A FORMULATION OF THE MITC4 SHELL ELEMENT FOR FINITE STRAIN ELASTOPLASTIC ANALYSIS

A finite strain elasto-plastic formulation is developed for the MITC4 shell element. The developed formulation is based on Lee's multiplicative decomposition of the deformation gradient and on the hyperelastic expression of Von Mises flow rule expressed in terms of Hencky's strain tenser. The formulation incorporates thickness stretching degrees of freedom that are condensed at the element level by imposing the classical 'in-layer' plane stress condition. A symmetric and consistent tangent stiffness matrix is also developed.