| Shot peening is a surface enhancement process used to improve the fatigue strength of metals by introducing beneficial compressive residual stresses on the surface. Shot peening is widely used in a number of industrial applications, including gas turbine engines. However, the fatigue life improvement gained via shot peening is not explicitly accounted for in current engine components life prediction processes. Therefore, there is a significant potential for increasing the predicted damage tolerance capabilities of engine components if beneficial residual stress considerations are incorporated into the life prediction methodology. In this work, a finite element model was developed to apply residual stresses from shot peening as initial stresses to the finite element mesh. The proposed technique was validated using a simple numerical example and the sensitivity of the resulting stress distribution in the model was investigated. The capability of the proposed strategy was also demonstrated on a fatigue test specimen containing high stress concentration features, broadly used in gas turbine engine applications. With the proposed technique, the applied residual stress profile is not self-equilibrating. Therefore, a redistribution of stresses was found in the model after the application of the boundary conditions. The depth and magnitude of the tensile residual stresses had a significant influence on the resulting redistribution of stresses. |
