IMPROVEMENT OF THE NUMERICAL PREDICTION OF DUCTILE FAILURE WITH AN INTEGRAL NONLOCAL DAMAGE MODEL

Abstract

In this contribution, the implementation of a nonlocal formulation is described aiming to improve the reliability of the numerical prediction of ductile failure. The nonlocal model, which is based on a simplified version of Lemaitre's material model [1], is achieved by redefining the damage variable to be nonlocal using an integral formulation. The nonlocal constitutive problem is then discretised with respect to pseudo-time by means of a backward Euler scheme. A numerical approach similar to a fully implicit elastic predictor/return mapping algorithm [2] is adopted here with the difference that in the present algorithm all material points are integrated simultaneously. The results show that the proposed numerical strategy improves the numerical reliability of ductile failure prediction by attenuating the pathological dependency of numerical results upon mesh refinement.