## A numerical solution method for an infinitesimal elasto-plastic Cosserat model.

### prof Patrizio Neff

czwartek, 7 grudnia 2006, godz. 12:15, sala S-4

Abstract: We present a finite element implementation of a Cosserat elasto plastic model allowing for nonsymmetric stresses and we provide a 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 show that for vanishing Cosserat couple modulus $\mu_c\to 0$ the classical problem with symmetric stresses is approximated. Our numerical results testify to the robustness of the approximation. Notably, for positive Cosserat couple modulus there is no need for a safe load assumption. For small Cosserat couple modulus the response is numerically indistinuishable from the classical response. This is joint work with K. Chelminski, W. Mueller and C. Wieners. The paper is accepted in Math. Meth. Mod. Appl. Sci.