Three-Dimensional Inelastic Finite Element Analysis of Laminated Composites

A three dimensional theory based on Hill's orthotropic yield criterion and the incremental flow theory of plasticity is proposed for the inelastic response prediction of laminated composites. Techniques for including nonlinear hardening of orthotropic materials via unidirectional Ramberg-Osgood coef ficients as well as temperature dependent plasticity and first and second order nonlinear thermal expansions are presented. Results confirm the importance of including such effects in composite materials.