVER/2 
5 0 0 0.0 
Solver method (solve Ax=b) 
/IMPL/NONLIN 
3 1 0.20e-3 
Static nonlinear computation 
/IMPL/DTINI 
10 
Initial time step determines the initial loading increment 
/IMPL/DT/STOP 
0.5 10 
Min Max values for time step 
/IMPL/DT/2 
6.0 20 0.8 1.05 
Time step control method 2 - Arc-length+Line-search will be used 
with this method to accelerate and control convergence 
Refer to RADIOSS Starter Input for more details about implicit options. 
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Simulation Results and Conclusions 
 
 
Curves and Animations 
Only a quarter of the total load is applied due to the symmetry. Thus, force Fz of the rigid body as 
indicated in the Time History must be multiplied by 4 in order to obtain force, P. 
Figure 9 represents the characteristic load displacement curve for a snap-thru. This diagram plots 
the reaction at point C of the shell as the function of its vertical displacement. The implicit results 
are compared with the experimental data. 
 
Fig 9: Load P versus displacement of point C. 
For a time step equal to or less than 10 ms (maximum value set in the implicit /IMPL/DT/STOP 
option), agreement with RADIOSS is achieved, with good results obtained using the reference. 
Accuracy is improved by decreasing the maximum time step, even though the CPU time is 
increased. 
 
Fig 10: Deformed configurations during the snap-thru. 
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Comparison between Implicit and Explicit Results 
The load displacement curves achieved through implicit computations (time step limit set to 10 ms) 
and explicit computations are very close. A maximum time step of 100 ms does not allow the 
nonlinear path of the load displacement curve to be described accurately. However, the final static 
solution is correct. 
 
Fig 11: Load displacement curve obtained by implicit and explicit solvers. 
Comparison of the computation time between the explicit and implicit (maximum time step set to 
10 ms) approaches is shown in the table below: 
 Implicit solver Explicit solver 
Normalized CPU 1 2.45 
Cycles (normalized) 1 237 
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In comparison with the implicit computation, which uses a maximum time step of 10 ms, the saved 
CPU time using a maximum time step fixed at 100 ms, approximately corresponds to factor 4. 
Reference 
[1] Finite Element Instability Analysis of Free Formed Shells. Report 77−2, 1977, Norwegian 
Institute of Technology, Trondheim, HORRIGMOE G. 
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Example 3 - S-beam Crash 
 
Summary 
 
 
A sensitive study is performed on a crushed S-beam. The modeling includes a material law using 
the elasto-plastic model of Johnson-Cook and a self-impacting interface based on the Penalty 
method in order to model the buckling of the beam. An initial velocity is applied on the left section 
via a kinematic condition: either a rigid body or a rigid link. The impacting condition is sliding and is 
secured by specific boundary conditions in the right section. Half of the structure is modeled. 
The results are compared according to three different views: 
 Shell element formulations (BATOZ, QEPH and BT hourglass type 3) 
 Plasticity options (global and progressive plasticity) 
 Influence of the initial velocity (5 and 10 ms-1) 
Several criteria are used to compare the results: 
 Deformation configuration 
 Crushing force versus displacement (via momentum integration) 
 Energy assessment 
 Displacement of the left section 
 Hourglass energy 
 Kinetic energy 
 Internal energy 
 Maximum force 
 Maximum plastic strain 
BATOZ and QEPH element formulations provide accurate results. The BT hourglass type 3 
formulation is a low-cost method and the QEPH formulation provides a good precision/cost ratio 
(the cost is three times lower than the BATOZ formulation). BATOZ and QEPH are element 
formulations which do not have hourglass energy. 
The results show an over-estimation of the plastic strain in the case of the global plasticity use. 
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Title 
S-Beam 
 
 
Number 
3.1 
Brief Description 
An S-beam is crushed against a rigid wall with initial velocity. 
Keywords 
 Shell, type 3 Q4 Hourglass, QEPH, and BATOZ 
 Type 7 interface, self-impacting, plasticity, and /MAT/LAW2 
 MODIF files 
RADIOSS Options 
 Initial velocities (/INIVEL) 
 Rigid body (/RBODY) 
 Rigid link (/RLINK) 
Input File 
QEPH: <install_directory>/demos/hwsolvers/radioss/03_S-Beam/QEPH/ 
Global_plasticity/QEPH* 
BATOZ: <install_directory>/demos/hwsolvers/radioss/03_S-Beam/BATOZ/ 
Global_plasticity/BATOZ* 
BT_type3_NiP0: <install_directory>/demos/hwsolvers/radioss/03_S-Beam/BT-type3/ 
Global_plasticity/Q4_NIP0* 
BT_type3_NiP5: <install_directory>/demos/hwsolvers/radioss/03_S-Beam/BT-type3/ 
NiP5/Q4_NIP5* 
Technical / Theoretical Level 
Advanced 
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Overview 
 
 
Aim of the Problem 
The purpose of this example is to study the behavior of a crashed S-beam using various shell 
formulations and a number of different integration points. This test also compares the initial velocity 
influence on results. A MODIF file is used to introduce a self-impacting interface. 
Physical Problem Description 
An S–beam is crushed at an initial rate of 5 ms-1 against a rigid wall. The section is an empty 
square-shaped tube (each side measuring 80 mm). The thickness is 1.5 mm. The tube is made of 
steel, and plasticity is taken into account, but not failure. Using symmetry, half of the cross-section 
is modeled. 
 
Fig 1: Problem description and beam cross-section. 
The following system is used: mm, ms, g, N, MPa 
The material used follows an isotropic elasto-plastic Johnson-Cook law. 
Material properties: 
 Young’s modulus: 199355 MPa 
 Poisson’s ratio: 0.3 
 Density: 7.9x10-3 g/mm3 
 Yield stress: 185.4 MPa 
 Hardening parameter: 540 MPa 
 Hardening exponent: 0.32 
 Maximum stress: 336.6 MPa 
All other properties are set to the default values. 
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Analysis, Assumptions and Modeling Description 
 
 
Modeling Methodology 
Themesh is a regular shell mesh. Each shell measures approximately 10 mm x 10 mm. 
A sensitive study is performed on: 
 Shell element formulations: BATOZ, QEPH and Belytschko hourglass type 3 
 Plasticity options: global and progressive plasticity model 
 Influence of the initial velocity: 5 and 10 ms-1 
 
Fig 2: Structure’s overall mesh 
The rigid wall is modeled with boundary conditions on the right section of the beam (X, Z 
translations and all rotations fixed). 
The left section undergoes the following conditions: 
 Fixed in the Z direction. 
 Initial velocity of 5 m/s in the X direction. 
 All nodes are rigidly connected in X, Y and Z directions. 
 A 500 Kg mass is added on the left end. 
Block format input specifications: 
 Hierarchy organization: there is only one subset made up of three parts, one for each side of 
the beam, and one for the top. The materials and properties are identical for each part. 
 Node groups: there are three node groups, one for each end of the beam, and one for the 
symmetry plane. The boundary conditions are set on the left end. 
 TH selection: DX is saved for node 1 (the node used to display displacement at the left end). 
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RADIOSS Options Used 
Taking account of symmetry, half of the structure is modeled. The symmetry plane covers the y 
axis = 0 mm. Boundary conditions are also set at the right end to simulate a rigid wall (slide). 
Two equivalent possibilities are available for generating kinematic conditions attached to the left 
extremity of the beam. The first consists of creating a rigid body to connect all of the left section 
nodes to the gravity center of the beam cross-section, with a mass being introduced on a master 
node. The second type of modeling retained uses the rigid link option, which rigidly connects the left 
section nodes in the X, Y and Z directions. A 500 kg mass is added to the master node. 
 
Both models provide identical results; the rigid link will be used for this example. 
 An initial velocity of 5 ms-1 is used for the master node of the rigid link or for the rigid body. 
 MODIF file: 
A MODIF file enables to add option(s) during a run. The MODIF files carry the name 
ROOTNAMErun*.rad. Where, run# is the RADIOSS run number four digits from 0000 to 9999 
and run# is the name of the last Restart file + 1. 
For example, to run a MODIF file after the first run (restart file ROOTNAME_0001.rad), the run 
number for the MODIF file must be 2: ROOTNAME_0002.rad. MODIF files use the same inout 
format as the RADIOSS deck. Put all the input decks in one folder and with Irun=2 RADIOSS 
will automatically recognize the MODIF file. 
 
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After 20 ms, a self-impacting interface is required to deal with the buckling of the beam. This is 
added using a MODIF file where the interface is defined and saved for the TH. This type of interface 
corresponds to 7; all values are set to "default". To define the master side, a surface is defined 
using three parts of the model (/SURF/PART). The safest and easiest method for defining the slave 
side of a self-impacting interface consists of defining a node group with the master surface 
(/GRNOD/SURF). 
The MODIF file is ROOTNAME_0002.rad. 
The next Engine file is ROOTNAME_0003.rad (final time = 30 ms). 
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Fig 3: Contact force at the start of self-impacting. 
The MODIF file options used in Engine file ROOTNAME_0002.rad are: 
 
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Simulation Results and Conclusions 
 
 
Curves and Animations 
 
Fig 4: Deformed mesh for Belytschko hourglass type 3 formulation (V=5 m.s-1) 
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The crushing force is obtained by time derivation of the X-momentum. The maximum displacement 
over a 20 ms long computation corresponds to 96.4 mm. 
 
Fig 5: Crushing force (X-direction) versus displacement for different element formulations (V=5 m.s-1) 
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Fig 6: Energy assessment for Belytschko hourglass type 3 (V=5 m.s-1). 
The structure does not absorb a lot of energy and that you should check the hourglass energy, 
which may be relatively high compared with the total energy. 
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The following table shows the results obtained using different element formulations and plasticity 
options: 
 
 
Global plastification (NiP = 0) NiP = 5 
BATOZ QEPH 
Q4 Hourglass 
type 3 
Q4 Hourglass 
type 3 
Initial energy (mJ) 6.25012x106 6.25012x106 6.25012x106 6.25012x106 
Kinetic energy (mJ) 
t = 30 ms 
5.499x106 
(0.877) 
5.47964x106 
(0.875) 
5.55602x106 
(0.889) 
5.55641x106 
(0.888) 
Internal energy (mJ) 
t = 30 ms 
750374 
(0.123) 
770384 
(0.125) 
684100 
(0.109) 
691255 
(0.110) 
Hourglass energy (mJ) 
t = 30 ms 
0 0 28385 
(0.0016) 
33341.6 
(0.002) 
Displacement (mm) 
t = 30 ms 
144.0 144.6 144.6 144.7 
CPU 
(Normalized) 
1.082 0.99 1 0.988 
Error on energy (%) 
t = 30 ms 
0% 0% -0.1% -0.1% 
Maximum force (N) 42459.4 42688.5 35949.4 35387.2 
Maximum plastic strain 0.462 0.448 0.414 0.323 
Initial velocity = 5 ms-1 (Values in brackets are the energy percentages compared with the initial energy) 
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Plastic Strain - Time = 10.00 ms 
Global plastification 
 
Progressive plastification (Nip = 5) 
 
Plastic Strain - Time = 30.00 ms 
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Plastic Strain - Time = 10.00 ms 
Global plastification 
 
Progressive plastification (Nip = 5) 
 
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Initial Velocity Influence 
The following table indicates the influence of the crushing velocity (5 ms-1 and 10 ms-1). 
 
 Initial Velocity = 5 ms-1 Initial Velocity = 10 ms-1 
Initial energy (mJ) 6.25012x106 2.5 x107 
Kinetic energy (mJ) 
 
X – displacement = 70 mm: 
X – displacement = 140 mm: 
5.79897x106 (0.928) 
5.57192x106 (0.891) 
2.44581x107 (0.978) 
2.41546 x107 (0.966) 
Internal energy (mJ) 
 
X – displacement = 70 mm: 
X – displacement = 140 mm: 
444848 (0.0711) 
666704 (0.107) 
538142 (0.0215) 
840622 (0.0336) 
Hourglass energy (mJ) 
 
X – displacement = 70 mm: 
X – displacement = 140 mm: 
4879.87 (0.0009) 
9530.27 (0.002) 
5969.83 (0.0005) 
12702.4 (0.0004) 
Maximum force (N) 35949.4 41704.3 
Error on energy (%) -1.09% -1.11% 
(Values in brackets refer to the energy percentages compared with the initial energy) 
BT hourglass type 3 formulation is used in this section. 
The amount of internal energy stored in the beam during a crash is relatively higher when the initial 
velocity is set to 10 ms-1, instead of 5 ms-1. The hourglass energy is quite low with either initial 
velocity. 
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Fig 7: Crushing force versus displacement for the different initial velocities 
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Fig 8: Kinetic energy normalized for the different initial velocities 
First self-contact: 
 Initial velocity = 5 ms-1: displacement = 120 mm; 
 Initial velocity = 10 ms-1: displacement = 94.15 mm. 
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Example 4 - Airbag 
 
Summary 
 
 
This example deals with the deployment of a chambered airbag modeled by monitored volumes 
using communications. The airbag is initially folded along four fold lines. The fabric is meshed with 
shell elements which undergo an elastic orthotropic behavioral test. Perfect gas is injected into a 
central chamber via an inflator with the air flow through the connected chambers being simulated. 
The chambers inflate while the airbag is deploying. 
In the self-impacting interface definition, the action of the Inacti flag to deactivate stiffness in the 
case of initial penetration is studied in order to significantly increase the time step. An adequate gap 
enables to pass from a kinematic interface time step to a higher element time step. 
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Title 
Airbag 
 
Number 
4.1 
Brief Description 
A chambered airbag folded along four fold lines is deployed. 
Keywords 
 Orthotropic shell 
 Monitored volumes and communicating airbags 
 /MAT/GAS 
 /PROP/INJECT1 
 Material law 0 and type 7 interface 
 Hierarchy organization 
RADIOSS Options 
 Monitored volume with communications (/MONVOL/COMMU1) 
 Interface (/INTER/ with Inacti flag) 
Input File 
Inactiv_0_Gap0.1: 
<install_directory>/demos/hwsolvers/radioss/04_Airbag/Inacti0_Gap01/AIRFIX* 
Inactiv_5_Gap0.3: 
<install_directory>/demos/hwsolvers/radioss/04_Airbag/Inacti5_Gap03/AIRBAG* 
Inactiv_5_Gap1.5: 
<install_directory>/demos/hwsolvers/radioss/04_Airbag/Inacti5_Gap15/AIRBAG2* 
Technical / Theoretical Level 
Beginner 
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Overview 
 
 
Aim of the Problem 
The purpose of this example is to deal with monitored volumes using communications on a simple 
airbag model. Methods for increasing the time step are considered. 
Physical Problem Description 
A 30-liter airbag is folded along the four fold lines. The following examples illustrate the airbag 
folded and deployed. 
 
Fig 1: Folded airbag Fig 2: Deployed airbag 
The fabric thickness is 0.33 mm and is modeled using an elastic orthotropic material law 
(/MAT/LAW19) with the following properties: 
 Density: 0.85x10-3 g/mm3 
 Young’s Modulus: 500 MPa in both directions 
 Shear Modulus: 10 MPa 
 Reduction factor: 0.001 
The property set is /PROP/SH_ORTH (shell orthotropic, type 9), using one integration point. 
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Analysis, Assumptions and Modeling Description 
 
 
Modeling Methodology 
 
Fig 3: Overall mesh of the structure (folded and deployed). 
The model is divided into two subsets: the fabric layers and the communication surfaces. 
The fabric surface is then divided into 9 subsets, one for each monitored volume. Each "monitored 
volume" is further divided into two parts. All the parts of the layer of fabric have the same Type and 
MID. 
The same properties apply for the communication surfaces. 
 
