Mixed-mode ductile fracture initiation

Abstract

In this paper, an overview of some recent computational studies by the authors on mixed-mode ductile fracture initiation is presented. In these studies, mixed-mode ductile fracture involving Modes I and II was analyzed using the finite-element procedure within the context of plane strain, small-scale yielding conditions. The main objective of these analyses was to investigate the micro-mechanics of mixed-mode ductile fracture. To this end, the finite strain version of the Gurson constitutive model which represents the ductile failure processes of micro-void nucleation, growth and coalescence was employed. The numerical simulations were carried out in three parts. In the first, ductile fracture initiation from a notch under mixed-mode loading was analyzed. In the second, the effect of initiation of a discrete void by inclusion debonding and its interaction with a nearby notch tip was studied. In the third, porosity development due to a rectangular distribution of synthetic inclusions around the notch tip was modelled. Some important results from the above simulations are presented here and are compared with available experimental observations.