A CFD-FEM numerical study on shot peening

Abstract

Surface integrity after shot peening is affected by various parameters. Improper selection of shot peening parameters brings challenges in improving the component's fatigue life or even damages the original surface. An insight into the effects of shot peening parameters on surface integrity is a prerequisite for the appropriate setting of process parameters. This study used the computational fluid dynamics (CFD) method to establish a two-phase flow model describing relationships between shot velocity and pneumatic shot peening machine parameters, such as air pressure and peening distance. A random multi-shots finite element model (FEM) was established to study the effects of shot velocity and shot diameter on surface integrity. Results indicate that the peening distance and air pressure significantly affect shot velocity. Compared to increasing shot velocity, peening with larger diameter shots is more effective in generating compressive residual stress (CRS) and dislocation cell refinement layers. However, it results in a decline in the magnitude of surface compressive residual stress (SCRS). Double shot peening combines the characteristics of different diameter shots, which introduces high SCRS and considerable CRS layer thickness.