Large deformation analysis of ellipsoidal head pressure vessels

Abstract

Among the most common pressure vessels, the elliptical head pressure vessel stands out to be the second best in order of preferable stress distribution at the head-cylinder junction—the best being hemispherical head. But, like others, the deformation at the head-cylinder junction of this pressure vessel is so large that the stress distribution obtained from linear shell theory is far off from reality. The nonlinear shell equations of ellipsoidal head pressure vessels are solved here using the multisegment method of integration, developed by Kalnins and Lestingi[11]. Reissner's nonlinear equations for the axisymmetric deformation of shells of revolution, after specialization for ellipsoidal shells and further necessary modification for avoiding geometrical singularity at the apex of the head are used in this analysis. It is shown that the linear theory consistently over estimates the stresses at the head-cylinder junction of ellipsoidal head pressure vessels.