COMPUTATIONAL LIMIT ANALYSIS OF ANISOTROPIC AXISYMMETRICAL SHELLS

In this paper a numerical method is suggested for the limit analysis of axisymmetric shells using Hill's 1948 yield criterion. Since von Mises' condition is a special case of Hill's 1948 criterion, the new method can be applied to both the isotropic von Mises' material and the anisotropic Hill's material. By means of finite element techniques and the kinematic theorem for limit analysis, we introduce an efficient iteration algorithm to compute the upper bound of the collapse load. Numerical results of the limit analysis of cylindrical-conical-cylindrical combined shells subjected to internal pressure are presented by means of Hill's as well as von Mises' conditions. From the present investigation, some comments are made on the design of anisotropic pressure vessels of cylindrical-conical-cylindrical combined shells.