Three-dimensional finite-element procedures for shot peeening residual stress filed prediction

Shot peening is widely used to improve the performances of machine elements subjected to fatigue loading, stress corrosion cracking or fretting, mainly due to the favourable residual stress field induced. However, many times the choice of the treatment parameters is made by following empirical considerations that do not take the residual stresses into account and, consequently, do not allow to optimise the treatment results. To reach this objective it is necessary to accurately know the residual stress field induced by varying the shot peening parameters. Finite-Element analyses of shot peening, both axisymmetric and three dimensional, were developed to predict the residual stress field induced with different treatment parameters. Different approaches were used to evidence worths and limits of every one and to determine the numerical method that allows to reach the best results with the less expansive use of hardware and software.