Étude micromécanique de l’influence de défauts sur la tenue en fatigue à grand nombre de cycles

Abstract

The aim of this study is to analyse the influence of micro-notches on the fatigue behaviour of an electrolytic copper using finite element simulations of polycrystalline aggregates. In these simulations, in which the grains are explicitly modelled, the anisotropic behavior of each FCC crystal is described by the generalized Hooke’s law with a cubic elasticity tensor and by a single crystal visco-plastic model. The numerical analysis is done using several smooth and notched microstructures. The cyclic mechanical responses of the grains are then studied for different defect sizes and the ability of three fatigue criteria to predict the defect size effect on the fatigue strength is evaluated thanks to the comparison with experimental data.