Mixed mode fracture analysis using extended maximum tangential strain criterion

The maximum tangential strain (MTSN) criterion is modified in this paper to predict fracture initiation in cracked specimens under mixed mode loading conditions. Theoretical investigations were performed to study the role of both first nonsingular strain term (T-strain) and Poisson's ratio on prediction of the crack propagation direction and fracture toughness. An extended version of the MTSN (EMTSN) criterion is proposed by taking into account the T-strain as well as the singular strain field. The EMTSN criterion is then examined using the experimental data reported for angled cracked plates made from polymethylmethacrylate (PMMA). It is shown that the EMTSN criterion provides more accurate estimation of the experimental results than conventional MTSN criterion. (C) 2015 Elsevier Ltd. All rights reserved.