Fig 4: Folder airbag with communications. 
The airbag is modeled using 9 communicating volumes in order to simulate the air flow through the 
folds and the behavioral differences within the airbag when unfolding. The communicating surfaces 
between the volumes are simulated using dummy membranes. The dummy membranes are 
modeled using shells with fictitious material (/MAT/LAW0). 
RADIOSS Options Used 
A monitored volume is defined as a surface area having one or more shell property sets and where 
the surface must be closed. The monitored volume used is a COMMU1 type for airbags using 
communications (chambered, with communications, of the folder airbag type). For further details 
about monitored volumes, see the RADIOSS Theory Manual. 
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The main properties for this type are: 
 Volumetric damping factor: 0.001 g.mm-1ms-1 . 
 External pressure: 0.1 MPa 
 Constant perfect gas: 1.4 
 Specific heat at constant pressure: 926 mJ/g (This is the specific heat coefficient related to 
mass) 
 Temperature: 780 K. 
 Communication area: total (Acom =1 and Scom =0) 
 Time to deflate vent hole: 1030 ms 
The gas molecular weight and specific heat coefficients are defined in /MAT/GAS (using MASS type): 
 Molecular weight of gas MW: 30.09204 g/kmol (AIR) 
 Specific heat at constant pressure: 926 mJ/g (specific heat coefficient related to mass) 
Specific input for the central chamber one (inflator): 
 Vent hole membrane surface area is 1000 mm2 (Avent =0) and is immediately activated. 
 Relative vent deflation pressure: 0.0002 
 Number of injectors: 1 (Njet =1; Ijet =0) 
Using /PROP/INJECT1 to described mass inject: 
 Final injected mass is 46 g injected into the central chamber (FscaleM and FscaleT =1). Two 
functions define the mass and temperature of the injected gas compared with time (function 
identifiers: fct_IDM and fct_IDT). 
Time (ms) 0 2 4 5 6 8 11 12 15 19 28 30 106 
Mass (g) 0 6 11 14 17 22 29 31 36 41 45 46 46 
Injected mass function. 
Time (ms) 0 106 
Temperature (K) 780 780 
Temperature of injected gas function. 
Interface 
Taking into account the fabric is self-impacting with itself, a self-impacting interface must be used. 
The interface’s Block Format definition is made: defining the master surface (/SURF/PART), then 
defining the slave nodes for all nodes on this surface (/GRNOD/SURF). 
The distance between the fabric layers before unfolding is very small. In order to avoid initial 
penetration, the gap required is approximately 0.1 mm, thus enabling the time step to considerably 
decrease when such a gap is chosen. 
By using Inacti =5, a 0.3 mm gap is chosen. Any initial penetration below 0.2 mm (two-thirds of the 
input gap) is ignored (it is strongly recommended to verify that no initial penetration is above this 
value). 
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Simulation Results and Conclusions 
 
 
Curves and Animations 
In order to demonstrate the interest of the Inacti flag, the same model was run with Inacti at a 
value of 0, with a gap of 0.1 mm (no initial penetration). 
 
Fig 5: Comparison between option Inacti = 5 and Inacti = 0 
Using Inacti = 5, the minimum time step is around 10-3 ms. When not using this option, the 
minimum time step is around 2x10-4 ms. For the full model, the number of cycles may be divided 
up into 10 or more. Furthermore, the model is numerically less sensitive. 
The time step is monitored by the interface time step (kinematic) for up to 40 ms despite the 
unfolding and the fact that there is no energy contact from 7.8 ms. In order to transfer into the 
element time step and to reduce computation time, it is advisable to increase the gap so the 
kinematic step becomes higher than the element step. 
Time-stepkinetic < 0.9 x GAP / Nodal_velocityrelative (using scale factor = 0.9) 
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The time step is only low during the unfolding phase (before 10 ms) with a gap equal to 1.5 mm. 
 
Inacti flag = 5 Inacti flag = 0 
GAP = 0.3 mm GAP = 1.5 mm GAP = 0.1 mm 
Error on energy -16.3% -19.6% -15.5% 
Elapsed Time [s] 57.5 47.8 78.58 
Airbag deploy completely deploy completely deploy incompletely deploy 
 
Fig 6: Time step obtained with GAP = 0.3 mm and GAP = 1.5 mm (Inacti = 5). 
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Fig 7: Contact energy with GAP = 0.3 mm and GAP = 1.5 mm (Inacti = 5). 
It is obvious that a gap of 1.5 mm generates an increase in the contact force. However, the 
additional error on energy remains quite low and is acceptable. 
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Fig 8: Time history of pressure. 
 
Fig 9: Time history of volume. 
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Animations 
 
Fig 10: Central chamber is inflating. 
 
Fig 11: All chambers are inflating. 
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Fig 12: Airbag is deployed 
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Example 5 - Beam Frame 
 
Summary 
 
 
A beam frame with clamped extremities receives an impact at its mid-point from a pointed mass 
having initial velocity. The material is subjected to the elasto-plastic law of Johnson-Cook. The 
model is meshed with beam elements. An infinite rigid wall with only one slave node, including the 
impacted node, is subjected to the initial velocity. This example is considered a dynamic problem 
and the explicit solver is used. 
The explicit approach leads to finding a quasi-static equilibrium of the structure after impact.
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Title 
Beam-frame 
 
Number 
5.1 
Brief Description 
A beam frame receives an impact from a mass having initial velocity. 
Keywords 
 Beam 
 Rigid wall 
 Plasticity and Johnson-Cook material (/MAT/LAW2) 
RADIOSS Options 
 Boundary conditions (/BCS) 
 Initial velocities (/INIVEL) 
 Beam element (/PROP/BEAM) 
 Rigid wall (/RWALL) 
Input File 
Beam_frame: <install_directory>/demos/hwsolvers/radioss/05_Beam-frame/FRAME* 
Technical / Theoretical Level 
Beginner 
Overview 
 
 
Aim of the Problem 
The purpose of this example is to perform a static analysis using beam elements. 
Physical Problem Description 
A pointed mass (3 kg) makes an impact at point O of a beam frame (see Fig 1 for the geometry) 
using a speed of 10 ms-1 in the Z direction. The beams are made of steel and each beam section is 
square-shaped (each side being 6 mm long). 
 
Fig 1: Geometry of the frame. 
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Dimensions are: AB = BC = CD = BE = BF = E’C = CF’ = 90 mm. 
Points A, D, E, F, E’, and F’ are fixed. 
The beams have the following properties: 
 Cross section: 36 mm2 
 Moments of inertia in Y and Z: 108 mm4 
 Moments of inertia in X : 216 mm4 
The steel material used has the following properties: 
 Density: 0.0078 g/mm3 
 Young’s modulus: 200 000 MPa 
 Poisson’s ratio: 0.3 
 Yield stress: 320 MPa 
 Hardening parameter: 134.65 MPa 
 Hardening exponent: 1.0 
All other coefficients are set to default values. Plasticity is taken into account using Law 2 without 
failure. 
Analysis, Assumptions and Modeling Description 
 
 
Modeling Methodology 
The mesh is a regular beam mesh, each beam being 9 mm long (total = 70 beams). 
 
Fig 2: Mesh of the frame showing the position of the nodes. 
RADIOSS Options Used 
The impacting mass is simulated using a sliding rigid plane wall (/RWALL) having an initial velocity 
of 10 ms-1 and a mass of 3000 g. Only one slave node exists: the node O to simulate a point 
impact. 
Points A, F, F', D, E and E' are fully fixed. 
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Fig 3: Boundary conditions Fig 4: Rigid wall type infinite plane 
Simulation Results and Conclusions 
 
 
Curves and Animations 
The main results refer to the time history of points B and O with regard to displacements and 
velocities. 
 
Fig 5: Displacements of points B and O. 
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Fig 6: Velocity of points B and O (stabilization). 
 
Fig 7: Normal and shear force on beam element 15 (near to point O). 
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Fig 8: Energy assessment (stability reached at in 6 ms). 
 
Fig 9: Node displacement (max. = 30.96 mm). 
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Fig 10: Plastic strain (max. = 20.1%). 
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Example 6 - Fuel Tank 
 
 
Summary 
 
 
The fluid-structure interaction and the fluid flow are studied in cases of a fuel tank sloshing and 
overturning. A bi-phase liquid-gas material with an ALE formulation is used to define the interaction 
between water and air in the fuel tank. 
In the case of sloshing, the fuel tank is subjected to a horizontal deceleration. The fuel tank 
container is modeled with a Lagrangian formulation and undergoes an elasto-plastic material law. 
Fluid structure coupling is taken into account. 
The overturning of the fuel tank is studied by applying a variable deceleration. The tank container is 
not modeled as the boundary nodes are fixed. The Eulerian formulation is used. 
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6.1 - Fluid Structure Coupling 
 
Title 
Fuel tank - Fluid 
Structure Coupling 
 
Number 
6.1 
Brief Description 
Sloshing inside a fuel tank by simulating the fluid structure coupling. The tank deformation is 
achieved by applying an imposed velocity on the left corners. Water and air inside the tank are 
modeled with the ALE formulation. The tank container is described using a Lagrangian formulation. 
Keywords 
 Fluid structure coupling simulation, and ALE formulation 
 Shell and brick elements 
 Hydrodynamic and bi-phase liquid gas material (/MAT/LAW37) 
RADIOSS Options 
 ALE boundary conditions (/ALE/BCS) 
 J. Donea Grid Formulation (/ALE/GRID/DONEA) 
 Boundary conditions (/BCS) 
 Gravity (/GRAV) 
 Imposed velocity (/IMPVEL) 
 ALE material formulation (/ALE/MAT) 
Input File 
Fluid_structure_coupling: <install_directory>/demos/hwsolvers/radioss/06_Fuel_tank/ 
1-Tank_sloshing/Fluid_structure_coupling/TANK* 
Technical / Theoretical Level 
Advanced 
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Overview 
 
 
Aim of the Problem 
A numerical simulation of fluid-structure coupling is performed on sloshing inside a deformable fuel 
tank. This example uses the ALE (Arbitrary Lagrangian Eulerian) formulation and the hydrodynamic 
bi-material law (/MAT/LAW37) to model interaction between water, air and the tank container. 
Physical Problem Description 
A rectangular tank made of steel is partially filled with water, the remainder being supplemented by 
air. The initial distribution pressure is known and supposed homogeneous. The tank container 
dimensions are 460 mm x 300 mm x 10 mm, with thickness being at 2 mm. 
Deformation of the tank container is generated by an impulse made on the left corners of the tank 
for analyzing the fluid-structure coupling. 
 
Fig 1: Problem description. 
The steel container is modeled using the elasto-plastic model of Johnson-Cook law (/MAT/LAW2) 
with the following parameters: 
 Density: 0.0078 g/mm3 
 Young’s modulus: 210000 MPa 
 Poisson’s ratio: 0.29 
 Yield stress: 180 MPa 
 Hardening parameter: 450 MPa 
 Hardening exponent: 0.5 
The material air-water bi-phase is described in the hydrodynamic bi-material liquid-gas law 
(/MAT/LAW37). Material law 37 is specifically designed to model bi-material liquid gas. 
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The equations used to describe the state of viscosity and pressure are: 
 Viscosity: 
 
 Liquid EOS: 
 
where, 
 Gas EOS: 
 
The equilibrium is defined by: Pl = Pg 
Where, Sijis the deviatoric stress tensor and eij is the deviatoric strain tensor. 
Material parameters are: 
 For liquid: 
0l
 Liquid reference density: 0.001 g/mm3 
Cl Liquid bulk modulus: 2089 N/mm
2 
al Initial mass fraction liquid proportion: 100% 
 Shear kinematic viscosity (= / 0l

): 0.001 mm2/ms 
 For gas: 
0g
 Gas reference density: 1.22x10-6 g/mm3 
g Shear kinematic viscosity (= / 
0g
): 0.00143 mm2/ms 
 Constant perfect gas: 1.4 
P0 Initial pressure reference gas: 0.1 N/mm
2 
The main solid type 14 properties for air/water parts are: 
 Quadratic bulk viscosity/linear bulk viscosity: 10-20 
 Hourglass bulk coefficient: 10-5 
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Analysis, Assumptions and Modeling Description 
 
 
Modeling Methodology 
Air and water are modeled using the ALE formulation and the bi-material law (/MAT/LAW37). The 
tank container uses a Lagrangian formulation and an elasto-plastic material law (/MAT/LAW2). 
 
Fig 2: Air and water mesh (ALE brick elements). 
 
Fig 3: Tank container mesh (shell elements). 
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Using the ALE formulation, the brick mesh is only deformed by tank deformation the water flowing 
through the mesh. The Lagrangian shell nodes still coincide with the material points and the 
elements deform with the material: this is known as a Lagrangian mesh. For the ALE mesh, nodes 
on the boundaries are fixed in order to remain on the border, while the interior nodes are moved. 
RADIOSS Options Used 
Velocities (/IMPVEL) are imposed on the left corners in the X direction. 
 
Table 1: Imposed velocity versus time curve 
Velocity (ms-1) 0 5 0 0 
Time (ms) 0 12 12.01 50 
 
 
Fig 4: Kinematic condition: imposed velocities. 
Regarding the ALE boundary conditions, constraints are applied on: 
 Material velocity 
 Grid velocity 
All nodes, except those on the border have grid (/ALE/BCS) and material (/BCS) velocities fixed in 
the Z-direction. The nodes on the border only have a material velocity (/BCS) fixed in the Z-
direction. 
Both the ALE materials air and water must be declared ALE using /ALE/MAT. Lagrangian material is 
automatically declared Lagrangian. 
The /ALE/GRID/DONEA option activates the J. Donea grid formulation to compute the grid velocity. 
See the RADIOSS Theory Manual for further explanations about this option. 
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Simulation Results and Conclusions 
 
 
Curves and Animations 
Fluid – Structure Coupling 
 
Fig 5: X – momentum variation for each part. 
Kinematic conditions generate oscillations of the structure. 
 
Fig 6: Density attached to the various brick elements.
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Fluid Structure Coupling Time = 0 ms 
Density 
 
Velocity 
 
 
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Fluid Structure Coupling Time = 12 ms 
Density 
 
Velocity 
 
 
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Fluid Structure Coupling Time = 42 ms 
Density 
 
Velocity 
 
 
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6.2 - Fluid Flow 
 
Title 
Fuel tank - Fluid flow 
 
Number 
6.2 
Brief Description 
Fuel tank overturning with simulation of the fluid flow. The reversing tank is modeled using 
horizontally-applied gravity. The tank container is presumed without deformation and only the 
water and air inside the tank are taken into consideration using the ALE formulation. 
Keywords 
 Fluid flow simulation and ALE formulation 
 Brick elements 
 Hydrodynamic and bi-phase liquid gas (/MAT/LAW37) 
RADIOSS Options 
 ALE boundary conditions (/ALE/BCS) 
 J. Donea Grid Formulation (/ALE/GRID/DONEA) 
 Gravity (/GRAV) 
 ALE material formulation (/ALE/MAT) 
Input File 
Fluid_flow_gravity_1: <install_directory>/demos/hwsolvers/radioss/06_Fuel_tank/ 
2-Tank_overturning/Fluid_flow_1/PFTANK* 
Fluid_flow_gravity_2: <install_directory>/demos/hwsolvers/radioss/06_Fuel_tank/ 
2-Tank_overturning/Fluid_flow_2/PFTANK* 
Technical / Theoretical Level 
Advanced 
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Overview 
 
 
Aim of the Problem 
The fluid flow is studied during the fuel tank overturning. This example uses the ALE (Arbitrary 
Lagrangian Eulerian) formulation and the hydrodynamic bi-material law (/MAT/LAW37) to simulate 
interaction between water and air. The tank container is presumed without deformation and it will 
not be modeled. 
Physical Problem Description 
A rectangular tank is partially filled with water, the remainder being supplemented by air. The tank 
turns once around itself on the Y-axis. The overturning is achieved by defining a gravity field in the 
X direction, which is parallel to the liquid gas interface. All gravity is applied in other directions. The 
initial distribution pressure is already known and supposed homogeneous. The tank dimensions are 
460 mm x 300 mm x 10 mm. 
 
Fig 7: Problem description. 
The example deals with two loading cases: an instantaneous rotation of the fuel tank by 90 degrees 
(gravity function 1) and a progressive rotation (gravity function 2). 
The main material properties for the ALE bi-phase air-water are: 
 Air density: 1.22x10-6 g/mm3 
 Water density: 0.001 g/mm3 
 Gas initial pressure: 0.1 MPa 
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Analysis, Assumptions and Modeling Description 
 
 
Modeling Methodology 
The bi-material air-water is described in the hydrodynamic material law (/MAT/LAW37). See 
previous section for information about this law, including full input data. 
This loading case does not require a tank container mesh and the model, air and water are only 
comprised of the brick element using an ALE formulation. 
 
