A methodology to predict the roughness of shot peened surfaces

Several industrial processes, such as peening processes, are used to generate compressive stresses in mechanical parts through multiple impacts. A model of shot peening has been developed, simulating multiple impacts with a deterministic distribution by using a semi analytical method to predict the surface roughness of an initially perfectly flat semi infinite surface. The model only uses the process parameters and material data as input and is industrially directly applicable. The model is validated through comparison with roughness measurements of surfaces peened with an ultrasonic process. The robustness of the model is tested through the influence of the number of impacts simulated. Insights on the influence of process parameters on the surface geometry are given for ranges of parameters typical of the ultrasonic shot peening process of common metallic materials. The influence of the material's hardening behaviour is also studied.