Residual Stresses Effect on Fatigue Life of Rolling Contacts

Abstract

The fatigue life tests carried out on two groups of ball bearings point out the positive influence of the compressive residual stresses induced by a previous loading in the elastic-plastic domain. The values of residual stresses are numerically evaluated by employing a threedimensional strain deformation analysis model. By considering the isotropic and nonlinear kinematic hardening laws of Lemaitre-Caboche, the model accounts for the cyclic hardening phenomena. To attain the final load of each loading cycle the two bodies are brought into contact incrementally. The cyclic evaluation process of both plastic strains and residual stresses is performed until the material shakedowns. The von Mises equivalent stress is considered in Ioannides-Harris rolling contact fatigue model to obtain theoretical lives of the ball bearings groups. The theoretical analysis reveals also greater fatigue lives for the ball bearings groups with induced residual stresses than the fatigue lives of the group without induced residual stresses.