Numerical Simulation of Fatigue Surface Crack Propagation under In-plane Biaxial Cyclic Loading with Different Phases

Abstract

Most of in-service structures are subjected to many types of cyclic loading and these cyclic loadings have different axial components with different phase. In-addition, most of the fatigue cracks occurring in the structures are so-called surface cracks which can be approximate elliptical shape. However, the fatigue strength of structures is evaluated according to design standards established by theoretical and experimental investigations under uniaxial cyclic loading condition. On the other hand, authors proposed the numerical simulation procedure of through thickness fatigue crack propagation histories of a cracked plate subjected in-plane biaxial loadings with phase differences of each loading component from a viewpoint of fracture mechanics approach. In this study, fatigue surface crack growth behavior under in-plane biaxial loading with different phase conditions are investigated. The phase difference effect for fatigue surface crack shape evolution under in-plane biaxial loading is confirmed by measured ones. Besides, the numerical simulation method of fatigue crack growth is proposed and confirmed this method by comparisons of measured crack evolution with the numerical simulation.