Nonsymmetric Buckling of Internally Pressurized Ellipsoidal and Torispherical Elastic-Plastic Pressure Vessel Heads

Abstract

Bifurcation buckling pressures of ellipsoidal and torispherical heads joined to a cylinder are calculated with use of the BOSOR5 computer program. Predicted behavior is found to be sensitive to prebuckling geometric nonlinearity as well as material non-linearity, the former effect increasing the critical pressure and the latter decreasing it. In one case use of flow theory leads to a prediction that no buckling will occur whereas use of deformation theory leads to the opposite conclusion. A change in the slope of the post-yield hardening rate of the material dramatically affects the prebuckling behavior.