Fig 8: Air and water mesh (ALE bricks). 
Using the ALE formulation, brick mesh is only deformed by the tank deformation, the water flowing 
through the mesh. The Lagrangian shell nodes still coincide with the material points, while the 
elements are deformed with the material: this is the Lagrangian mesh. For the ALE mesh, nodes on 
boundaries are fixed to remain on the border, while the interior nodes are moved. 
RADIOSS Options Used 
Regarding the ALE boundary conditions (/ALE/BCS), constraints are applied on: 
 Material velocity 
 Grid velocity 
All nodes inside the border have grid and material velocities fixed in the Z direction; the nodes on 
the left and right sides have a material velocity fixed in the X and Z directions, while the nodes on 
the high and low sides have a material velocity fixed in the Y and Z directions. The grid velocity is 
fully fixed on the border, just as the material velocity is fixed on the corners. 
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A function defines gravity acceleration in the X direction compared with time in order to simulate 
the rotation effect. Gravity is activated by /GRAV. Two cases are studied depending on the 
acceleration function selected: 
 
Fig 9: Variable acceleration function 1 Fig 10: Constant acceleration function 2 
Gravity is considered for all nodes. 
 Both ALE materials air and water must be declared as ALE using /ALE/MAT. Lagrangian 
material is automatically declared as Lagrangian. 
 The /ALE/GRID/DONEA option activates the J. Donea grid formulation in order to compute grid 
velocity. See the RADIOSS Theory Manual for further explanation about this option. 
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Simulation Results and Conclusions 
 
 
Model with Constant Acceleration 
(Gravity function 1) 
Time = 170 ms 
Density 
 
Velocity 
 
 
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Model with Constant Acceleration 
(Gravity function 1) 
Time = 280 ms 
Density 
 
Velocity 
 
 
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Model with Variable Acceleration 
(Gravity function 2) 
Time = 50 ms 
Density 
 
Velocity 
 
 
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Model with Variable Acceleration 
(Gravity function 2) 
Time = 70 ms 
Density 
 
Velocity 
 
Conclusion 
 
 
This example studied hydrodynamic bi-material using Law 37 in RADIOSS, using ALE and Eulerian 
formulations. The application of boundary conditions in ALE formations and handling the fluid-
structure interaction were discussed. Furthermore, the results obtained correctly represent the 
physical problem. 
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Example 7 - Pendulums 
 
Summary 
 
 
The purpose of this example is to simulate the oscillation and wave propagation of a group of 
pendulums, arranged in a line, when impacted at one end. The material is described as being 
elastic. Two models are used to simulate two different physical problems: 
 The 2D model represents the infinite cylindrical mass for pendulums 
 The 3D model is necessary for determining the spherical mass 
The quality of the model first depends on how contact is managed. For the 2D model, a simple type 
5 interface with a plane facet is used. For the 3D model, however, a type 16 interface using the 
Lagrange Multipliers method is used. 
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Title 
Pendulums 
 
Number 
7.1 
Brief Description 
Five pendulums in line, initially in contact with each other, are struck by a sixth one. The shock 
wave and oscillating motion are observed. 
Keywords 
 Tri-dimensional analysis, truss, brick, and 16-node thick shell 
 Type 16 interface (Node to brick contact) 
 Elasticity, momentum transmission, shock wave propagation, and multiple-impacts 
 Bi-dimensional analysis, plane strain, type 5 interface, and quad element 
RADIOSS Options 
 Bi-dimensional analysis (/ANALY) 
 Gravity (/GRAV) 
 Type 16 interface (/INTER/LAGMUL/TYPE16) and type 5 (/INTER/TYPE5) 
Compared to / Validation Method 
 Experimental and analytical results 
Input File 
Tri-dimensional_analysis: 
<install_directory>/demos/hwsolvers/radioss/07_Pendulums/3D_model/PENDULUMS_3D* 
Bi-dimensional_analysis: 
<install_directory>/demos/hwsolvers/radioss/07_Pendulums/Plan_strain_model/ 
PENDULUMS_2D* 
Technical / Theoretical Level 
Medium 
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Overview 
 
 
Aim of the Problem 
The purpose of this example is to study the shock wave propagation and the momentum transfer 
through several bodies, initially in contact with each other, subjected to multiple-impact. The 
process of collision and the energetic behavior upon impact are delineated using a tri-dimensional 
model. A plane strain assumption can be used as a compliment to this study, whereby a bi-
dimensional model using fine mesh enables shock wave propagation and the mechanics contact to 
be shown in a qualitative manner. 
Physical Problem Description 
A metal ball strikes a line of five balls, initially in contact with each other. The momentum is 
transferred from pendulum to pendulum until reaching the last one at the opposite end. The system 
is subjected to gravity. This results in the end pendulums alternate oscillating for half the time 
period. 
The following system is used: mm, ms, g, N, MPa. 
 
Fig 1: Description of the problem. 
The left pendulum has an initial angle of 45 degrees in relation to the vertical. The material used is 
aluminum alloy which behaves like a linear elastic law (/MAT/LAW1) during impact. 
The properties are defined as follows: 
 Young’s modulus: 70000 MPa 
 Poisson’s ratio: 0.33 
 Density: 0.0027 g.mm-3 
The geometrical characteristics of the balls and trusses are: 
 Truss: 
- Length: 124.6 mm 
 Ball: 
- Radius: 25.4 mm (massball = 182.5g) 
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Analysis, Assumptions and Modeling Description 
 
 
Two approaches 2D and 3D are used to provide complementary simulation results. 
Modeling Methodology: 3D Model 
Brick and thick shell elements are used to create the 3D model for balls. The quadratic 16-node 
thick shell element is used to model the external surface of the balls. However, the core of each ball 
is modeled using 8-node solid elements. 
 
Fig 2: Tri-dimensional mesh in initial state. 
The modeling technique used enables to ensure contact between the quadratic surfaces. 
Figure 3 shows the mesh used for balls. The mesh uses a hypercube mesh topology combining brick 
and 16-node thick shell elements. 
 
Fig 3: Mesh for balls (brick and 16-node thick shell). 
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The type 16 interface using the Lagrange Multipliers method is employed to model contacts between 
the nodes and the quadratic elements’ surface. An interface must be defined for each ball (five 
interfaces). 
 
Fig 4: Slave nodes and master surfaces defined for the type 16 interface. 
No gap is required for the type 16 interface, enabling the contact condition to be exactly satisfied. 
RADIOSS Options Used 
Gravity is applied to all nodes. A function defines the gravity acceleration in the Z direction 
compared with time. Gravity is activated by the /GRAV option. 
 
Fig 5: Gravity loading (-0.00981 mm.ms-2 ). 
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The upper extremities of the trusses are fixed in Y and Z translations and in Y and Z rotations. 
 
Fig 6: Boundary conditions on the upper extremities of trusses. 
Modeling Methodology: 2D Model 
By adopting a plane strain approach, a 2D model is used (N2D3D = 2 in the /ANALY option set in the 
input file). The plane strain analysis defines the X-axis as the plane strain direction. 
The mesh consists of 2D solid elements (quads). The dimension of the quad is about 0.5 mm for 
balls. 
 
Fig 7: 2D mesh in the initial state. 
Normal vectors of quad elements should have the same orientation to avoid negative volumes. 
Quad elements undergo a type 14 general solid property. 
The contact between the external segments of the quads is modeled five times using a type 5 
interface. 
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Fig 8: Master segments and slave nodes defined for type 5 interfaces. 
Type 5 interface uses the Penalty method for a master segment contact (blue side) to the slave 
node (red side). The gap is set to 0.1 mm as the initial interval between the masses. The contact is 
sliding using a Coulomb friction coefficient that is equal to zero. 
Type 7 general interface is not available in a 2D analysis. 
RADIOSS Options Used 
The upper extremities of the trusses are fixed in Y and Z translations. The 2D conditions are 
automatically taken into account with N2D3D = 2 in /ANALY. 
Gravity is applied to all nodes. A constant function (-0.00981 mm.ms-2) defines the gravity 
acceleration in the Z direction compared with time. Gravity is activated by /GRAV. 
For the 2D analysis, the rigid body /RBODY option is not available. 
For the purpose of this example, the followingnumbers are assigned to the balls: 
 
Fig 9: Ball numbers. 
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Simulation Results and Conclusions 
 
 
2D Approach: Dynamic System Analysis 
Maintaining Energy and Oscillations 
Figure 10 shows the kinetic energy variation of the model. When considering energy, the system 
behaves as a simple pendulum. 
 
Fig 10: Global energy assessment. 
When the pendulum mass is released at time t=0, the No. 6 end ball has maximum potential energy 
and null kinetic energy. Ball 6 achieves maximum velocity before striking the five other pendulums. 
For a moderate case that is without loss, you have: 
 
Where, h is the vertical displacement of the ball’s center, V is the velocity and m is the mass. 
The maximum kinetic energy is reached for: h = hmax = I(1 - cos(45)) = 43.934 mm 
Analytical solution: 
EKINETICmax = mghmax = 182.5 * 0.00981 * 43.934 = 78.656 mJ 
Simulation results: 
EKINETICmax = 78.655 mJ (time = 203.33 ms, impact balls 6 and 5) 
 
EKINETICmax = 72.478 mJ (time = 612.5 ms, impact balls 1 and 2) 
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Maintaining the kinetic energy in the system is not entirely satisfactory, due to the energy contact 
being dissipated during impact. 
The two extreme pendulums alternate, oscillating for half of the time period. The velocity of the 
middle balls in comparison to time is shown in Fig 11. 
 
Fig 11: Velocity transmission between the end balls 1 and 6. 
Velocity is transferred from pendulum to pendulum until reaching the end one. 
Equation of Motion 
The relative motion of a simple pendulum can be described using the equation: 
 
where, is the system’s pulsation: 
 
 
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Fig 12: Pendulum motion. 
Such analytical equation can be corroborated with regard to the end balls No. 1 and 6. 
Rotations and rotational accelerations are indicated from the nodes located at the upper end of 
the trusses. 
 
Fig 13: Verification of the equation for ball 6. 
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Fig 14: Verification of the equation for ball 1. 
The numerical results have an average correlation in relation to the analytical solution, due to the 
dynamic response of the nodal acceleration saved in the Time History. 
Energetic Behavior upon Impact 
Lets consider the interval [203,33 ms and 204,11 ms] where multiple impacts occur from balls No. 
6 to 1. 
 
As shown in Fig 15, the internal energy stored in the system is released after each impact, in line 
with the defining balls linear material law. The kinetic energy is transferred from pendulum to 
pendulum. 
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Fig 15: Global energy assessment during multiple impacts. 
The 16-node thick shells are elements, which do not suffer hourglass deformation. Therefore, the 
low kinetic energy lost during multiple impact is due to the dissipated contact energy (-2.47mJ). 
The external work of the gravity remains constant (78.655mJ). 
The following animations separately illustrate: 
 the motion of the pendulums 
 the kinetic energy transmission 
 the stress wave propagation 
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Balls Motion (Oscillations) 
 
 
 
 
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Momentum transmission from pendulum to pendulum (cutting plane X = 0): 
Velocity Norm 
 
 
 
 
 
 
 
Time for total transmission: 0.78 ms Maximum = 1.08588 m.s-1. 
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Shock wave propagation during multiple impact (cutting plane X=0): 
von Mises Stress Wave 
 
 
 
 
 
 
Time for transmission: 0.78 ms Maximum = 17.7062 MPa. 
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2D Approach: Multiple Impact Analysis 
In this section covers the mechanics contact across a 6-ball chain. 
The plane strain assumption changes the physical problem. Nevertheless, this case study is an 
interesting example of a system undergoing several shocks. 
 
Fig 16: A 6-ball chain system. 
The force between balls compared with time is shown in Fig 17. Existence of a time interval where 
forces’ contacts are not at zero. 
 
Fig 17: Forces’ contact between balls compared with time (contact starts at t’=0 ms). 
This process leads to multiple impacts. It corroborates the experimental observations, where the 
theory was well estimated. Based on an Impulse Correlation Ratio (ICR), a regularized system of an 
N-ball chain using an elastic contact spring gives similar results. 
 
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 Reference results: [V. Acaray, B. Brogliato/Second MIT Conference on Computational Fluid 
and solid Mechanics] 
von Mises stress wave propagation from ball to ball during the multiple impact period (isostep 
values): 
 
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Conclusion 
 
 
The impact between several pendulums in line was studied using RADIOSS. Two models 
representing physical problems were studied: 
(i) a global analysis using a relatively coarse mesh with 3D elements 
(ii) a 2D model using a fine mesh 
In the first case, the energy assessment and the wave propagation are studied. The mesh used is 
not fine enough for studying the contact effects, due to the fact that 3D represents a high cost 
model and using a fine mesh dramatically increases the computation time. The results are 
compared to an analytical solution where the pendulum system is assimilated to a simple 
pendulum. 
The 2D analysis concentrates on contact between the balls. There still exists an analytical solution 
though for a chain of three balls, but which can be generalized for the purpose of this example. The 
results obtained by simulation and theory demonstrate the validity of the numerical results obtained 
by RADIOSS. 
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Example 8 - Hopkinson Bar 
 
Summary 
 
 
Precise data for high strain rate materials is necessary to enable the accurate modeling of high-
speed impacts. The high strain rate characterization of materials is usually performed using the split 
Hopkinson Pressure Bar within the strain rate range 100-10000 s-1. Using the one-dimensional 
analysis of the Hopkinson bar experiment, it is assumed that the object deforms under uni-axial 
stress, the bar object interfaces remain planar at all times, and the stress equilibrium in the object 
is achieved using travel times. The RADIOSS explicit finite element code is used to investigate these 
assumptions. 
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Title 
Split Hopkinson 
pressure bar testing 
 
Number 
8.1 
Brief Description 
The high strain rate tensile behavior of the 7010 aluminum alloy is studied using the Hopkinson 
pressure bar technique (stress wave). 
Keywords 
 Axisymmetrical analysis and quad elements 
 High strain rate and Split Hopkinson Pressure Bar (SHPB) 
 Wave propagation and stress pulse 
 Elastic model (/MAT/LAW1) and Johnson-Cook elasto-plastic model (/MAT/LAW2) 
RADIOSS Options 
 Axisymmetrical analysis (/ANALY) 
 Boundary conditions (/BCS) 
 Imposed velocities (/IMPVEL) 
Compared to / Validation Method 
 Experimental data 
Input File 
High_strain_rate: 
<install_directory>/demos/hwsolvers/radioss/08_Hopkinson_Bar/High_strain_rate/SHPB_H* 
Low_strain_rate: 
<install_directory>/demos/hwsolvers/radioss/08_Hopkinson_Bar/Low_strain_rate/SHPB_L* 
Technical / Theoretical Level 
Advanced 
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Overview 
 
 
Aim of the Problem 
In order to model and predict the behavior of material during impact, the responses at very high 
strain rates should be studied. The Split Hopkinson Bar is an inexpensive device for performing high 
strain-rate experiments [1]. This equipment consists of four long pressure bars: 
 the striker bar 
 the incident bar 
 the transmission bar 
 the drop bar 
The object is sandwiched between the transmission and the incident bar. Assuming that the wave 
propagation in the bar is non-dispersive, the force and displacement upon contact between the bar 
and the object can be obtained from the strains measured through experience. In this example, the 
dynamic tensile behavior, achieved through experience of the 7010 aluminum alloy with a Split 
Hopkinson Pressure Bar (SHPB) is compared to numerical simulations. Two cases are studied at the 
strain rates of 80 s-1 (low rate) and 900 s-1 (high rate) respectively. At high strain rates, experience 
shows that the stress flow significantly increases by more than 30% with the strain rate increasing; 
thus demonstrating strain rate dependence in aluminum alloys in general. For the strain rates’ 
range applied here, an existing Johnson-Cook model is used to describe the stress flow as a strain 
and strain rate function. Failure is not taken into account. 
Physical Problem Description 
The Split Hopkinson Pressure Bar technique corresponds to a high strain rate deformation of the 
aluminum alloy at high stress. Figure 1 shows a diagram of the basic Hopkinson bar setup. It 
consists of two cylindrical bars of the same diameter, respectively called Input and Output bars. 
 
