Effect of defect size and shape on the high-cycle fatigue behavior

This study aims to examine the effects of both material microstructure and voids on the high-cycle fatigue behavior of metals. To deal with this matter, finite element analyses of polycrystalline aggregates are carried out, for different configurations of crystalline orientations, in order to estimate the mechanical state, at the grain scale, in the vicinity of a small elliptical hole. Fatigue criteria are then applied to estimate the average fatigue limit in fully reversed tension, for different defect sizes and ellipse aspect ratios. The constitutive models and the fatigue criteria are calibrated using experimental data obtained from specimens made of 316L austenitic steel. The estimations are then compared with the experimental trends.