Manage Penetrations/Intersections

Check components or groups for element penetrations and intersections using the Penetration Check tool.

1. From the menu bar, click Tools > Penetration Check.
   Restriction: Only available in the Radioss and LS-DYNA user profiles.
   The Penetrations browser opens.
2. Setup the Penetration Check and check for intersections/penetrations.
   1. In the Penetrations browser, click to invoke the collision setup widget.
   2. In the Check type field, select the type of collision to check.
   3. In the Entity type field, select the type of entity to be checked for intersections and/or penetrations.
   4. In the Selection field, select contacts (groups) or components to check.
      Selecting one of more contacts will perform the penetration check according to the rules enforced by the solver. In any case, the penetrating elements will be found, and the results will display in the Penetration Browser. Results will be listed by pairs of components regardless of the entity type that was used to select penetration candidates.
   5. Select a Thickness option.
      Restriction: Only available for Component checks.
      • Choose Component thickness to apply no adjustments as it uses the thickness value specified in a component’s property card for each element within that component.
      • Choose Thickness multiplier to multiply the selected entities' thickness by the value entered in the Thickness multiplier field for purposes of the penetration check. Fractional values are acceptable, but negative values are not.
      • Choose Uniform thickness to ignore the existing component's thickness, and instead uses the value entered in the Uniform Thickness field for all of the components in the model.
        Note: Use Uniform thickness as a workaround to the lack of thickness information in the default HyperMesh user profile, or when working with models that do not have a thickness specified.
   6. Select a Thickness > size option.
      Restriction: Only available for Component checks.

      • Full thickness, but ignore neighborhood (slow, but accurate if thickness > element size)
      • Reduce thickness to 40% of elem size (fast)
      • Full thickness, consider neighborhood (special usage only)
   7. To consider edge penetrations, select the Consider edge penetrations checkbox.
   8. Select a treatment algorithm for the boundary shell edge.
      • Choose Flat edges to consider external borders of the components flat.

        
        
        Figure 1. Flat Edges

      • Choose Rounded edges to extend external borders of the component by a cylinder having the diameter of the component thickness.

        
        
        Figure 2. Rounded Edges

   9. Click Check.
      Once the check is complete, the browser populates with detected intersections and/or penetrations.

      
      
      Figure 3.

3. Review the penetrations/intersections using the view controls in the browser.

   
   
   Figure 4.

4. Fix the penetrations/intersections.

   To fix	Do this
   Manually	Select groups/components to fix in the browser. Click on the collision toolbar. Additional tools display. Figure 5. Select the elements or nodes to move. Move and/or translate the selected elements/nodes. Click to recheck that the intersection/penetration no longer remains.
   Automatically	Select groups/components to fix in the browser. Click on the collision toolbar.

   Tip:

   • If a component is intersecting with another, right-click on the component and select Find Matching Penetrating Component Pair from the context menu to find the same pair of components in the penetrations list. If the pair does not penetrate, a message will display.
   • To keep a specific component from changing when performing de-penetration fixes, right-click on that component and select Lock Component from the context menu. A red padlock displays on the component name in the browser to indicate that it has been locked. The nodes in a locked component cannot be moved by the Collision tool. To unlock, right-click a locked component and select Unlock Component from the context menu.

     
     
     Figure 6.

   • Sort the columns in the browser by clicking the column headings. For example, clicking the Violations heading sorts the parent components according to their number of violations. A small triangular arrow in the column heading indicates whether the components are sorted in ascending or descending order; repeated clicks toggle between these two options.