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Symmetry not working correctly

Symmetry not working correctly

Symmetry not working correctly

(OP)
I'm getting very different results when I try to use symmetry in Ansys 12.  

I have a simple box with a force on the bottom; see picture.  

When I run FEA on the whole thing, the box bottom deflects 0.1".  
When I run it in symmetry, ansys tells me the box bottom deflects 0.4".


Setup for FEA on entire model:
4000lbs force on the bottom
Fixed support around the rim

Setup for FEA on symmetric model:
Only analyzing 1/4 of model
1000lbs force on the bottom
Fixed support around the rim
Frictionless support around cut faces.


Am I missing something?  Thanks!
 

RE: Symmetry not working correctly

(OP)
Wow I just answered my own question.  The results of the symmetry FEA are correct.  

When I matched the mesh size of the whole model to the symmetry model, the results match.

Scary that the results can be off by 600% with the default mesh size....

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