Fig 1: Hopkinson bar device. 
The objects material undergoes an isotropic elasto-plastic behavior which can be reproduced using a 
Johnson-Cook model (/MAT/LAW2). The steel bars and the striker follow a linear elastic law 
(/MAT/LAW1). 
The following system is used: mm, ms, g, N, MPa. 
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Fig 2: Object geometry and cross-section (dimensions in mm). 
Johnson-Cook Model 
The Johnson-Cook model describes the stress in relation to the plastic strain and the strain rate 
using the following equation: 
 
where: 
 is the strain rate 
0 is the reference strain rate 
p is the plastic strain (true strain) 
a is the yield stress 
b is the hardening parameter 
n is the hardening exponent 
c is the strain rate coefficient 
The two optional inputs, strain rate coefficient and reference strain rate, must be defined for each 
material in /MAT/LAW2 in order to take account of the strain rate effect on stress, that is the 
increase in stress when increasing the strain rate. The constants a, b and n define the shape of the 
strain-stress curve. 
In the documents entitled CRAHVI, G4RD-CT-2000-00395, D.1.1.1, Material Tests – Tensile 
properties of Aluminum Alloys 7010T7651 and AU4G Over a Range of Strain Rates, the behavior of 
the 7010 aluminum alloy can be described according to the relations: 
 for strain rates below 80 s-1 
 for strain rates exceeding 80 s-1 up to 3000 s-1 
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Fig 3: Yield curve of the Johnson-Cook model: 
The material properties of the object are: 
 Young’s modulus: 73000 MPa 
 Poisson’s ratio: 0.33 
 Density: 0.0028 g/mm3 
The material used for the bars and projectile is type 1 (linear elastic) with the following properties: 
 Young’s modulus: 210000 MPa 
 Poisson’s ratio: 0.33 
 Density: 0.0078 g/mm3 
The geometrical characteristics of the bars and projectile are: 
Bars: 
 Length: 4 m 
 Diameter: 12 mm 
 
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Projectile: 
 Radius: 12 mm 
 Weight: 170 g 
 
High Strain Rate Test Method 
The object is screwed in between the incident and transmission bars. A stress pulse is introduced 
into the input bar through impact from a steel projectile on the steel disc attached to one end of the 
input bar. The impact generates a tensile wave which propagates along the input bar. Part of the 
wave is reflected and a part is transmitted via the object’s interface. The stress pulse continues 
through the object and into the transmitted bar. The wave reflections inside the sample enable the 
stress to be homogenized during the test. The strain associated with the output or transmitted 
stress wave is measured by the strain gauges on the output or transmitted bar. The strain gauges 
attached to the object gauge length, provide direct measuring of the true strain, and the true plastic 
strain in the object during the experiment. The transmitted elastic wave provides a direct force 
measurement to the bar object interfaces by way of the following relation: 
 
Where, Ebar is the modulus of the output bar, T is the strain associated with the output stress wave 
and the Sbar is the cross-section of the output bar. 
If the two bars remain elastic and wave dispersion is ignored, then the measured stress pulses can 
be assumed to be the same as those acting on the object. 
The engineering stress value in the object can be determined by the wave analysis, using the 
transmitted wave: 
 
Engineering stress can also be found by averaging out the force applied by the incident that is the 
reflected and transmitted wave, as shown in the equation: 
 
 
Where, I and R are the strains associated with input stress wave and T is the strain associated 
with output stress wave. 
True stress in the object is computed using the following relation (refer to Example 11 - Tensile Test 
for further details): 
 
The true strain rate is given by: 
 
True stress and true strain are evaluated up to the failure point. 
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Interface 1: F1 = Sbar ( I(t) + R(t)) = SbarEbar( I(t) + R(t)) 
Interface 2: F2 = Sbar T(t) = SbarEbar T(t) 
Balance in object: F1 = F2 ; 1(t) + R(t) = T(t) 
Engineering stress in object: object (t) = F1 / Sobject = F2 / Sobject 
Fig 4: 1D analysis. 
Strain Rate Filtering 
Because of the dynamic load, strain rates cause high frequency vibrations which are not physical. 
Thus, the stress-strain curve may appear noisy. The strain rate filtering option enables to dampen 
such oscillations by removing the high frequency vibrations in order to obtain smooth results. A cut-
off frequency for strain rate filtering (Fcut) is used with a value less than half of the sampling 
frequency (1/ This or 1/ Tsampling) defined in the Engine file (*_0001.rad) using the /TFILE option. 
Refer to Example 11 - Tensile Test for further details. 
The cut-off frequency is set at 100 kHz in this example. 
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Analysis, Assumptions and Modeling Description 
 
 
Modeling Methodology 
Taking into account the geometry’s revolution symmetry the material and the kinematic conditions, 
an axisymmetrical model is used (N2D3D = 1 in /ANALY set up in the Starter file). Y is the radial 
direction and Z is the axis of revolution. 
The mesh is made of 12054 2D solid elements (quads). The quad dimension is about 2 mm. 
 
Fig 5: Mesh of the axisymmetrical model with imposed velocities on the top of the input bar. 
RADIOSS Options Used 
Low extremity nodes of the output bar are fixed in the Z direction. The axisymmetrical condition on 
the revolutionary symmetry axis requires the blocking of the Y translation and X rotation. 
The projectile is modeledusing a steel cylinder with a fixed velocity in the direction Z. The required 
strain rate is taken into account by applying two imposed velocities, 1.7 ms-1 and 5.8 ms-1 in order 
to produce strain rate ranges in the of 80 s-1 and 900 s-1 (low and high rates) object. 
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True Stress, True Strain and True Strain Rate Measurement from Time History 
 
Fig 6: Nodes and quads saved for Time History. 
In the experiment, the strain gauge is attached to the object. In simulation, the true strain will be 
determined from 9040 and 6 nodes’ relative Z displacements (l0 = 3.83638 mm). 
The true stress can be given using two data sources. The first methodology consists of using the 
equation previously presented, based on the assumption of the one-dimensional propagation of bar-
object forces. The engineering strain t associated with the output stress wave is obtained from the 
Z displacement of nodes located on the output bar. The true plastic strain is extracted from the 
quads on the object, saved in the Time History file. True stress can also be measured directly from 
the Time History using the average of the Z stress quads 6243, 6244, 6224 and 6235. It should be 
noted that the section option is not an available option with the quad elements. 
The strain rate can be calculated from either the true plastic strain of quads saved in /TH/QUAD or 
from the true strain true. 
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Table 1: Relations used in the analysis 
 High Rate Testing 
True stress 
 
Z stress average from quads saved in 
/TH 
True strain 
 
True strain rate 
 
 
Simulation Results and Conclusions 
 
 
The purpose of this test is to obtain the results observed in experiments with a Johnson-Cook 
model. The increase of stress is expected to equal approximately 30% compared to the low strain 
rate test. 
Experimental Data 
Experimental results show that the variation of the true tensile flow stress compared with the true 
strain is approximately equivalent to a strain rate between 80 s-1 and 100 s-1. The reference strain, 
 in the Johnson-Cook model is set to 0.08 ms-1. At higher rates, the true flow stress increases 
significantly compared with the strain rate. The 7010 aluminum alloy exhibits an increase in the 
flow stress by a typical 30% at high strain rates (900 s-1 to 3000 s-1) compared to static values. 
Results are given at the specific true strains of 0.02, 0.05 and 0.10. The influence of the strain rate 
on stress can be seen in Fig 7 [1]. 
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Fig 7: Variation of true stress compared with true strain for 7010 alloy using two different rates (experimental data). 
For the test performed with a strain rate of 900 s-1, the flow stress reaches 850 MPa at a 0.25 
strain. 
 
Table 2: True stress at specific strains using both strain rates (experimental data). 
 Strain rate: 80 s-1 Strain rate: 900 s-1 
True strain 0.02 0.05 0.1 0.02 0.05 0.1 0.25 
True stress (MPa) 550 600 610 625 775 800 850 
 
Johnson-Cook Model 
Figure 8 shows the variation of true stress in time in relation to the wave propagation along the 
bars. Stresses are evaluated on the input bar, the object and the output bar. 
 
Fig 8: Stress measurement localizations. 
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Fig 9: Stress waves in the input bar, the output bar and the object (imposed velocities = 5.8 ms-1 ). 
The stress-time curve shows the incident, reflected and transmitted signals. 
 
Fig 10: Diagram of SHPB showing the motion in time of the tensile pulse. 
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Fig 11: von Mises stress wave propagation along bars (imposed velocities = 5.8 ms-1 ). 
The speed of wave, C along the bars is calculated using the relation: 
 
C = 5189 ms-1 
Where, E is the Young’s modulus and is the density of the bars. 
The time step element is controlled by the smallest element located in the object. It is set at 5x10-5 
ms. The stress wave thus reaches the object in 0.77 ms and travels 0.26 mm along the bar for each 
time step. Obviously, it remains lower than the element length of the smallest dimension (0.88 
mm). 
An imposed velocity of 5.8 ms-1 produces a strain rate in the object of approximately 900 s-1, while 
a strain rate of approximately 80 s-1 is achieved using an imposed velocity of 1.7 ms-1. A simulation 
is performed for each velocity value. It should be noted that the study on low rates is more limited 
in time than on high rates due to the reflected wave generated on top of the output bar. 
Figure 12 shows the true stress and true strain as a function of the strain rate. 
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Fig 12: Variation of true stress with true strain for high and medium strain rates. 
At a high strain rate (900/s), an increase in the flow stress is observed, being approximately 30% 
higher than the stress obtained for a low strain rate (80/s). The Johnson-Cook model used provides 
precise results compared with the experimental data. 
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Fig 13: Stress Z and plastic strain on object at 0.6 ms. 
The true stresses determined from both methodologies are shown side-by-side. This validates the 
analysis based on a transmitted wave. Typical curves for a model having imposed velocities equal to 
5.8 ms-1 are shown below: 
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True stress comparison in the object 
 
True strain rate in the object 
(using both computations) 
 
 
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Either data sources used to evaluate the strain rate give similar results. 
The following results show: 
 the strain rate effect on stress, with or without the cut-off frequency for smoothing (100 kHz); 
 the influence of the strain rate coefficient (comparison with experimental data). 
 
Strain rate effect 
 
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Influence of the strain rate coefficient c 
 
These studies are performed for the high strain rate model ( = 900 s-1). 
Figure 14 compares the distribution of the von Mises stress on the object, with and without the 
strain rate filtering at time t=0.6 ms. 
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Fig 14: Comparison of the distribution of the von Mises stress at time t=0.6 ms. 
More physical flow stress distribution is obtained using filtering. Explicit is an element-by-element 
method, while the local treatment of temporal oscillations puts spatial oscillations into the mesh. 
Reference 
[1] CRAHVI, G4RD-CT-2000-00395, D.1.1.1, Material Tests – Tensile properties of Aluminum Alloys 
7010T7651 and AU4G Over a Range of Strain Rates. 
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Example 9 - Billiards (pool) 
 
 
Summary 
 
 
The impact and rebound between balls on a small billiard table is studied. This example deals with 
the problem of defining interfaces and transmitting momentum between the balls. The study is 
divided into three parts: 
At first, a general study is used to see the results of a cue ball when coming into contact with the 15 
other balls arranged in a triangle. The balls are meshed for the purpose using 16-node shell 
elements (for the curvature) and a type 16 interface between each ballas well as between the balls 
and the table. The results show that the momentum is not homogenously transmitted: the balls on 
the table are not being evenly spread out. 
Secondly, the collision between two balls is studied. All parameters are the same as in the first part. 
The reaction of those two balls is then compared to the analytical results. 
Finally, six different interfaces are compared: types 16 and 17 tied or sliding interfaces using the 
Lagrange Multipliers method and a type 7 tied or sliding interface using the Lagrange Multipliers or 
the Penalty method. The study is also initiated using a quasi-static gravity application prior to 
dynamic behavior. When comparing the kinetic energy transmission, the results show that 
interfaces without the tied option provide better results than the others, and that the type 16 
interface seems to be the best. 
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9.1 - Billiards (Pool) 
 
Title 
Billiards (Pool) 
 
Number 
9.1 
Brief Description 
A pool game is modeled to show the transmission of momentum between one impacting ball and 15 
impacted balls. 
Keywords 
 16-node thick shell and sphere mesh 
 Type 7 interface using the Lagrange Multipliers method and the Penalty method 
 Type 16 sliding and tied interface, and quadratic surface contact 
 Elastic shock 
 Momentum transmission and shock wave 
RADIOSS Options 
 Type 7 interface (/INTER/TYPE7) and type 16 (/INTER/LAGMUL/TYPE16) 
 Initial velocities (/INIVEL) 
 16-node thick shell property type 20 (/PROP/TSHELL) 
Input File 
Billiard_game/Interface_16: 
<install_directory>/demos/hwsolvers/radioss/09_Billiards/Billiards_model/BILLARD* 
<install_directory>/demos/hwsolvers/radioss/09_Billiards/Billiards_model/Supplement_
Interface7Lag/BILLARD* 
Technical / Theoretical Level 
Advanced 
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Overview 
 
 
Aim of the Problem 
The purpose of this example is to investigate the transmission of momentum between several balls. 
Contact with the various interfaces using the Penalty and Lagrange Multipliers’ method is analyzed. 
Physical Problem Description 
Pool is a game consisting of 16 balls, each 50.8 mm in diameter. It is played on a small billiard 
table measuring 1800 mm x 900 mm. Fifteen (15) balls are placed in a triangle to enable their tight 
grouping. The initial velocity of the shooting (cue) ball is presumed equal to 1.5 ms-1. Elastic 
rebounds are observed. 
 
Fig 1: Pool game. 
Units: mm, g, N, MPa. 
The material is subjected to a linear elastic law (/MAT/LAW1) with the following properties: 
 
Balls: 
phenolic resin 
Frame: 
polymer 
Plate: 
slate 
Initial density 0.00137 g.mm-3 0.001 g.mm-3 0.0028 g.mm-3 
Young's modulus 10500 MPa 1000 MPa 62000 MPa 
Poisson ratio 0.3 0.49 0 
 
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Analysis, Assumptions and Modeling Description 
 
 
Modeling Methodology 
The balls are meshed with 16–node solid shells (quadratic elements) in order to improve the 
conditions of contact by taking into account the curvatures. The frame of the table is made of 16–
node solid shells to comply with the interface used. The plate is modeled using only one solid 
element. The 16–node thick shells are considered as solid elements. They are defined by a thick 
type 20 shell property (number 16 solid formulation for quadratic 16-node thick shells, fully-
integrated with 2x2x2 integration points). 
 
Fig 2: Pool game mesh. 
 
Fig 3: Mesh for balls. 
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Fig 4: 16-node thick shell element. 
The type 16 interface with the Lagrange Multipliers method is used to model the ball/ball and 
balls/table contacts. An interface must be defined for each ball (that is: 16 interfaces in total). An 
additional interface is used to define the contacts between the balls and the table (plate and frame). 
 
Fig 5: Type 16 interface: slave SHEL16 for balls and master SHEL16 for the table. 
 
Fig 6: Example of the type 16 interface defined for the contact between balls. 
Slave nodes (red) are extracted from the external surfaces of the parts. 
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RADIOSS Options Used 
An initial velocity of 1.5 ms-1 in X direction is applied to all nodes of the white (cue) ball. 
 
Fig 7: Initial translational velocities of the impacting ball. 
All nodes of the lower face of the table are completely fixed (translations and rotations). 
Gravity is considered for all the balls nodes. A function defines the gravity acceleration in the Z 
direction compared with time. Gravity is activated using /GRAV. 
 
Fig 8: Gravity function (-0.00981 mm.ms-2 ) 
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Simulation Results and Conclusions 
 
 
Curves and Animations 
 
Due to the faceting of the ball, contact between the impacting ball and the impacted balls is not 
perfectly symmetrical and momentum is not homogeneously transmitted among the balls. An 
apparent physical strike thus results. 
 
Fig 9: Collision of the balls 
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Fig 10: History of the balls’ motions (contact control: type 16 interface). 
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9.2 - Collision between Two Balls 
Study on Trajectories 
 
 
Title 
Collision between two 
balls 
 
Number 
9.2 
Input File 
Collision study: 
<install_directory>/demos/hwsolvers/radioss/09_Billiards/Collision_simulation/ 
COLLISION* 
 
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Overview 
 
 
Two balls are now considered in order to study the behavior of impacting spherical balls. 
The balls’ behavior is described using the parameters (angles and velocities) shown in Fig 11. The 
numerical results are compared with the analytical solution, assuming a perfect elastic rebound 
(coefficient of restitution is equal to 1). 
 
Fig 11: Problem data. 
Initial values: V1 = 0.7m.s
-1; V2 = 1m.s
-1; 1 = 40°; 2 = 30; massball = 44.514g. 
Modeling Methodology 
The balls and the table have the same properties, previously defined for a pool game. The 
dimensions of the table are 900 mm x 450 mm x 25 mm and the balls’ diameter is 50.8 mm. The 
balls and the table are meshed with 16-node thick shell elements for using the type 16 Lagrangian 
interface. 
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Fig 12: Mesh of the problem (16-node thick shells). 
The initial translational velocities are applied to the balls in the /INIV Engine option. Velocities are 
projected on the X and Y axes. 
 
Fig 13: Initial velocities applied on the balls (initial position). 
Gravity is considered for the balls (0.00981 mm.ms-2 ). 
The ball/ball and balls/table contact is modeled using the type 16 interface (slave nodes/master 16-
node thick shells contact). The interface defining the ball/ball contact is shown in Fig 14. 
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Fig 14: Master and slave sides for the type 16 Lagrangian interface. 
Analytical Solution 
Take two balls, 1 and 2 from masses m1 and m2, moving in the same plane and approaching each 
other on a collision course using velocities V1 and V2, as shown in Fig 15. 
 
