A NUMERICAL SOLUTION METHOD FOR AN INFINITESIMAL ELASTO-PLASTIC COSSERAT MODEL

Source abstract

We present a finite element implementation of a Cosserat elasto-plastic model and provide a rigorous numerical analysis of the introduced time-incremental algorithm. The model allows the use of standard tools from convex analysis as known from classical Prandtl–Reuss plasticity. We derive the dual stress formulation and prove that for vanishing Cosserat couple modulus μ c → 0 the classical problem is approximated. Our numerical results show the robustness of the approximation. Notably, for positive couple modulus μ c > 0 there is no need for a safe-load assumption. For small μ c the response is numerically indistinguishable from the classical response.