I am simulating a FSI problem of a flow in a collapsible tube. The tube is circular with a constant external pressure acting on it. The pressure inside the tube is less than the external pressure applied causing the tube to deform inwards. Deformations are suppose to be large and post-buckling effects are supposed to be captured.
The problems are:
1) When I run the structural part alone, I could get the solution to converged even though the pipe has buckled. I am not using the arc-length method nor the stabilize feature but the solution converges, is there anything wrong with this?
2) When I run the structural part alone, the net pressure acting on the solid is much higher than in the coupled solution and I could get a converged result. However when I solve it together with the fluid part, there would always be the element turning inside out error. Can someone explain to me why is that so and what would be the best way to fix this?
Thanks in advance people. Cheers.
Regards, Tan Yi Yong The University of Sheffield UK