Fig 15: General problem of collision between two balls. 
Velocities are projected onto the local axes n and t. To obtain the velocities and their direction afterimpact, the momentum conservation law is recorded for the two balls: 
 
or 
 
The shock is presumed elastic and without friction. Maintaining the translational kinetic energy is 
respected as there is no rotational energy: 
 
Such equality implies that the recovering capacity of the two balls corresponds to their tendency to 
deform. 
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This condition equals one of the elastic impacts, with no energy loss. Maintaining the system’s 
energy gives: 
 
This relation means that the normal component of the relative velocity changes into its opposite 
during the elastic shock (coefficient of restitution value e is equal to the unit). 
The following equations must be checked for normal components: 
 
The equations system using V’1 and V’2 as unknowns is easily solved: 
 
It should be noted that these relations depend upon the masses ratio. 
As the balls do not suffer from velocity change in the t-direction, maintaining the tangential 
component of each sphere’s velocity provides: 
 
The norms of velocities after shock result from the following relations. 
 
 
In this example, balls have the same mass: m1 = m2. 
Therefore: 
 and 
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The norms of the velocities are given using the following relations, depending on the initial 
velocities and angles. Used to determine the analytical solutions (angles and velocities after 
collision): 
 
 
 
By recording the projection of the velocities, directions after shock can be evaluated using relation. 
Used to determine the analytical solutions (angles and velocities after collision): 
 
 
 
 
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Simulation Results: Comparison of Numerical Results with the Analytical 
Solution 
 
 
The following diagram shows the trajectories of the balls’ center point obtained using numerical 
simulation before and after collision. 
 
Fig 16: Trajectories of balls (center of gravity). 
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Fig 17: Variation of velocities (collision at 40 ms). 
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Fig 18: Energy assessment. 
For given initial values of V1, V2, 1 and 2, simulation results are reported in Table 1. 
Table 1: Comparison of results for after collision 
Numerical Results Analytical Solution 
1’ 42.27° 1’ 44.72° 
2’ 26.75° 2’ 26.48° 
V1’ 0.731 m/s V1’ 0.731 m/s 
V2’ 0.969 m/s V2’ 0.977 m/s 
 
 
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Conclusion 
 
 
The simulation corroborates with the analytical solution. The 16-node thick shells are fully-
integrated elements without hourglass energy. This modeling provides a good transmission of 
momentum. However, the type 16 interface does not take into account the quadratic surface on the 
slave side (ball 2), due to the node to thick shell contact. Accurate results are obtained for a 
collision without penetrating the quadratic surface of the slave side in order to confirm impact 
between the spherical bodies. 
A fine mesh could improve the results. 
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9.3 - Study on Interfaces 
Comparison of Results Obtained using Different Interfaces 
 
 
Title 
Study on interfaces 
 
Number 
9.3 
Input File 
Inter_7_Penalty: 
<install_directory>/demos/hwsolvers/radioss/09_Billiards/Contact_modelling/ 
Inter_7_Penalty/TEST7P* 
Inter_7_Lagrangian: 
<install_directory>/demos/hwsolvers/radioss/09_Billiards/Contact_modelling/ 
Inter_7_Lagrangian/TEST7L* 
Inter_16_tied: 
<install_directory>/demos/hwsolvers/radioss/09_Billiards/Contact_modelling/ 
Inter_16_tied/TEST16T* 
Inter_16_sliding: 
<install_directory>/demos/hwsolvers/radioss/09_Billiards/Contact_modelling/ 
Inter_16_sliding/TEST16S* 
Inter_17_tied: 
<install_directory>/demos/hwsolvers/radioss/09_Billiards/Contact_modelling/ 
Inter_17_tied/TEST17ST* 
Inter_17_sliding: 
<install_directory>/demos/hwsolvers/radioss/09_Billiards/Contact_modelling/ 
Inter_17_sliding/TEST17S* 
Overview 
 
 
The balls and the table have the same properties as previously defined. The dimensions of the table 
are 900 mm x 450 mm x 25 mm and the balls’ diameter is 50.8 mm. 
Six interfaces are used to model the contacts (ball/ball and balls/table): 
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Table 2: Interfaces used in the problems. 
Type 16 (Lagrange Multipliers) tied or sliding: 
slave nodes/master solids contact 
Type 17 (Lagrange Multipliers) tied or sliding: 
slave 16-node shells/master 16-node shells contact 
Type 7 (Lagrange Multipliers): 
slave nodes/master surface contact 
Type 7 (Penalty) sliding: 
slave nodes/master surface contact 
The type 16 interface defines contact between a group of nodes (slaves) and a curved surface of 
quadratic elements (master part). The type 17 interface is used for modeling a surface-to-surface 
contact. For both interfaces, the Lagrange Multipliers method is used to apply the contact 
conditions; gaps are not required. Contact between the balls and the table is set as tied or sliding. 
Contact between the balls themselves is always considered as sliding. The type 7 interface enables 
the simulation of the most general contact types occurring between a master surface and a set of 
slave nodes. The Coulomb friction between surfaces is not modeled here (sliding contact) and the 
gap is fixed at 0.1 mm. The other parameters are set to default values. 
The type 7 interface with the Penalty method is not available with 16-node thick shell elements. 
Thus, brick elements replace the 16-nodes shells in this case (check in the input file). 
Contact modeling between balls (always sliding). 
 
Fig 19: Definition of slave and master sides for contact. 
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The symmetrical interface definition is not recommended when using the Lagrange Multipliers 
method (types 16, 17 and 7-Lag). The problem using the interface with the Penalty method uses 
two interfaces to model the symmetrical impact. 
 
Fig 20: Symmetrical configuration of the type 7 interface using the Penalty method 
Interface Slave (red) and Master (blue) Objects 
Type 16 – tied 
Slave: nodes 
Master: solids (16-node shell) 
Type 16 – sliding 
Slave: nodes 
Master: solids (16-node shell) 
Type 17 – tied 
Slave: 16-node shell 
Master: 16-node shell 
Type 17 – sliding 
Slave: 16-node shell 
Master: 16-node shell 
Type 7 – Lagrange 
Multipliers 
Slave: nodes 
Master: surface (segments) 
Type 7 – Penalty method 
Slave: nodes 
Master: surface (segments) 
 
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Contact between the balls and the table (sliding or tied depending on the problem): 
 
Fig 21: Definition of slave and master objects for balls/table contacts. 
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Interface Slave (red) and Master (blue) Objects 
Type 16 – tied 
Slave: nodes 
Master: solids (16-node shell) 
Type 16 – sliding 
Slave: nodes 
Master: solids (16-node shell) 
Type 17 – tied 
Slave: 16-node shell 
Master: 16-node shell 
Type 17 – sliding 
Slave: 16-node shell 
Master: 16-node shell 
Type 7 – Lagrange 
Multipliers 
Slave: nodes 
Master: surface (segments) 
Type 7 – Penalty method 
Slave: nodes 
Master: surface (segments) 
Pre-loading: quasi-static gravity loading to reach static equilibrium. 
The explicit time integration schemestarts with nodal acceleration computation. It is efficient for 
the simulation of dynamic loadings. However, a quasi-static simulation via a dynamic resolution 
method needs to minimize the dynamic effects for converging towards static equilibrium and 
describes the pre-loading case before the dynamic analysis. Thus, the quasi-static solution of 
gravity loading on the model shows a steady state in the transient response. 
To reduce the dynamic effect, dynamic relaxation can be used (/DYREL in the Engine file). A 
diagonal damping matrix proportional to the mass matrix is introduced into the dynamic equation: 
 
 
with, being the relaxation value by default, equal to 1, and T being the period to be damped (less 
than or equal to the largest period of the system). 
Thus, a viscous stress tensor is added to the stress tensor: 
 
In an explicit code, the application of the dashpot force modifies the velocity equation: 
 without relaxation 
 
 with relaxation 
with: 
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This option is activated in the Engine file (*_0001.rad) using /DYREL (inputs: = 1 and T = 0.2). 
The dynamic problem (impact between balls) is considered in a second run managed by the second 
Engine file (*_0002.rad) with a time running from 30 ms to 130 ms. 
Simulation Results: Kinetic Energy Transmission between Balls during 
Collision 
 
 
Type 17 Interface 
 
Contact between 
quadratic surfaces 
 
Balls/table contact: tied 
Ball/ball contact: sliding 
 
Type 17 Interface 
 
Contact between 
quadratic surfaces 
 
Balls/table contact: 
sliding 
Ball/ball contact: sliding 
 
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Type 16 Interface 
 
Contact nodes/ quadratic 
surface 
 
Balls/table contact: tied 
Ball/ball contact: sliding 
 
Type 16 Interface 
Contact nodes/ quadratic 
surface 
 
Balls/table contact: 
sliding 
Ball/ball contact: sliding 
 
Type 7 Interface 
Lagrange Multipliers 
method 
 
Contact nodes/ linear 
surface 
(sliding contact) 
 
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Type 7 Interface 
Penalty method 
 
Contact nodes/ linear 
surface 
 
Balls/table contact: 
sliding 
Ball/ball contact: sliding 
 
 
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Conclusion 
 
 
 Interface 
16 Tied 
Interface 
16 Sliding 
Interface 17 
Tied 
Interface 
17 Sliding 
Interface 7 
Lagrange 
Multipliers 
Interface 7 
Penalty 
Cycles 241392 241385 241387 241385 241385 773099 
Error on 
Energy 
-30.8% -1.4% -55.5% -10.8% -1.2% -46.1% 
Rolling yes no yes no no no 
Momentum 
Transmission 
partial 
quasi-
perfect 
partial good good partial 
Quadratic 
surface 
master 
side 
master 
side 
master and 
slave sides 
master 
and slave 
sides 
no no 
A non-elastic collision appears using the type 7 interface Penalty method. After impact, each ball 
has about half of the initial velocity. The momentum transmission is partial and can be improved by 
increasing the stiffness of the interface despite the hourglass energy and degradation of the energy 
assessment. 
Error on energy is more noticeable for interfaces using the Tied option, due to taking into account 
the rolling simulation. 
This study shows the high sensitivity of the numerical algorithms for the modeling impact on elastic 
balls. Regarding the interface type, the kinematics of the problem and the transmission of 
momentum are more or less satisfactory. Type 16 interface allows good results to be obtained. 
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Example 10 - Bending 
 
Summary 
 
 
The bending of a straight cantilever beam is studied. The example used is a famous bending test for 
shell elements. The analytical solution enables the comparison with the quality of the numerical 
results. Carefully watch the influence from the shell formulation. In addition, the results for the 
different time step scale factors are compared. 
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Title 
Bending 
 
Number 
10.1 
Brief Description 
Pure bending test with different 3- and 4-nodes shell formulations. 
Keywords 
 Q4 and T3 meshes 
 QEPH, Belytshcko & Tsay, BATOZ, and DKT shells 
 Mesh, hourglass, imposed velocity, quasi-static analysis, and bending test 
RADIOSS Options 
 Imposed velocity (/IMPVEL) 
 Rigid bodies (/RBODY) 
Compared to / Validation Method 
 Analytical solution 
Input File 
BATOZ: <install_directory>/demos/hwsolvers/radioss/10_Bending/BATOZ/.../ROLLING* 
QEPH: <install_directory>/demos/hwsolvers/radioss/10_Bending/QEPH/.../ROLLING* 
BT (type1): 
<install_directory>/demos/hwsolvers/radioss/10_Bending/BT/BT_type1/.../ROLLING* 
BT (type3): 
<install_directory>/demos/hwsolvers/radioss/10_Bending/BT/BT_type3/.../ROLLING* 
BT (type4): 
<install_directory>/demos/hwsolvers/radioss/10_Bending/BT/BT_type4/.../ROLLING* 
DKT18: <install_directory>/demos/hwsolvers/radioss/10_Bending/DKT18/.../ROLLING* 
Technical / Theoretical Level 
Beginner benchmark 
 
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Overview 
 
 
Physical Problem Description 
The purpose of this example is to study a pure bending problem. A cantilever beam with an end 
moment is studied. The moment variation is modeled by introducing a constant imposed velocity on 
the free end. 
The following system is used: mm, ms, g, N, MPa 
Several kinds of element formulation are used. 
The material used follows a linear elastic law (/MAT/LAW1) and has the following characteristics: 
 Initial density: 0.01 g/mm3 
 Reference density: .01 g/mm3 
 Young modulus: 1000 MPa 
 Poisson ratio: 0 
 
Fig 1: Geometry of the problem. 
Analysis, Assumptions and Modeling Description 
 
 
Modeling Methodology 
Three beams are modeled using quadrilateral shells and one beam with T3 shells. A rigid body is 
defined at the end of each beam for applying the bending moment. 
The four models are integrated into one input file. The shell element formulations are: 
 Q4 mesh with the Belytshcko & Tsay formulation (Ishell =1, hourglass control type 1, 2, and 3) 
 Q4 mesh with the QEPH formulation (Ishell =24) 
 Q4 mesh with the QBAT formulation (Ishell =12) 
 T3 mesh with the DKT18 formulation (Ishell =12) 
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RADIOSS Options Used 
At one extremity of the beam, all DOF are blocked. A rotational velocity is imposed on the master 
node of the rigid body placed on the other side. 
This velocity follows a linear function: Y=1 
 
Fig 2: Beam meshes. 
Simulation Results and Conclusions 
 
 
Numerical Results Compared to Analytical Solutions 
As shown in Fig 1, rotation around X and displacement with regard to Y of the free end are studied. 
The analytical solution of the Timoshenko beam subjected to a tip moment reads: 
 
which yields the end moment for a complete loop rotation 2 : 
 
The following tables summarize the results obtained for the different formulations. From an 
analytical point of view, the beam deformed under pure bending must satisfy the conditions of the 
constant curvature which implies that for = 2 , the beam should form a closed ring. However, 
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depending on the finite element used, a small error can be observed, as shown in the following 
tables. This is mainly due to beam vibration during deformation as it is highly flexible. Good results 
are obtained by the QBAT, QEPH and DKT18 elements, respectively. This ismainly due to the good 
estimation of the curvature in the formulation of these elements. The BT family of under-integrated 
shell elements is less accurate. With the type 3 hourglass formulation, the model remains stable 
until = 6rad. However, the moment-rotation curves do not correspond to the expected response. 
To reduce the overall computation error, smaller explicit time steps are used by reducing the scale 
factor in /DT. The results reported in the end table show that a reduction in the time step enables to 
reduce the error accumulation, even though the divergence problems for BT elements cannot be 
avoided. 
The following parameters are chosen for drawing curves and displaying animations: 
 BATOZ QEPH BT DKT 
Scale factor 0.6 0.9 0.9 0.2 
Imposed 
velocity rot. 
0.005 
rad/ms 
0.005 
rad/ms 
0.005 
rad/ms 
0.005 
rad/ms 
 
 
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The following curves show the evolution previously shown (rotation and nodal displacement by 
moment): 
 
Fig 3: Moment versus rotation around X. 
For 
 
Fig 4: Moment versus displacement along Z. 
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Fig 5: Moment versus rotation around X. 
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BATOZ QEPH BT DKT 
Sf=0.9 Sf =0.8 Sf =0.6 Sf =0.9 Sf =0.8 
Type 1 Type 3 Type 4 Sf =0.3 Sf =0.2 Sf =0.1 
Sf =0.9 Sf =0.1 Sf =0.9 Sf =0.1 Sf =0.9 Sf =0.1 
CPU 
(normalized) 
 
# cycles 
2.18 
 
97600 
2.43 
 
109800 
3.14 
 
146400 
1.23 
 
95800 
1.34 
 
107800 
42.64 
 
59100 
7.07 
 
552600 
2.62 
 
182300 
108.60 
 
-- 
1.03 
 
59100 
7.17 
 
552600 
5.44 
 
364100 
8.21 
 
621600 
16.21 
 
1243200 
Error 
 = 2 
(%) 
0% 0% 0% 0% 0% 55.3% 99% 0% 0% 55.9% 99.9% 3.4% 28.88% 3.7% 
err =20% 
(rad) 
 
degree 
6.91 
 
 
396° 
6.89 
 
 
395° 
-- -- -- 
4.36 
 
 
250° 
4.53 
 
 
260° 
6.06 
 
 
347° 
5.98 
 
 
343° 
4.38 
 
 
251° 
4.51 
 
 
258° 
6.37 
 
 
365° 
-- -- 
 
Dz = 2п 
(mm) 
-500.5 -500.5 -500.5 -500.5 -500.5 -491.2 -525.8 -518.333 -506.0 -529.8 -433.8 -476.5 -496.5 -499.4 
Mx = 2п 
(x10
+5
kN-
mm) 
-4.04 -4.05 -4.06 -4.01 -4.01 -0.21 -0.11 -3.13 -2.38 -0.07 -0.02 -3.09 -3.02 -3.08 
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Conclusion 
 
