I am analyzing a bronze bellows as both a 2d cross section (axi-symmetric) and a 3d shelled revlove. both models have at same material properties and thickness (bronze, .008" thick) and both have the same deflection and internal pressure (.01" delta and 340 psi). for some unknown reason, the 3d shelled revolve has stress levels about 2x the 2d model. Not sure which is more accurate or why there is such a large difference. Any help would be greatly appreciated.
Also, is there a way to use the results of the 2d analysis for a fatigue study? Thanks in advance.