On the transition from shear to tensile failure mode in multiaxial fatigue

Abstract

Depending on several factors, the failure mechanism can change with life for a particular material, from shear in Low Cycle Fatigue (LCF) to tensile in High Cycle Fatigue (HCF). Critical plane-based approaches to multiaxial fatigue have the capability of reflecting the damage mechanisms of the material and can, therefore, not only provide fatigue life estimation under different stress states, but also predict the highest damage (i.e., critical) plane orientation. While Fatemi-Socie critical plane parameter has been used extensively in the literature for many materials with shear failure mechanism, a modified form of the parameter recently proposed by Gates and Fatemi is shown to also be able to capture the failure mechanism transition from shear in LCF to tensile in HCF. The mechanisms by which this parameter accounts for the transition from shear to tensile is discussed in this work. A wide range of materials from the literature with failure mechanism change from shear in LCF to tensile in HCF are evaluated based on this parameter.