Nonlocal approach in evaluating strain localization behaviors of voided ductile materials

Abstract

Finite element analysis of the strain localization behaviors of a voided ductile material has been performed using a non-local plasticity, in which the yield strength depends on both an equivalent plastic strain measure (hardening parameter) and Laplacian equivalent. The introduction of gradient terms to the yield function was found to play an important role in simulating the strain localization behavior of the voided ductile material. The effect of the mesh size and characteristic length on the strain localization were also investigated. An FEM simulation based on the proposed non-local plasticity revealed that the load-strain curves of the voided ductile material subjected to plane strain tension converges to one curve, regardless of the mesh size. In addition, the results using non-local plasticity also showed that the dependence of the deformation behavior of the material on the mesh size was much less sensitive than with classical local plasticity and could be successfully eliminated through the introduction of a large value for the characteristic length.