Extended Crystal Plasticity Finite Element Approach For Neutron Irradiated Austenitic Stainless Steels

In this work, a micromechanical crystal plasticity model, recently developed by CEA, is implemented in the finite element solver ABAQUS through a user-material subroutine UMAT to simulate the nonlinear mechanical response of post-irradiated austenitic stainless steels. The proposed model, based on dislocation dynamics inferred mechanisms and finite strain theory, is able to capture the irradiation-induced hardening followed by softening due to the formation of defect free channels on each slip plane during plastic deformation. The numerical implementation is presented and validated against previous CEA calculations of various single-and polycrystal tensile responses. Also, some preliminary results of polycrystalline simulations of non-irradiated and irradiated steels are given, showing a good ability to reproduce the tensile behavior observed at different doses.