A revised failure criterion for brittle elastic materials under mixed-mode loading in 2-D

We revise the failure criterion by Yosibash, Priel and Leguillon for V-notched 2-D domains made of brittle elastic materials (Yosibash et al., 2006) under mixed-mode loading. It is based on a finite fracture mechanics (FFM) concept that requires the determination of a finite virtual crack that simultaneously satisfies the normal stress criterion and the energy release rate (ERR) criterion. The FFM ERR criterion is extended to include mode II toughness (G_IIc) and reduces to the classical fracture mechanics failure criterion under constrained mode II at the limit when the V-notch solid angle approaches 2π. The revised criterion predictions of failure load and failure initiation angle are compared to experimental observations on PMMA V-notched specimens under mixed mode loading. The predictions compared to the original criterion are slightly improved, especially as the mode mixity ratio increases.