Exercise 5.2 – Hyperelastic Bushing with HyperMesh
Objectives
1. Become familiar with Hyperelastic material law
2. Understand how to set up sequential loading
This exercise demonstrates how to simulate a rubber bushing 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 – 1.50] in steps of 0.05 ms for each load case
• The outer circumference area is fixed on all translational degrees of freedom
(T X , T Y , T Z ) and the center node is fixed on X translation and the X and Y rotation (T X , R X , R Y )
• The bushing dimensions are: Thickness = 100 mm, External Diameter = 200
mm and Internal Diameter = 50 mm.
• Hyper-Elastic Material /MAT/LAW42 (Rubber)
•
= 6.0-6 Kg/mm 3  •  = 0.495
[Rho_I] Initial density [nu] Poisson’s ratio
• 1 = 0.6 GPa • 1 = 2
• 2 = -2 [mue1] [alpha1] (alpha2]
Step 1:  Load the RADIOSS (BLOCK) user profile
1. Launch HyperMesh.
2. From the Preferences menu, select the User Profiles or click on the icon in
tool bar .
3. Select RADIOSS (BLOCK) 130 and click OK.
Step 2:  Load the GASKET_0000.rad file
1. From the toolbar, click the Import Solver Deck icon  and browse to
select GASKET_0000.rad file. Click Import.
The model loads into the graphics area.
Step 3:  Define and assign material, property to Rubber
1. From the Model Browser, right mouse click and create.
3. Click on the Material tab to create material.
4. For Name, enter bushing.
5. For Card image, select M42_OGDEN and click yes on the confirmation window
6. Input the values, as shown below.
Density = 6.0e-6editor bar
Mue1 = 0.6
alpha1 = 2
alpha2 = -2
Poisson’s ratio(Nu) = 0.495
7. Similarly right mouse click in model browser to create property.
8. For Name, enter bushing
9. For Card image, select P14_SOLID and click yes on the confirmation window
10. Enter Property values as shown below for ISOLID, Ismstr and I_HKT
11.Highlight the Component bushing, right mouse click and assign the newly
created property and material in the EE .
Step 4:  Create a rigid body at center of Bushing
1. Go to 1D  page, select the rigids  panel.
2. For nodes 2-n , switch to multiple nodes .
3. for primary node , switch to calculate node .
4. Click on the nodes  and pick a node in the inner face.
5. Click on the nodes  and pick by face , HM will pick all nodes on the inner face
6. Click create .
7. Click return
to exit the panel.
Step 5: Create bushing inner fixed boundary conditions
1. From the Utility  page, start the BC’s 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.  Click Proceed
4. Check the Tx  translational and Rx , Ry  rotational degrees of freedom.
5. Click Create  (bottom of panel) to create the inner fixed boundary condition.
Step 6:  Create bushing inner Y displacement boundary conditions
1. From the Utility  page, start the BC’s Manager .
2. For Name , enter DISP_Y, set Select type  to Imposed displacement  and set
the GRNOD  to Nodes
.