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problem defining fixture for static analysis of cylinders

Question asked by Michael Oswald on Jul 16, 2015
Latest reply on Jul 19, 2015 by Michael Oswald

I have two hollow cylinders standing on top of each other axially.  The faces in contact with each other have a very shallow, very wide chamfer.  The bottom cylinder is sitting on the ground, and I apply a 2000# force to the top cylinder (axially downwards).  I want to see if/how much the chamfers between the cylinders deform.  I think this should be really straight-forward, but when I try to run the analysis I get an error stating that "The solver has numerical difficulties.  Model may not have adequate fixtures".

 

My only physical constraint is the floor that the bottom cylinder is sitting on.  I've tried to model this with:

  • a roller/slider fixture on the bottom face
  • a fixed geometry fixture on the bottom face
  • an advanced/flat face on the bottom face with the normal translation set to 0
  • an advanced/reference geometry on the bottom face with an axis to define the direction and the translation set to 0
  • by creating a coincident reference plane on the bottom face and setting it as a virtual wall. 

 

I get the same error for all but the fixed geometry.  For that I get incorrect results - deformation in a circular motion, mainly to the positive-x direction.   I also have the global contact set to no penetration instead of bonded, because that's how the parts really are.  But I've also done it bonded, and gotten the same error.

 

I'm sure this is just a stupid error on my part.  If anyone has any suggestions, I'd really appreciate the help.  Thanks so much.

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