On the relationship between stress intensity factor (K) and minimum plastic zone radius (MPZR) for four point bend specimen under mixed mode loading

Abstract

Studies on crack-tip plastic zones are of fundamental importance in describing the process of failure and in formulating various fracture criteria. Minimum plastic zone radius (MPZR) theory is widely used in prediction of crack initiation angle in mixed mode fracture analysis of engineering materials. In this study, shape and size of mixed mode (I/II) crack-tip plastic zones have been estimated by finite element analysis in a four point bend specimen according to von Mises yield criteria. The results obtained are used to analyze the MPZR criterion with respect to the effective stress intensity factor (K_eff) and elastic mode mixity (M_e).

Keywords: minimum plastic zone radius, mixed mode I/II, finite element analysis, mode mixity, four point bend specimen