Application of local stress-strain approaches in the prediction of fatigue crack initiation life for cyclically non-stabilized and non-Masing steel

This study presents a methodology of life prediction of fatigue crack initiation for the cyclically non-stabilized and non-Masing steel. The cyclic behavior of 316L stainless steel was modelled, and the constitutive model was combined with local stress-strain approximations at a notch. The local stress-strain approximation methods were formulated incrementally to get the notch tip stress-strain of the non-Masing material. The local approximations were compared with the FEM results for verification. The prediction of fatigue crack initiation life was carried out by adopting plastic strain energy density (PSED) as a fatigue parameter and all the life prediction results were within factors of two of the experimental results.