Numerical analysis of thin torispherical end closures

Abstract

A numerical analysis study using the finite element method has been carried out to investigate the design sensitivity of thin torispherical end pressure vessels. A detailed dimensional survey of a number of thin full-size production-quality torispherical ends has shown that actual dimensions may differ significantly from nominal dimensions. The sensitivity of the end stresses to particular forms of shape imperfections were analysed numerically and compared with those in the corresponding ‘perfect’ end which are presented here in more detail. The effect of these shape imperfections on buckling pressure is also investigated. The buckling pressure and stresses in a series of torispherical ends are evaluated to show the effect of variation of shape parameters in these ends. It is also shown that, for stainless steel ends, small displacement analysis agrees much better with the experimental results than do those given by the large displacement analysis.