## 1 Introduction
[25] performed shot peening, severe shot peening, re-shot peening and precise grinding combined simulation and experiments, tested the depth and value of residual stress of workpiece after different combined machining, and analyzed the law of combined process on fatigue life of workpieces. The scholars mentioned above combined the results of shot peening simulation and experiments, considered the effect of the former process on shot peening, analyzed the interaction between shot peening and other processes, and finally predicted and analyzed the microstructure, mechanical properties, residual stress distribution, and fatigue life of the workpiece after the combined machining. However, during the combinatorial analysis, it is assumed that the workpiece processed, when shot peening is the first process, it is a smooth surface or only extracts the stress field after the previous process as the initial condition for subsequent shot peening, ignoring the change of surface deformation or surface topography caused by a former mechanical process. After years of research and development, the simulation models built in the process of shot peening research transformed from 2D to 3D models and gradually developed into a combination of various processes. As the foundation of the shot peening model, the single-shot peening model plays a crucial role in mechanism research on the impact process of shot peening. The modeling process gradually considers the influence of original residual stress on the shot peening effect, and the model could comprehensively analyze the shot peening parameters and explain the processing phenomenon well [26; 27]. However, in most of the shot peening simulation studies, the surface shape of the target material surface is neglected as a smooth surface, and the simulation process ignores the influence of surface topography on simulation results. Therefore, to make up for the current stage of shot peening simulation research mainly based on smooth surfaces, ignoring the shortcomings of the initial shape of the workpiece surface on the impact of the shot peening process, the paper mentioned a rough surface single-shot peening simulation model. The model considers the effect of target material surface roughness and surface topography on shot peening and sets the surface of the target material as a rough surface. The target material surface changes into an anon-ideal smooth surface, and the change of surface roughness due to the removal of workpiece surface material due to machining are considered in the simulation. Therefore, the rough surface shot peening model is more consistent with the actual processing situation, and the simulation results could be more consistent with the actual processing result. In this paper, a rough surface solid model was constructed by using the spline curve generated by W-M fractal dimension theory, and a rough surface shot peening simulation model was built based on the constructed rough surface solid model. The paper is based on the rough surface shot peening simulation model to analyze the law of surface roughness, surface topography, and impact positions on surface deformation and surface residual stress. This study carried out shot peening experiments on different rough surfaces, and compared the surface topography, pit sizes, and surface residual stresses before and after shot peening to verify the effectiveness of the established simulation model. The single-shot peening simulation model established in this paper can be used for the subsequent development of the multi-shot peening model and provides a new research idea for shot peening simulation.