A review of in-plane biaxial fatigue behavior of metallic materials

Aerospace components, such as aircraft fuselage panels, pressurized container and turbine blades are exposed to in-plane biaxial fatigue loading in service. Assessment of the effect of biaxial stress state is of great importance in structural reliability analysis. In this paper, the current state of understanding and development of the fatigue behavior of metallic materials under in-plane biaxial loading is reviewed. The fatigue properties in cruciform specimens were examined under in-phase and out-of-phase biaxial loading as well as in-phase biaxial loading with overloads. The effect of stress biaxiality on the fatigue behavior, including crack initiation, crack trajectory, crack growth rate and fatigue life, were presented. The fracture morphology analysis was shown to clarify the mechanism of biaxial fatigue damage. Furthermore, several models that have been used to predict the biaxial fatigue behavior were analyzed. The applicability of these models in correlating biaxial experimental data were evaluated.