Flange and dished head


I'm curious if anyone has played around with non-linear predictionsfor snap-through load of flange and dished heads given an externalpressure load?

My initial assumption was that the code can handle this simulation,especially a very simplified shell element symmetric case, howeverafter trying I am not sure.

I'm modeling the crown portion only with external pressure, shellelements using manually defined sym. constraints along edges,non-linear-static study, plastic material, assumed non-conservativeforce update for normal pressure, large displacement formulation,and arc-length control method.

New to GNL and I'm hoping I may be missing something that isobvious to others.

Attached are response graph of center point and displacmentprofile.

Thanks for the help,
SolidworksSimulation