Multiaxial fatigue life prediction for various metallic materials based on the critical plane approach

This paper summarizes an attempt to devise a simple method suitable for assessing fatigue lives of metallic materials subjected to both proportional and non-proportional loading conditions. This proposed approach consists of the maximum shear strain range, the normal strain range and the maximum normal stress on the maximum shear strain range plane. In order to correctly account for the presence of non-zero out-of-phase angles, the non-proportionality factor proposed by Chen et al. was introduce to evaluate the degree of multiaxiality. Besides, the accuracy of the proposed method in estimating fatigue lifetime in the presence of non-zero mean stresses was also investigated.