Effect of surface roughness on evolution of residual stress field induced by shot peening

To reveal the effect of surface roughness on the distribution of residual stress induced by shot peening, a two-dimensional FE model incorporating cosine profile surface roughness was developed. The ABAQUS/EXPLICIT was used to simulate the shot peening process. Effects of the shot size and the impact velocity on residual stress field with the same surface roughness were investigated. A comparison was performed between the results from rough surface and those from perfect smooth surface. It is found that the surface roughness makes the compression stress zone become thinner. Meanwhile, it also can lead to the generation of tension stress on the surface of the target, which is harmful to the improvement of fatigue resistance. Therefore, the surface of the target should be as smooth as possible.