Probabilistic fatigue life prediction of notched components using strain energy density approach

Abstract

To meet various functional requirements, engineering components are usually designed with geometrical discontinuities, which raise stress concentrations undergoing external loadings. Comparing with other locations, these regions with high levels of stress incline to initiate cracks under cyclic loadings, which determine fatigue strength of the whole part. Accordingly, a novel strain energy density-based model for notch fatigue life prediction is developed, and a P–W–Nf curve is raised to consider the fatigue life scatter originating from material dispersity. Experimental data of different notched specimens made with TC4 alloys are used for model validation and comparison. Results indicate that the proposed model predictions show higher accuracy than the other four models. Finally, fatigue life assessment of a compressor disk considering material and load uncertainties is conducted.