Using symmetry planes with a mid-surface bending model

- September 19, 2019 at 12:53 am
  
  Lionsmane
  Subscriber
  
  Hi team,
  
  I'm trying to model the bending of a sheet metal snap-fit clip. To do this I'm using a mid-surface model of the clip itself. The clip is symmetrical, so it would speed up the model considerably if I could cut the entire model in half and use symmetry. However I'm having trouble setting up the symmetry plane to do this, as it runs along the "thin" edge of the mid surface. Does anyone have any tips on how to do this?
  
  Thanks,
  
  Richard
- September 19, 2019 at 1:43 am
  
  peteroznewman
  Subscriber
  
  Are you working in APDL or Workbench/Mechanical?
  
  In Mechanical, right click on the Model branch in the outline and insert a Symmetry folder, then right click on the Symmetry folder and insert a Symmetry Region and select the edge(s) at the centerplane. In the details window, you must select the Symmetry Normal to the centerplane. Note: this is not automatically set to the correct value, it defaults to X but if your normal is Z, you have to change that!
  
  Instead of using a Symmetry Region, you can have a correct symmetry condition by using two separate supports. Let's say for example that the XY plane was parallel to the centerplane and the Z axis was normal to the centerplane. Use a Z = 0 Displacement support and a Fixed Rotation support where X and Y are set to zero and Z is Free.
- September 19, 2019 at 1:57 am
  
  Lionsmane
  Subscriber
  
  Hi Peter,
  
  That's great, thanks - got it working with the first method you suggested!
  
  Richard