Mixed mode fatigue crack growth studies of crack emanating from circular hole

Abstract

Damage tolerance philosophy and the safe life design requires prediction of accurate fatigue crack growth life. The advent of numerical simulation and the evolution of fracture mechanics based approach for the fatigue life prediction enables the accurate fatigue prediction. Considering the mixed mode stress field around the crack tip, the modified form of the Paris law are widely employed in the fatigue life prediction. In modified Paris' law contains the equivalent stress intensity factor, and researchers proposed various models for correlating the individual mode stress intensity factors to equivalent stress intensity factor. The selection of a proper model for the estimation of fatigue life has a significant impact on the predicted fatigue life. In this work, the fatigue life is predicted using seven different equivalent stress intensity factor models available in the literature and the similitude in their prediction is assessed analogous to published experimental results. In the present study, a plate with crack emanating from the circular hole is considered. Various error estimation techniques are presented to provide conclusive information about the efficacy of the selected models.