FULLY IMPLICIT INTEGRATION AND CONSISTENT TANGENT MODULUS IN ELASTOPLASTICITY

This paper deals with the numerical integration of a class of rate-independent elasto-plastic models. The backward Euler scheme is used to integrate the rate constitutive relations. The non-linear equations obtained are solved by the Newton method. The consistent tangent modulus is obtained by exact linearization of the algorithm. In the case of J2 elasto-plasticity with non-linear isotropic hardening and non-linear kinematic hardening (Chaboche-Marquis model), explicit formulas are derived, without any approximations.