A global plasticity formulation combined with a semi-analytical analysis of imperfect shells of revolution

A semi-analytical analysis of elastic plastic imperfect shells of revolution is presented. The Kirchhoff-Love hypothesis and moderate rotations of the normal are assumed. Inextensible imperfections are introduced as strain-free initial normal displacements. The material is assumed to be elastic-perfectly plastic. The small strain flow rule is associated with the Huber-Mises-Hencky yield condition approximated for generalized stresses. The Ivanov approximation, together with Crisfield's modification, is employed. The return mapping algorithm is used when integrating the physical relationships. Expansion of variables into truncated Fourier series with respect to the circumferential variable is used to reduce the problem to a one-dimensional one. Both plane-symmetric and plane-asymmetric terms are retained. The finite difference method based on a scheme with a middle point is applied for discretization.