Exercise 2: Define Boundary Conditions and Loads for the Head and A-Pillar Impact Analysis

In this step, you will load the LS-DYNA user profile in HyperMesh.

1. Start HyperMesh Desktop.
2. In the User Profile dialog, set the user profile to LsDyna.

In this step, you will open the HyperMesh model file.

1. Open a model file by completing one of the following options:
   • Click File > Open > Model from the menu bar.
   • Click on the Standard toolbar.
2. In the Open Model dialog, open the head_2.hm file.
   The model appears in the graphics area.
3. Observe the model using various visual options available in HyperMesh, such as rotation and zooming.

In this step, you will create a node set, *SET_NODE_LIST, which will contain all of the nodes in the head component of the model.

1. In the Solver Browser, right-click and select Create > *SET > *SET_NODE > *SET_NODE_LIST from the context menu.

   
   
   Figure 2.

   HyperMesh creates and opens a new set in the Entity Editor.
2. For Name, enter Vel_Nodes.
3. For Entity IDs, click 0 Nodes > Nodes.

   
   
   Figure 3.

4. In the panel area, click nodes > by collector.
5. Select the head component checkbox as seen in Figure 4.

   
   
   Figure 4.

6. Click select.
7. Click proceed.

In this step, you will define the velocity for the model.

1. In the Solver Browser, right-click and select Create > *INITIAL > *INITIAL_VELOCITY from the context menu.

   
   
   Figure 5.

   HyperMesh creates and opens a new load collector in the Entity Editor.
2. Click NSID (Node Set ID), and then select Set.
3. In the Select Set dialog, select Vel_Nodes and then click OK.
4. For VX (x-component of mass center of velocity), enter 5.

   
   
   Figure 6.

In this step, you will create constraints on the ends of the pillar component of the model.

1. In the Solver Browser, right-click and select Create > *BOUNDARY > *BOUNDARY_SPC_NODE from the context menu.
   A new constraint load is created and opened in the Entity Editor.
2. Click NSID (Node Set ID) and then select nodes for SPC.

   
   
   Figure 7.

3. Verify all six DOF (degree of freedom) checkboxes are selected.
4. Verify the load type is set to *BOUNDARY_SPC.
5. Review the Constraints created on the pillar's end nodes by right-clicking and selecting Plot Loads and Vector in the context menu.

   
   
   Figure 8.

In this step, you will create a new contactsurf on the pillar element of the model.

1. In the Solver Browser, right-click and select Create > *SET > *SET_SEGMENT > *SET_SEGMENT from the context menu.
   HyperMesh creates and opens a new contactsurf in the Entity Editor.
2. For Name, enter pillar_secondary.
3. Optional: Click the Color icon, and select a color to display the contactsurf.
4. For Elements, click 0 Elements > Elements.
5. In the panel area, set the second switch to elems as seen in the following image.

   
   
   Figure 9.

6. Click elems > by collector.
7. Select the pillar checkbox as seen in the following image.

   
   
   Figure 10.

8. Click select.
9. Click add.
10. Review the contactsurf to make sure that the pyramids are pointing out of the pillar as seen in Figure 11.

    
    
    Figure 11.

11. Click return to close the panel.

In this step, you will create a contactsurf on the head component of the model.

1. In the Solver Browser, right-click and select Create > *SET > *SET_SEGMENT > *SET_SEGMENT from the context menu.
   HyperMesh creates and opens a new contactsurf in the Entity Editor.
2. For Name, enter head_master.
3. Optional: Click the Color icon, and select a color to display the contactsurf.
4. For Elements, click 0 Elements > Elements.
5. In the panel area, set the first switch to add solid faces.
6. Set the second switch to elems.
7. Click elems > by collector.
8. Select the head checkbox as seen in the following image.

   
   
   Figure 12.

9. Click select.
10. Use the nodes selector to select three nodes that belong to the same face of a solid element.
11. In the face angle field, enter 30.
12. Click add.
13. Review the contactsurf to make sure that its pyramids are pointing out of the head as seen in Figure 13.

    
    
    Figure 13.

14. Click return to close the panel.

In this step, you will create a HyperMesh group with the SurfaceToSurface card image.

1. In the Solver Browser, right-click and select Create > *CONTACT > *CONTACT_SURFACE_TO_SURFACE > *CONTACT_SURFACE_TO_SURFACE from the context menu.
   HyperMesh creates and opens a new group in the Entity Editor.
2. For Name, enter contact.

In this step, you will add the slave and master contactsurfs to the HyperMesh group.

1. In the Entity Editor, click MSID and set the entity selector to Contactsurfs.

   
   
   Figure 14.

2. Click Contactsurfs.
3. In the Select Contactsurfs dialog, select head_master and then click OK.
4. Click SSID, and set the entity selector to Contactsurfs.
5. Click Contactsurfs.
6. In the Select Contactsurfs dialog, select pillar_slave and then click OK.

In this step, you will define the automatic option for the group in HyperMesh.

In the Entity Editor, for the first Options parameter, select Automatic.

Figure 15.

In this step, you will review the main and secondary surfaces for the group.

1. Click interfaces from the Analysis page as seen in the following image.

   
   
   Figure 16.

   The Interfaces panel opens.
2. Open the add subpanel.
3. Click name=, and select contact as seen in the following image.

   
   
   Figure 17.

4. Click review.
   HyperMesh temporarily displays the main and secondary entities in blue and red, respectively.

   
   
   Figure 18.

5. Click return to close the panel.

In this step, you will save your work in HyperMesh.