A shell finite element for large strain elastoplasticity with anisotropies—: Part II: Constitutive equations and numerical applications

An eight!node C9 shell element for _nite elastic plastic deformations with anisotropies is developed[ It combines the advantages of an isoparametric description of geometry and deformation\ the application of tensors in Cartesian components\ and a real and e}ective plane stress description with three displacement and three director degrees!of!freedom at each node[ In Part I of the paper the shell theory including the kinematics\ the variational principle\ the application of Lagrange multipliers with their condensation on the element level and a comparative study of various assumed strain techniques were presented and the results of convergence tests given[ In this paper\ we consider the constitutive equations for large elastic and large plastic strains accounting for initial and induced anisotropies and the corresponding thermodynamics[ Then we investigate the return algorithm for _nite strains and the implementation of the element procedure including sti}ness matrix and residual force vector[ Finally\ we present the results of extended numerical applications and a comparison with FE solutions published in the literature\ as far as such are available