Effect of initial surface treatment on shot peening residual stress field: Analytical approach with experimental verification.

Shot peening is the most common surface treatment employed to enhance the fatigue performance of structural metallic materials and often carried out after other surface treatments. This paper mainly focuses on the effects of initial conditions of surface such as initial stress filed and hardness profile on shot peening residual stress field. The residual stress distribution induced by shot peening is obtained using Hertzian contact theory and elastic–plastic evaluation after yielding occurred during impingement and rebound of shots. Elastic plastic calculations are performed using different hardening models considering Bauschinger effect. The present model is able to predict redistribution of residual stresses in shot peening process by considering the initial conditions of target surface. Initial stress distribution and yield stress variation produced by previous surface treatments are taken into account by measuring residual stresses and hardness profile at near surface layers. An analytical parametric study is performed to evaluate the influence of initial conditions induced by surface pretreatments on shot peening residual stress field. The results of analytical model are validated by experimental data obtained in the literature as well as by our own measurements. The analytical results generally agree with the experimental measurements. [ABSTRACT FROM AUTHOR]