Fatigue life prediction under mixed-mode loading using equivalent stress intensity factor models

Abstract

Damage tolerance principles are widely used to assess the structural integrity and failure of engineering components. The advances in numerical simulation techniques facilitate the prediction of fatigue life of engineering component, which is essential in damage tolerance design. For the components under mixed mode (I/II) loading, the fatigue crack growth and life is predicted by using a modified form of Paris' law along with the equivalent stress intensity factor (ΔKeq). Numerous ΔKeq models are available for correlating the equivalent stress intensity factor range and the fatigue crack growth rate. The knowledge of proper ΔKeq model is essential for the accurate fatigue life estimation. In this work, the authors numerically assess the performance of ΔKeq models in mixed mode fatigue life prediction with the help of published experimental mixed mode data.