 
A description summary of the different tests is provided below: 
 QBAT element: 
This formulation gives a 2 -revolution of the beam with no energy error. However, a 20% 
error is attained for = 384 degrees. 
The decrease of the scale factor enables obtaining better results. 
 QEPH element: 
This formulation seems to be the best one to treat the problem. It enables a 2 -revolution 
of the beam to be obtained. The error remains null until = 400 degrees. 
 BT formulation: 
This formulation does not provide satisfactory results and is not adapted to this simulation, 
whatever the anti-hourglass formulation. This is mainly due to using a flat plate formulation 
and the fact that the element is under-integrated. The type 3 hourglass formulation seems 
to be better than others. 
 For DKT formulation: 
The bending is simulated correctly. However, the element is costly and the CPU time is 
much longer. 
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Example 11 - Tensile Test 
 
 
 
Summary 
 
 
The material characterization of ductile aluminum alloy is studied. The RADIOSS material laws 2, 
27 and 36 are used to reproduce the experimental data of a traction test by simulation. The 
work-hardening, damage and rupture of the object are simulated by a finite element model. The 
parameters of the material laws are determined to fit the experimental results. The influence of 
the strain rate is also studied. A strain rate filtering method is used to reduce the effect of a 
dynamic resolution on the simulation results. 
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11.1 - Law Characterization 
 
Title 
Law characterization 
 
Number 
11.1 
Brief Description 
Elasto-plastic material law characterization using a tensile test. 
Keywords 
 Shell element 
 Johnson-Cook elasto-plastic model (/MAT/LAW2) 
 Tabulated elasto-plastic (/MAT/LAW36) 
 Elasto-plastic brittle (/MAT/LAW27) 
 Necking point, damage model, maximum stress, and failure plastic strain 
RADIOSS Options 
 Boundary conditions (/BCS) 
 Imposed velocities (/IMPVEL) 
 Material definition (/MAT) 
Compared to / Validation Method 
 Experimental results 
Input File 
Law_2_Johnson_Cook: 
<install_directory>/demos/hwsolvers/radioss/11_Tensile_test/Law_2_Johnson-
Cook/.../TENSIL2* 
Law 27_Damage: 
<install_directory>/demos/hwsolvers/radioss/11_Tensile_test/Law_27_Damage/DAMAGE* 
Law_36_Tabulated: 
<install_directory>/demos/hwsolvers/radioss/11_Tensile_test/Law_36_Tabulated/ 
TENSI36* 
Technical / Theoretical Level 
Advanced 
 
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Overview 
 
 
Aim of the Problem 
It is not always easy to characterize a material law for transient analysis using the experimental 
results of a tensile test. The purpose of this example is to introduce a method for characterizing 
the most commonly used RADIOSS material laws for modeling elasto-plastic material. The use of 
"engineering” or "true” stress-strain curves is pointed out. Damage and failure models are also 
introduced to better fit the experimental response. 
Apart from the experimental results, the modeling of the strain rate effect on stress will be 
considered at the end of this example using a sensitivity study on a set of parameters for 
Johnson-Cook’s model. 
Physical Problem Description 
Traction is applied to an object. A quarter of the object is modeled using symmetrical conditions. 
The material to be characterized is 6063 T7 Aluminum. A velocity is imposed at the left-end. 
Units: mm, ms, g, N, MPa. 
 
Fig 1: Geometry of the tensile object (One quarter of the object is modeled). 
The material undergoes isotropic elasto-plastic behavior which can be reproduced by a Johnson-
Cook model with or without damage (/MAT/LAW27 and /MAT/LAW2, respectively). The tabulated 
material law (/MAT/LAW36) is also studied. 
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Fig 2: Experimental results of the tensile test: engineering stress vs. engineering strain. 
Analysis, Assumptions and Modeling Description 
 
 
Modeling Methodology 
The average element size is about 2 mm in the mesh (Fig 3). There are 201 4-node shells and 
one 3-node shell. 
The shell properties are: 
 5 integration points (progressive plastification). 
 Belytschko elasto-plastic hourglass formulation (Ishell = 3). 
 Iterative plasticity for plane stress (Newton-Raphson method; Iplas = 1). 
 Thickness changes are taken into account in stress computation (Ithick = 1). 
 Initial thickness is uniform, equal to 1.7 mm. 
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Fig 3: Mesh of the object. 
 Node number 54 was renamed "Node 1" to be compliant with the Time History. 
For node 54, only displacements in the x-direction (variable DX) are saved. 
 
Fig 4: Sections saved for Time History. 
For both sections, the variables FN and FTX, are saved; thus the following variables will be 
available in /TH/SECTIO: FNX, FNY, FNZ (saved using "FN"), and FTX. 
Engineering strains will be obtained by dividing the displacement of node 1 with the distance up 
to the symmetry axis (75 mm). Engineering stresses will be obtained by dividing the force 
throughsection 1 with its initial surface (10.5 mm2). Therefore, the results shown correspond to 
the engineering stress as a function of the engineering strain, equivalent to the force variation 
compared to displacement (similar curve shape). 
RADIOSS Options Used 
An imposed velocity of -1.0 m/s in the x-direction is applied to the nodes, shown below (abscissa 
less than or equal to 25 mm). The displacement is proportional to time. 
 
Fig 5: Imposed velocities 
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Fig 6: Variation of node 1 x-displacement in relation to time. 
Only one quarter of the object is modeled to limit the model size and to eliminate the rigid body 
motions. Symmetry planes are defined along axis x = 100 mm and axis y = 0. Two boundary 
conditions cannot be applied to the same node 13 (corner). 
 
Fig 7: Boundary conditions 
The lower side is fixed in Y and Z translations and X, Y, and Z rotations. 
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The right side is fixed in X and Z translations and X, Y, and Z rotations; the node in the corner is 
completely fixed. 
Characterization of the Material Law 
There are two steps to characterize the material law: 
 Transform the engineering stress versus engineering strain curve into a true stress versus 
true strain curve (this step applies to any material law). 
 Extract the main parameters from the true stress versus true strain curve, to define the 
material law (Johnson-Cook law and material coefficients for /MAT/LAW2 or the yield curve 
definition for /MAT/LAW36). 
- True stress/true strain curve 
Engineering strains are computed using the following relationship: 
 
And true strains are computed with the relationship: 
 
Both strains, therefore, are linked together by: 
 
Engineering stresses are measured by dividing the force through one section with the initial 
section. True stresses are measured by dividing the force with the true deformed section: 
 
Thus, to compute true stresses, the surface variation must be taken into account. Assuming that 
Poisson’s coefficient is 0.5 during plastic deformation, the true surface in mono-axial traction is: 
 
Thus, the relationship between true and engineering stresses is: 
 
Characterization of the Material Law 
The characterization will be made for /MAT/LAW2 (Johnson-Cook elasto-plastic), /MAT/LAW27 
(elasto-plastic with damaged model) and /MAT/LAW36 (tabulated elasto-plastic). For each of the 
material laws, the yield stress and Young’s modulus are determined from the curve. 
The plastic strain can be defined as: 
 
An important point to be characterized on the curve is the necking point, where the slope of the 
force versus the displacement curve is equal to 0, and where the following relationships apply: 
 
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Fig 8: Guidelines for necking point. 
Table 1: Equations used for analysis 
Material 
Property 
Generic Equation 
Engineering stress 
 
Engineering strain 
 
True stress 
True strain 
True strain rate 
 
 
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Simulation Results and Conclusions 
 
 
Experimental Results 
An experiment designed by the "Norwegian Institute of Technology" as part of an EC-financed 
program, "Calibration of Impact Rigs for Dynamic Crash Testing" is used. The following curve was 
obtained from the experiment: 
 
Fig 9: Engineering stress versus engineering strain curve (experimental data). 
It is estimated that the necking point occurs between 6% and 8% (engineering strain). After 
analyzing the experimental data, the first point satisfying the necking condition is at 6.68%. 
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Fig 10: Comparison between engineering and true curves (from experimental data). 
Engineering formulation is converted into true formulation using the relationship: 
 
The true stress curve is higher than the engineering stress curve, as it takes into account the 
decrease in the objects cross-section. 
Law 2: Elasto-plastic Material Law using the Johnson-Cook Model 
 
 
Johnson-Cook Material Coefficients 
The stress versus plastic strain law is: (Johnson-Cook model) 
where, a is the yield stress and is read from the experimental curve and then converted into true 
stress. 
To compute b and n, two states are needed. This leads to the following formulas for b and n: 
 
The first point is chosen at the necking point, then b and n are computed for each other point of 
the curve and averaged out since the results tend to differ depending on the point chosen. 
Characterization up to the Necking Point 
The first stage when determining the material model is to obtain Johnson-Cook’s coefficients. 
Neither the maximum stress, nor the failure plastic strain effects are taken into account here (set 
at zero). 
The values of coefficients are chosen so that the model adapts to the test data. 
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Fig 11: Variation of the engineering stress/strain according to Johnson-Cook’s model adapted to the test. 
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The material coefficients used for Law 2 are: 
Initial density: 2.7x10-3 g/mm3 Yield stress: 90.27 MPa 
Poisson’s ratio: 0.33 Hardening parameter: 223.14 MPa 
Young’s modulus: 60400 MPa Hardening exponent: 0.375 
 
Figure 12 compares the yield curve defined using the Johnson-Cook model with the one extracted 
from experimental data. 
 
Fig 12: Yield curves Johnson-Cook model 1 
The true stress – true strain relationship can be described by: 
 
The engineering stress deviations between experiment and simulation are described in the table 
below: 
Engineering strain 0.01 0.02 0.03 0.04 0.05 0.06 0.067 
Deviation 7.9% 4.8% 1.8% 1.1% 1% 1.8% 2.9% 
Comparison is performed up to the necking point (engineering strain = 6.68%) because after this 
state, a rapid decrease in the engineering stresses occurs in the object. The rupture sequence is 
simulated in the following paragraphs. Results using Law 2 remain within 8% of the experimental 
curve. 
The curve could be improved by slightly adjusting some of the values. The purpose of this test is 
to propose a method for deducing material law parameters using a tensile test. 
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Beginning of the Necking Point 
 
 
Necking Point Simulation 
The Johnson-Cook model previously defined corresponds to the experimental results up to the 
necking point. However, the slope of the numerical response does not enable the necking point to 
start at the strain value observed experimentally. 
The necking point is characterized by the slope value of the true stress versus the true strain 
curve, which must be approximately equal to the true stress. The necking point numerically 
appears by continuing simulation until the condition on the slope is observed. 
The results are obtained using the Johnson-Cook model 1: 
 
 
Fig 13: Beginning of the necking point using only the first coefficients of the Johnson-Cook model (a, b and n). 
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Fig 14: True stress versus true strain curve up to the beginning of the necking point. 
The necking point can be simulated, either by adjusting the Johnson-Cook coefficients to obtain 
an accurate slope, or by compelling curve with a maximum stress. 
Simulation of the Slope near the Necking Point 
By implementing an energy approach, the hardening curve can be modified to achievean 
engineering curve which resembles a horizontal asymptote near the necking point with the 
purpose of simulating the behavior of the curve as observed in the test. 
The Johnson-Cook coefficients used to describe the physical slope are: 
Yield stress: 79 MPa 
Hardening parameter: 133 MPa 
Hardening exponent: 0.17 
For this model, the new true stress/true strain relationship is: 
 (Johnson-Cook model 2) 
The results obtained with those coefficients are provided below. 
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Figure 15 compares the Johnson-Cook model 3 with the experiment: 
 
Fig 15: Adjusted engineering stress/strain curve to model the beginning of the necking point. 
The shape of the yield curve versus the experimental data is depicted in Fig 16. 
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Fig 16: Yield curves. 
The necking point is defined as . 
This condition is characterized by the intersection of the true stress versus the true strain curve 
with its derivate. 
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Fig 17: Superposition of engineering curve and true curve with its derivate. 
Beginning of the Necking Point Using a Maximum Stress Limit, max 
For this test, the Johnson-Cook coefficients input are those set in characterization up to the 
necking point, the failure effect not being taken into account (the failure plastic strain is set to 
zero). The beginning of the necking point is set using the choice of a maximum stress value. In 
comparison to the experimental results (see Fig 10), the necking point is well defined for a 
maximum stress set at 175 MPa. The limit in stress appears on the von Mises stress versus true 
strain curve on elements where the necking point occurs. 
The maximum true stress manages the beginning of the necking, as shown below: 
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Fig 18: Engineering stress versus engineering strain; necking point characterization 
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Fig 19: Variation of the von Mises stress with the true strain from shell 11. 
Maximum stress max is reached for von Mises stress on shells where the necking begins. To 
avoid overly-high stresses after the necking point, a maximum stress factor must be set 
approximately equal to the true necking point stress. 
The following curves show the evolution of the von Mises stress versus the true strain shell at 
two characteristic locations of the object (3b and 3a in Fig 20): 
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Fig 20: von Mises stress curve with a maximum stress limit. 
The beginning of the necking point is observed following the point where the stress is equal to 
stress versus strain derivate . 
 
Fig 21: Yield curve with maximum stress. 
The yield curve is described by: 
 
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The derivate of the stress is very sensitive and strongly depends on the yield curve definition. 
Thus, introducing the necking point into the simulation is very delicate (a small change can result 
in many variations). The necking point should first begin on a given element for numerical 
reasons. The preferred beginning of necking is addressed below. 
Preferred Beginning of the Necking Point 
Experimentally, the beginning of the necking point can appear anywhere on the object. The 
beginning of the necking point should preferably be located on the right end elements in order to 
propose a methodology for this quasi-static test. If the model only uses a quarter part of the 
object, the necking point is found on elements 30, 125 and 78. 
The beginning of the necking point is physically and numerically sensitive and can be initiated on 
the right elements by changing a few of the coordinates along the Y-axis of the node in the right 
corner (node 16) in order to decrease the cross-section and privilege the necking point in this 
zone. Changing the node position by 0.01 mm is enough for achieving the preferential beginning 
of the necking point. 
 
Fig 22: Node 16 to be moved. 
A second approach also enables the necking point to be triggered on the right end side by 
defining an extra part, including shells 3, 11 and 4 by using a maximum stress slightly lower than 
the remaining part, in order to initiate the necking point locally since the necking point stress is 
first reached in the elements having the lowest maximum stress value, that is shells 3, 11 and 4. 
This method, based on material properties, is quite appropriate for demonstrating the 
characterization of a material law and will thus be used in the continuation of the example. 
 
Fig 23: Localization of the beginning of the necking point according to the models using max. 
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The material is described as Johnson-Cook model 1: 
 
max = 174 / 175 MPa 
The following curves indicate the variation of the engineering stress versus the engineering strain 
according to the beginning of the necking point zone and in comparison to the experiment. 
 
Fig 24: Engineering stress/strain curve for each starting necking point location. 
There is a fast decrease in the engineering stress after the right-end necking point. The necking 
point, due to the boundary conditions of the y-symmetry plane (y-translation DOF released), 
becomes more pronounced. 
The variations in the section where the necking point is found are quite similar up to the necking 
point. After such point, there is a sharp surface decrease for the right-end necking point, contrary 
to the second case where the surface decrease is more moderate. 
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Fig 25: Variation of cross section (necking point zone). 
Improvement of the Elements’ Contribution during the Necking Point 
Sequence 
 
 
In order to simulate physically the contribution of each element in the necking point, it is 
advisable to adjust the curve by varying the Johnson-Cook coefficients in order to increase the 
intensity of stress at the necking point. The main result is no longer the variation of the 
stress/strain curve but rather the surface under the curve which characterizes the energy 
dissipated during the test. This energy-based approach is relevant for crash tests since the final 
assessment is often more significant than how it was achieved. 
 
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Fig 26: Engineering stress/strain curve obtained using adjusted Johnson-Cook coefficients. 
The following graph compares the new yield curve with experimental data: 
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Fig 27: Yield curves. 
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Material is described in the the Johnson-Cook coefficients are: 
Johnson-Cook Model 3: 
 (true stress/strain) 
Yield stress = 50 MPa 
Hardening parameter = 350 MPa 
Hardening exponent = 0.38 
Maximum stress is set to 189 or 190 MPa (according to the parts) 
 
The results of adjustment to the Johnson-Cook coefficients are depicted below: 
 
Fig 28: Shell contribution during the necking point sequence (von Mises stress). 
As the necking point progresses, more physical results are obtained due to the new input data of 
the material law coefficients having a better element contribution. 
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Fig 29: Variation of the von Mises stress on elements 110, 109, 108, 107, 11 and 106. 
Damage Modeling with Plastic Strain Failure 
The elasto-plastic model of Johnson-Cook is used until failure, which is simulated using a plastic 
strain failure option. The element is deleted if the plastic strain reaches a user-defined value 
max. This damage model shows good stability. A maximum plastic strain is defined for each 
Johnson-Cook model: 
 
Fig 30: max = 75% ; yield curve close to experimental data: 
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Fig 31: max = 47% ; yield curve adjusted with respect to lower stresses: . 
 
