Learning Forum

[Peter Hagan]

Hello,

I can't seem to find a solution to my specific problem, and I am sure it is quite simple. 

I have a hollow, rectangular box modeled as shell elements and I wish to apply an external pressure to all sides of it.  I have tried displacement constraints with no success.  I suspect a potential setup issue somewhere else as well because when the simulation is solved, the entirety of the body shrinks linearly under the pressure except for the area constrained.  An example screen shot below:  The small right end face is using a displacement constraint with x, y, and z set to 0.  I know this is incorrect, but it describes the shrinking issue I am having with the model under pressure. 

I would expect the edges to bend in with stress concentrations there, but it seems to just uniformly shrink the whole unconstrained model.

Any suggestions on hot to properly constrain this model and the shrinking issue?

[Peter Hagan]

I figured out the issue.  The problem was that Discovery did not in fact keep the midsurface shell elements and made the model a solid structure.  So the pressure just uniformly shrank the whole system.  I remodeled the system in SpaceClaim and the issue has been resolved.