Optimization of the fatigue strength of materials due to shot peening : A survey

Abstract

Imparting residual compressive stresses in the surface layers of metallic components is one of the ways to improve their fatigue strength characteristics. Shot peening is employed for imparting residual stresses by means of cold work. Shot peening is a complex random process with many input variables. The material responses include residual stresses, cold work, surface roughness, micro-cracks and micro-structure changes. To obtain the maximum fatigue strength, the designer needs to consider both favorable and detrimental aspects of these responses together. The prediction of the responses from the input parameters involves many methods spanning across multiple-disciplines such as plasticity, fracture, optimization etc. The paper presents an overview of the studies that predict the various material responses and suggests a method based on continuum mechanics in order to optimize the fatigue strength of any material.