Application of hysteresis energy criterion in a microstructure-based model for fatigue crack initiation and evolution in austenitic stainless steel

The Sistaninia-Niffenegger Fatigue (SNF) model, a mesoscale hysteresis energy-based model of fatigue crack initiation, is calibrated and validated both by experiments and numerical modeling. The simulations are able to reproduce the fatigue life curves for the AISI 316L austenitic stainless steel of different grain sizes. In addition, it's shown that the model captures the crack initiation site and the subsequent propagation through the anisotropic microstructure in a real multi-notched sample subjected to high cycle fatigue (HCF) loading. The microstructure of the polycrystal is determined by electron back scattering diffraction (EBSD), whereas the material properties of the polycrystal and the parameters of the model are obtained by inverse analysis using the Levenberg-Marquardt algorithm, based on the tensile stress-strain curves and the HCF test results, respectively. The model can be applied to different microstructures under HCF loading and evaluate crack initiation and its evolution with precision within the intrinsic scattering of HCF tests.