Fig 32: max = 40% ; yield curve adjusted with respect to high stresses: . 
Failure is reached for relatively high true strains. 
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Law 27: Elasto-plastic Material Law with Model Damage 
 
 
Law 27 is used to simulate material damage following a Johnson-Cook plasticity law. Thus, model 
damage is associated with the previous law in order to take account of failure. 
The damage parameters are: 
 Tensile rupture strain t1: damage starts if the highest principal strain reaches this tension 
value. 
 Maximum strain m1: the element is damaged if the highest principal strain is above the 
tension value. The element is not deleted. 
 Maximum damage factors max: this value should be kept at its default value (0.999). 
 Failure strain f1: the element is deleted if the highest principal strain reaches the tension 
value. 
 
Fig 33: Stress/strain curve for damage affected material. 
The following graphs display the results obtained using the material coefficients of two previous 
Johnson-Cook models. Damage parameters complete those models.
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Damage Model A 
 
 
Damage model: t1 = 0.16 ; m1 = 0.72 ; dmax = 0.999 ; f = 1 ; max = 16 
Johnson-Cook model: 
 
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Damage Model B 
 
 
Damage model: t1 = 0.16 ; m1 = 0.45 ; dmax = 0.999 ; f = 1 ; max = 16 
Johnson-Cook model: 
 
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Law 36: Tabulated Elasto-plastic Law 
 
 
This is a tabulated law; therefore, the true stress versus plastic strain function can be directly 
used. The rupture phase can be simulated by adding points to this hardening function. 
 
Fig 34: Hardening function defined in law 36 to obtain the results below. 
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Fig 35: Results obtained with tabulated law 36. 
The hardening curve has to be defined with precision around the necking point while the decrease 
of the curve is very sensitive to its adjustment. In order to improve the modeling of the necking 
point, two points can be interpolated, one "just before" the necking point, and one "just after" 
with the slope between those two points equal to the necking point stress. 
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11.2 - Strain Rate Effect 
 
Title 
Strain rate effect 
 
Number 
11.2 
Brief Description 
The strain rate effect is taken into account, using filtering (cut-off frequency). 
Keywords 
 Shell element 
 Johnson-Cook elasto-plastic model (/MAT/LAW2) 
 Engineering strain/stress, strain rate effect, and filtering 
RADIOSS Options 
 Boundary conditions (/BCS) 
 Imposed velocities (/IMPVEL) 
Input File 
Time_History_files: 
<install_directory>/demos/hwsolvers/radioss/11_Tensile_Test/TENSILET01 
Technical / Theoretical Level 
Advanced 
Strain Rate Effect and Strain Rate Filtering (Cut-off Frequency) 
 
 
In this additional study, the Johnson-Cook model is used to study the strain rate influence on 
stress with or without filtering. There is no comparison with the experiment data in this section. 
The study of sensitivity will be performed up to the beginning of the necking point. 
 Stress-strain relationship: 
The Johnson-Cook plasticity model will take into account the strain rate effect on the elasto-
plastic material behavior in order to improve the quality of simulation. 
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The law reads as follows: 
 
where: 
 is the strain rate 
0 is the reference strain 
p is the plastic strain (true strain) 
c is the strain rate coefficient 
The two optional inputs, strain rate coefficient and reference strain rate must be defined for the 
material. The purpose of the sensitivity study is to illustrate the influence of material parameters. 
For further explanations about the Johnson-Cook model, refer to "Elasto-plasticity of Isotropic 
Materials" in the RADIOSS Theory Manual. 
Strain Rate Filtering 
Because of the numerical application of dynamic loadings, the strain rates cause high frequency 
vibrations, which are not physical; thus the stress/strain curves look "noisy". To obtain smooth 
results, the strain rate filtering option will allow the reduction of those oscillations by removing 
the high frequency vibrations. A cut-off frequency for strain rate filtering (Fcut) is used since its 
value has to be smaller than half of the sampling frequency (1/ t). 
In this example, t = 0.2163x10-3 ms. 
The constants a, b and n which define the shape of the stress/strain curve are: 
 
a = 90.27 MPa 
b = 223.14 MPa 
n = 0.375 
The results are reported in the following tables. 
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Strain Rate Effect - Plasticity Model: Johnson-Cook 
The influence of the strain rate and stress smoothing are shown below (with = 5x10-3 ms-1 and 
c = 0.1): 
Stress Comparison 
 
 
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Influence of the Cut-off Frequency for Smoothing 
 
 
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The following results show the effect of the reference strain rate, and strain rate coefficient, c: 
Influence of the Reference Strain Rate 
(c =0.1 and Fcut =10 kHz) 
 
 
Influence of the Strain Rate Coefficient, c 
(with = 10-2 ms-1) 
 
Results are smoothed with correct cut-off frequencies. 
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Figure 36 compares the distribution of the first principal strain rate in the object, with and 
without strain rate filtering. 
 
Fig 36: First principal strain rate comparison at time t=4 ms. 
A more physical strain rate distribution is achieved by filtering. Moreover, such results show 
spatial oscillations when not damped by filtering. The explicit scheme is an element-by-element 
method and the local treatment of temporal oscillations puts spatial oscillations into the model. 
 Strain rate coefficient c influence: 
If c is set to zero, the strain rate effect is not taken into account. This coefficient affects the 
yield stress and it slightly translates curves in the plastic region. It must be adjusted in 
accordance with the reference strain rate. 
 Reference strain rate influence: 
If the strain rate is lower than the reference strain rate, there is no strain rate effect. 
Therefore, the lower the reference strain rate, the more the effect will be emphasized. The 
effect appears as a translation of the curve towards higher stresses. An increase in the flow 
stress using an increasing reference strain rate is observed. 
 Cut-off frequency influence: 
The cut-off frequencymust not be set higher than half of the sampling frequency. 
Smoothing is improved as the cut-off frequency comes closer to a particular value and the 
convergence of the curve until a smoothing curve can be observed. A high-reference strain 
rate requires low cut-off frequencies. 
Conclusion 
 
 
A tensile test is simulated using several material laws in RADIOSS. A method is set up to 
correspond to the material parameters in the Johnson-Cook model. The rupture phase is very 
sensitive and the simulation results strongly depend upon the starting point for necking. The 
point-by-point definition of the hardening curve in law 36 enables to bypass the adaptation 
difficulties when using the Johnson-Cook model. However, the results following the necking point 
are very sensitive to the position of points defining the hardening curve. 
A method to filter the strain rate is also demonstrated. The method can be generalized to the 
industrial cases. 
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Example 12 - Jumping Bicycle 
 
 
Summary 
 
 
The purpose of this example is to illustrate how to use the RADIOSS description when resolving a 
demonstration example. The particularities of the example can be summarized using dynamic 
loading during a four-step scenario where a dummy is first put on a bike, then it rides on a plane 
to subsequently jump back down onto the ground. The scenario described is created using 
sensors. 
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Title 
Jumping bike 
 
Number 
12.1 
Brief Description 
After a quasi-static pre-loading using gravity, a dummy cyclist rides along a plane, then jumps down 
onto a lower plane. Sensors are used to simulate the scenario in terms of time. 
Keywords 
 Shell, brick, beam, truss, general spring, and beam 
 Sensors on rigid bodies and monitored volumes (perfect gas) 
 Quasi-static load treatment (gravity), kinetic relaxation, restart file, and MODIF file 
 Dummy and hierarchy organization 
 Type 7 interface self-impacting and rigid wall (infinite plane and parallelogram) 
 Linear elastic law (/MAT/LAW1) and Johnson-Cook law (/MAT/LAW2) 
RADIOSS Options 
 Added mass (/ADMAS) 
 Gravity (/GRAV) 
 Initial velocity (/INVEL) 
 Kinetic relaxation (/KEREL) 
 Monitored volume type gas perfect (/MONVOL/GAS) 
 Rigid body (/RBODY) 
 Rigid wall (/RWALL) 
 Sensor (/SENSOR) 
Input File 
Jumping_bicycle: <install_directory>/demos/hwsolvers/radioss/12_Bicycle/Bike/BIKERC* 
Technical / Theoretical Level 
Advanced 
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Overview 
 
 
Aim of the Problem 
The purpose of this example is to set up a demonstration in which sensors and restart files are 
used to allow the change of a problem over time. 
Physical Problem Description 
Subjected to the gravity field, a dummy cyclist rides on a higher plane, then jumps down onto a 
lower horizontal plane. The problem can be divided into four phases: 
 positioning the cyclist under the gravity effect 
 running the bicycle on the high plane 
 free fly 
 the impact on the ground 
The following system is used: mm, s, ton, N, MPa 
 
 
Fig 1: Problem scenario. 
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Analysis, Assumptions and Modeling Description 
 
 
Modeling Methodology 
The bike is meshed with 12103 4-node shells, 68 3-node shells, 62 trusses, 12 beams and six 
brick elements. The dummy consists of 4779 4-node shells, 207 3-node shell and 27 springs (8). 
 
Fig 2: Meshes of the main parts of the model. 
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The material of the metallic parts use the Johnson-Cook law (/MAT/LAW2) with the following 
properties: 
 Young’s modulus: 210000 MPa 
 Poisson’s ratio: 0.3 
 Density: 7.9x10-9 GKg/l 
 Yield stress: 185.4 MPa 
 Hardening parameter: 540 MPa 
 Hardening exponent: 0.32 
A QEPH formulation (Ishell = 24) is used for tires in order to prevent hourglass deformations. A 
Belytschko & Tsay element with a type 4 hourglass formulation is used for the other shell parts. A 
global plasticity model is used. 
Materials and proprieties are provided in the table below: 
 
Table 1: Proprieties and materials of main parts 
 Parts Properties Materials 
Bike 
Frame Shell Q4 – 3 mm Steel – Law 2 
Spokes Truss – 2 mm2 Steel – Law 2 
Rim Shell Q4 – 3 mm Steel – Law 2 
Tires Shell QEPH – 3 mm Rubber – Law 1 
Hubs Beam – 900 mm2 Steel – Law 2 
Saddle Brick Foam – Law 1 
Pedals Beam – 900 mm2 Steel – Law 2 
Tube of saddle Shell Q4 – 3 mm Steel – Law 2 
Dummy 
Body (limbs) Shell Q4 – 3 mm Law 1 
Joints Spring (8) - 
Hierarchy organization: 
 Bike model: 6 subsets comprising 23 parts 
 Dummy model: 11 subsets comprising 38 parts 
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Monitored Volumes / Perfect Gas 
A perfect gas monitored volume is defined to model the pressure in the tires. For further details 
about monitored volumes, refer to the RADIOSS Theory Manual. 
The main properties are: 
 External pressure: 0.1 MPa 
 Initial internal pressure: 0.75 MPa 
 Gas constant: 1.4 
All other properties are set to default values. 
 
Fig 3: Visualization of a monitored volume (yellow part). 
 Quasi-static loading: gravity effect on initial static equilibrium 
The quasi-static solution of gravity loading on structure deformation corresponds to the 
steady state part of the transient response. It describes the pre-loading case before the 
dynamic analysis. Therefore, the simulation is divided into two phases: quasi-static 
response (structure subjected to the gravity) and dynamic behavior (run, jump and 
landing). The solution is obtained from kinetic relaxation (see /KEREL). Gravity is defined 
by /GRAV. 
 Contacts modeling 
The type 7 interface using the penalty method serves to model contacts between the 
dummy cyclist and the bike. A self-impacting interface (symmetrical) is required to treat 
the landing of the bike. It is modeled by a type 7 interface having default values. Figure 4 
below illustrates the description of the interface. 
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Fig 4: Contacts modeling with type 7 interface (Penalty method). 
A type 11 interface models contact between the pedals (beams) and the feet (shells). 
 Links between man and bicycle 
The spring type 8 (/PROP/SPR_GENE) general spring property model the links between the 
feet/pedals and the hands/handlebar. 
 Stiffness (TX, TY and TZ): 100 kN/m 
 Mass: 1 g 
 Inertia: 0.1 kg/mm2 
A rupture criteria based on displacements is activated by the beams connecting the hands and 
handlebar in order to simulate the fall of the cyclist after landing. 
 Left hand: Z = 20 mm 
 Right hand: Z = 20 mm 
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Fig 5: Link right hand/handlebar (Type 8 springs) 
 Dummy joints 
 
Fig 6: Type 8 Springs 
The general type 8 springs, characterize a spherical hinge with a stiffness given for each DOF. 
Directions are local and attached to a moving skew frame. Two coinciding nodes define a spring. 
Limbs are linked to the springs via the slave nodes of the rigid bodies, as shown in Fig 7. 
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Fig 7: Example of connection rigid body – spring 8 – rigid body. 
 Wheel rotation 
Beam elements are used to attach the wheel to the forks. The rotational DOF is released around 
the beam axis. 
 
Fig 8: Wheel/forks junction 
RADIOSSOptions Used 
Two types of rigid walls are set up: 
 A fixed infinite plane (floor) 
 A fixed parallelogram (springboard) 
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Fig 9: Position of the rigid walls 
The characteristics of the parallelogram plane are: 2013 mm x 1200 mm. Both rigid walls are tied 
to allow the wheels to turn. 
The infinite plane is defined by the normal vector ( ) and the parallelogram by the 
coordinates of three corners (M, M1, and M2). For both rigid walls, the slave nodes are obtained 
from the tire and rim parts (displayed in green in Fig 10). 
 
Fig 10: Slave nodes definition (green) and profile view of rigid walls 
Several rigid bodies are created (/RBODY) and activated by sensors for use at the appropriate 
time and in a chronological manner (sens_ID not equal to 0). Thus, every rigid body is not active 
at the same time. The activation order is described in the paragraph dedicated to /SENSOR. 
According to their activation time, the rigid bodies are classified in groups which are indicated in 
following table. 
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Fig 11: Classification of rigid bodies (group). 
The inertias of rigid bodies are set in local skew frames for groups A, C and D. 
Rigid body activation – deactivation: 
Groups A and B: The rigid bodies are activated during pre-loading up to equilibrium then 
applied to the initial velocity start. They are activated again just before the impact of the bike on 
the inferior plane. 
During the free fly phase, both the cyclist and the bike undergo a rigid body motion. In order to 
save the computation time, the motion can be simulated by putting the whole structure into a 
global rigid body (Group D). The rigid body is deactivated just before landing. 
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Group C: Three rigid bodies include the dummy, the frame and both wheels (not including the 
tires). This configuration allows just the wheels to turn, taking into account the active tires action 
on the plane. This rigid body is activated while the bike is running on the springboard. 
Group D: This global rigid body, including all nodes of model is activated as long as the bike is in 
the free fly phase and is deactivated just before impact on the floor. 
Group E: This rigid body is activated before impact ensures the stiffness level of the lower fork. 
A 8333 mms-1 (30 km/h) initial velocity (/INIVEL) is applied to all nodes of the model (bicycle 
and cyclist) in a parallel direction to the high plane at time t = 0.004 s. This initial condition is 
defined in the Engine file “*_0002.rad" (start time: 0.004 s) which is run after the quasi-static 
equilibrium with gravity loading. 
Options in Engine file (*_0002.rad): 
/INIV/TRA/X/1 initial translational velocities in direction x 
8333 of 8333 mm/s 
1 338000 on node 1 to 338000 
 
Fig 12: Initial translational velocities of the model bike – man (30 km/h) at t = 0.004 s. 
Gravity is applied to all nodes of the model. A constant function defines the gravity acceleration 
in the Z direction versus time. Gravity is activated by /GRAV. 
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Fig 13: Gravity function (-9810 mm.s-2). 
The explicit time integration scheme starts with the nodal acceleration computation. It is efficient 
for the simulation of dynamic loadings. Nevertheless, quasi-static simulations via a dynamic 
resolution method need to minimize the dynamic effects to converge towards the static 
equilibrium. Among the methods usually employed, the kinetic relaxation method is quite 
effective and is activated in the Engine file (*_0001.rad) with /KEREL. All velocities are set to 
zero each time the kinetic energy reaches a maximum value. 
 
Fig 14: Kinetic relaxation method with /KEREL. 
Rigid bodies are activated and deactivated with sensors (/SENSOR). A sens_ID flag characterizes 
the sensors and it is required in the rigid bodies’ definition. The five types of sensors used are: 
 TIME (activated with time) 
 DIST (activated with nodal distance) 
 INTER (activated after impact on rigid wall) 
 SENSOR (activated with sensor IS1 and deactivated with sensor IS2) 
 NOT (ON as long as sensor IS1 is OFF) 
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Fig 15: Events definition for the activations and deactivations of sensors. 
At the beginning of the simulation (time=0), the rigid bodies are automatically set to ON, as long 
as the sensors are not active. Thus, in order to deactivate the rigid bodies at the first cycle, 
active sensors at time t=0 should be used. Consequently, the rigid bodies are active when the 
sensors are not active. 
Added masses and inertia, as well as the flag for the gravity center, are ignored when a rigid 
body is managed by sensors. By default, the gravity center is only computed by taking into 
account the slave nodes mass (ICoG set at 2). The master node is moved to the computed center 
of gravity where added mass and inertia are placed. In order to distribute the mass to the 
dummy over the rigid bodies, option /ADMAS is used. 
Sensors used are: 
Table 2: Sensors used for simulation 
Name Type Definition 
Rigid body’s 
group using 
senor 
S1 TIME Time 0s. - 
S2 DIST 
Distance between rear hubs and extremity 
of springboard equal to 1810 mm. 
- 
S3 DIST 
Distance between rear hubs and extremity 
of springboard equal to 345 mm. 
- 
S4 RWALL When the infinite rigid wall is impacted. - 
SEN(S2,S3) SEN Activated with S2 and deactivated with S3 - 
SEN(S3,S4) SEN Activated with S3 and deactivated with S4 - 
SEN(S2,S4) SEN Activated with S2 and deactivated with S4 Group A/B 
NOT(SEN(S2,S3)) NOT 
Deactivated with S2 and 
activated with S3 
Group C 
NOT(SEN(S3,S4)) NOT 
Deactivated with S3 and 
activated with S4 
Group D 
 
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Sensor (S4) is also used for deactivating both the beam type springs modeling links between the 
feet and pedals (Isflag set to 1). A case could be considered without this sensor to study the risks 
of automatic pedals. 
The following graphs show the active and deactivated zones of sensors and rigid bodies. 
 
Fig 16: Activation and deactivation of sensors and rigid bodies. 
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Simulation Results and Conclusions 
 
 
The elements included in a rigid body are deactivated. Therefore, the element flags saved in 
/TH/RBODY provide information on the activation and deactivation of rigid bodies during 
simulation. 
 
Fig 17: Activation and deactivation of main model parts (elements flag ON/OFF). 
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Fig 18: Distribution of the von Mises stress on the frame after quasi-static loading. 
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Fig 19: Kinetic relaxation effect on kinetic energy with /KEREL. 
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Fig 20: Simulation phases (impact at t = 4.6 s). 
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Fig 21: Configuration of a dummy cyclist during impact on the ground (shoes not attached). 
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Fig 22: Variation of von Mises Stress for a shell element of the frame. 
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Example 13 - Shock Tube 
 
Summary 
 
 
This famous experiment is interesting for observing the shock-wave propagation. Moreover, this 
case uses the representation of perfect gas and compares the different formulations: The ALE 
uses Lagrangian or Eulerian and Smooth Particle Hydrodynamics (SPH). 
The first part of the study deals with the modeling description of perfect gas with the 
hydrodynamic viscous fluid law 6. The purpose is to test the different formulations: 
 Lagrangian (mesh points coincident to material points) 
 Eulerian (mesh points fixed) 
For the Eulerian formulation, different scale factors on time step are also tested. Furthermore, 
the SPH formulation is also tested; which does not use mesh, but rather particles distributed 
uniformly over the volume. 
The propagation of the gas in the tube can be studied in an analytical manner. The gas is 
separated into different parts characterizing the expansion wave, the shock front and the contact 
surface. The simulation results are compared with the analytical solution for velocity, density and 
pressure. 
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Title 
Shock tube 
 Number 
13.1 
Brief Description 
The transitory response of a perfect gas in a long tube separated into two parts using a 
diaphragm is studied. The problem is well-known as the Riemann problem. The numerical results 
based on the SPH method and the finite element method with the Lagrangian and Eulerian 
formulations, are compared to the analytical solution. 
Keywords 
 Brick elements 
 Lagrangian and Eulerian formulations 
 SPH modeling and hexagonal net 
 Scale factor for time step 
 Hydrodynamic viscous fluid law (/MAT/LAW6) and perfect gas modeling 
RADIOSS Options 
 ALE boundary conditions (/ALE/BCS) 
 ALE material formulation (/ALE/MAT) 
 SPH symmetry conditions (/SPHBCS) 
Compared to / Validation Method 
 Analytical solution 
Input File 
Eulerian_formulation: 
<install_directory>/demos/hwsolvers/radioss/13_Shock_tube/Eulerian_formulation/ 
TACEUL* 
Lagrangian_formulation: 
<install_directory>/demos/hwsolvers/radioss/13_Shock_tube/Lagrangian_formulation/ 
TACLAG* 
SPH_hexagonal-net: 
<install_directory>/demos/hwsolvers/radioss/13_Shock_tube/SPH_formulation/TUBSPH* 
Technical / Theoretical Level 
Advanced 
 
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Overview 
 
 
Aim of the Problem 
The shock tube problem is one of the standard problems in gas dynamics. It is a very interesting 
test since the exact solution is known and can be compared with the simulation results. The 
Smooth Particle Hydrodynamics (SPH) method, as well as the Finite Element method using the 
Eulerian and Lagrangian formulations served in the numerical models. 
Physical Problem Description 
A shock tube consists of a long tube filled with the same gas in two different physical states. The 
tube is divided into two parts, separated by a diaphragm. The initial state is defined by the values 
for density, pressure and velocity, as shown in Figures 1 and 2. All the viscous effects are 
negligible along the tube sides; it is also assumed that there is no motion in the beginning. 
 
Fig 1: Sketch of the shock tube. 
 
Fig 2: Initial states with discontinuities. 
The initial state at time t = 0 consists of two constant states 1 and 4 with p4 > p1, 4 > 1, and V1 
= V4 = 0 (table). 
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Table 1: Initial conditions in the shock tube. 
 High pressure side (4) Low pressure side (1) 
Pressure p 500000 Pa 20000 Pa 
Velocity u 0 m/s 0 m/s 
Density 5.7487 kg/mm3 0.22995 kg/mm3 
Temperature T 303 K 303 K 
Just after the membrane is removed, a compression shock runs into the low pressure region, 
while a rarefaction (decompression) wave moves into the high pressure part of the tube. 
Furthermore, a contact discontinuity usually occurs. 
Analysis, Assumptions and Modeling Description 
 
 
Perfect Gas Modeling with RADIOSS 
The hydrodynamic viscous fluid law 6 is used to describe compressed gas. 
The general equation describing pressure is: 
 
with 
where, p is the pressure, Ci are the hydrodynamic constants, En is the internal energy per initial 
volume, and is the density. 
Perfect gas is modeled by setting all coefficients C0, C1, C2 and C3 to zero. 
Also: 
C4 = C5 = - 1 
Where, is the gas constant. 
Then the initial internal energy, per initial volume is calculated from initial pressure: 
 
Under the assumption = CST = 1.4 (valid for low temperature range), the hydrodynamic 
constants C4 and C5 are equal to 0.4. 
Gas pressure is described by: 
 
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Parameters of material law 6 are provided in Table 2. 
Table 2: Material properties of gas in law 6. 
 High pressure side (4) Low pressure side (1) 
Initial volumetric energy 
density (E0) 
1.25x106 J/m3 5x104 J/m3 
C4 and C5 0.4 0.4 
Density 5.7487 kg/mm3 0.22995 kg/mm3 
 
Analytical Approach 
The shock tube problem has an analytical solution of time before the shock hits the extremity of 
the tube [1]. 
 
Fig 3: Schematic shock tube problem with pressure distribution for pre- and post-diaphragm removal. 
Evolution of the flow pattern is illustrated in Fig 3. When the diaphragm bursts, discontinuity 
between the two initial states breaks into leftward and rightward moving waves, separated by a 
contact surface. 
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Each wave pattern is composed of a contact discontinuity in the middle and a shock or a 
rarefaction wave on the left and the right sides separating the uniform state solution. The shock 
wave moves at a supersonic speed into the low pressure side. A one-dimensional problem is 
considered. 
 
Fig 4: Diagram of the shock, expansion waves and contact surface. 
There are four distinct zones marked 1, 2, 3 and 4 in Fig 4. Zone 1 is the low pressure gas which 
is not disturbed by the shock wave. Zone 2 (divided in 2 and 2' by the contact surface) contains 
the gas immediately behind the shock traveling at a constant speed. The contact surface across 
which the density and the temperature are discontinuous lies within this zone. The zone between 
the head and the tail of the expansion fan is noted as Zone 3. In this zone, the flow properties 
gradually change since the expansion process is isentropic. Zone 4 denotes the undisturbed high 
pressure gas. 
Equations in Zone 2 are obtained using the normal shock relations. Pressure and the velocity are 
constant in Zones 2 and 2’. 
The ratio of the specific heat constant of gas is fixed at 1.4. It is assumed that the value does 
not change under the temperature effect, which is valid for the low temperature range. 
The analytical solution to the Riemann problem is indicated at t=0.4 ms. A solution is given 
according to the distinct zones and continuity must be checked. Evolution in Zones 2 and 3 is 
dependent on the constant conditions of Zone 1 and 4. The analytical equations use pressure, 
velocity, density, temperature, speed of sound through gas and a specific gas constant. 
Equations in Zone 2 are obtained using normal shock relations and the gas velocity in Zone 2 is 
constant throughout. The shock wave and the surface contact speeds make it possible to define 
the position of the zone limits. 
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Zone 1 – Zone 4 
 Zone 4 Zone 1 
Pressure p p4 = 500000 Pa p1 = 20000 Pa 
Velocity u u4 = 0 m/s u1 = 0 m/s 
Density 4 = 5.7487 kg/mm
3 
1 = 0.22995 kg/mm
3 
Temperature T T4 = 303 K T1 = 303 K 
Speed of sound through gas: 
 
Specific gas constant:High pressure side (4) Low pressure side (1) 
a a4 = 348.95 m/s a1 = 348.95 m/s 
R 287.049 J/(kg.K) 
 
 
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Zone 2 
 Analytical solution Results at t = 0.4 ms 
Pressure p 
 
p2 = 80941.1 Pa 
Velocity u 
 
u2 = 399.628 m/s 
Density 2 = 2RT2 2 = 0.5786 kg/mm
3 
Temperature T 
 
T2 = 487.308 K 
Shock wave speed: 
 
Therefore, x2/1 = Vs * 0.4 + 500 = 765.266 mm 
Zone 2' 
 Analytical solution Results at t = 0.4 ms 
Pressure p p2 = p2' p2' = 80941.1 Pa 
Velocity u u2 = u2' u2' = 399.628 m/s 
Density 2' = 3(x4/3) 2' = 1.5657 kg/mm
3 
Temperature T p2' = r2'RT2' T2' = 180.096 K 
Surface contact speed: Vc - u2 
Therefore, x2/2' = 2 * 0.4 + 500 = 559.85 mm 
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Zone 3 
Zone 3 is defined as: 
 
where, x = 500 + X 
 
 
 
 Analytical solution Results at t = 0.4 ms 
Pressure p 
 
Velocity u 
 
u3 = 290.792 + 2.0833 X 
Density 
 
 
Temperature T 
 
 
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Continuity verifications: 
 
 
Finite Element Modeling with Lagrangian and Eulerian Formulations 
Gas is modeled by 200 ALE bricks with solid property type 14 (general solid). 
The model consists of regular mesh and elements, the size of which is 5 mm x 5 mm x 5 mm. 
 
Fig 5: Mesh used for Lagrangian and Eulerian approaches. 
In the Lagrangian formulation, the mesh points remain coincident with the material points and 
the elements deform with the material. Since element accuracy and time step degrade with 
element distortion, the quality of the results decreases in large deformations. 
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In the Eulerian formulation, the coordinates of the element nodes are fixed. The nodes remain 
coincident with special points. Since elements are not changed by the deformation material, no 
degradation in accuracy occurs in large deformations. 
The Lagrangian approach provides more accurate results than the Eulerian approach, due to 
taking into account the solved equations number. 
For the ALE boundary conditions (/ALE/BCS), constraints are applied on: 
 Material velocity 
 Grid velocity 
The nodes on extremities have material velocities fixed in X and Z directions. The other nodes 
have material and velocities fixed in X, Y and Z directions. 
The ALE materials have to be declared Eulerian or Lagrangian with /ALE/MAT. 
 
Smooth Particle Hydrodynamics Modeling (SPH) 
The 12798 particles are distributed though a hexagonal compact net. No mesh is used. 
 
Fig 6: Smooth Particle Hydrodynamics modeling with hexagonal compact net. 
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The nominal value h0 is the distance between each particle and its closest neighbor. According to 
the assigned property of the part, the mass of the particles should be calculated. The mass is 
related to the density and the size of the net, in accordance with the following equation: 
 
Where: 
 Particle mass of low pressure part: mp = 1.25265x10
-5 g 
 Particle mass of high pressure part: mp = 3.13166x10
-4 g 
Particle mass is specified in the SPH property set. 
The scale factor of the time step is set to 0.3 in order to ensure cell stability computation. 
Boundary conditions are used to introduce SPH symmetry conditions (/SPHBCS). This option is 
specific to the SPH modeling and consists of creating ghost particles, symmetrical to the real 
particles with respect to the symmetry plane. 
 
Fig 7: SPH symmetry planes definition. 
Each symmetry condition is defined according to the plane passing through the frame origin 
attached to the plane and is normal in relation to the local direction of this frame. 
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Selected nodes and SPH symmetry condition frame along (-x) axis: 
 
Six symmetry planes are used: 
 x and (-x) symmetry conditions: SLIDE without rebound (Ilev =0) 
 y and (-y) symmetry conditions: SLIDE without rebound (Ilev =0) 
 z and (-z) symmetry conditions: TIED with elastic rebound (Ilev =1) 
For the SLIDE-type condition, the material is perfectly sliding along the plane 
The particles must lie on the symmetry planes at t = 0. 
 
Fig 8: Local direction of frame 
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Particles should move into the positive semi-space defined as: 
 
Where, O is the origin of the frame, P is a point of the plane, and is the local direction of the 
frame. 
Simulation Results and Conclusions 
 
 
Comparison of the Finite Element Results with the Analytical Solution 
Simulation results along the tube axis at 0.4 ms are shown in the following diagrams. 
 
Pressure 
 
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Density 
 
 
Velocity 
 
 
 Lagrangian formulation: Scale factor = 0.1 
 Eulerian formulation: Scale factor = 0.5 
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Scale Factor Effect on Eulerian Results 
Case 1: Scale factor = 0.5 
Case 2: Scale factor = 0.9 
Pressure 
 
 
Density 
 
 
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Comparison of SPH Results and Analytical Solution 
Simulation results along the tube axis at 0.4 ms. Scale factor: 0.3 and 0.67. 
 
Pressure – Hexagonal Net and SPH Symmetry Conditions 
 
 
Density – Hexagonal Net and SPH Symmetry Conditions 
 
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Velocity – Hexagonal Net and SPH Symmetry Conditions 
 
 
Indications on computation for each formulation are given in the following table (the scale factor 
is set to 0.5): 
 
 Finite Element approach SPH approach 
Formulation Lagrangian Eulerian SPH 
Normalized CPU 1.08 1 1809 
Number of cycles 
(normalized) up to 0.4 
ms 
1.42 1 3.46 
(DTsca=0.5) 
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Pressure Distribution along Tube at 0.4 ms 
 
 
 
Fig 9: Pressure wave produced in the shock-tube at t = 4 ms for different approaches and animations regarding pressure, 
density and velocity 
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Reference 
[1] J. D. Anderson Jr., Modern Compressible Flow with Historical Perspective, McGraw Hill 
Professional Publishing, 2nd ed., Oct. 1989. 
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Example 14 - Truck with Flexible Body 
 
 
Summary 
 
 
This example compares different studies with flexible or rigid bodies. The method for using the 
flexible bodies in an explicit analysis is also studied. 
At first, the truck is modeled using a classical finite element model for explicit analysis. All parts 
of the truck are modeled using different kinds of finite elements, such as shells, bricks, springs 
and beams. The volumes monitored with perfect gas characterize the tires. 
The problem is divided into two loading phases. First, gravity is applied as a quasi-static load. 
Then, the truck’s Virtual Proving Ground (VPG) is studied to observe the truck driving over an 
obstacle (bump). 
For the gravity loading phase, the explicit approach using relaxation techniques or not is 
employed. For the VPG analysis, three approaches are compared: (i) classical finite element 
model; (ii) simplified finite element model with a global rigid body; and (iii) finite