Surface integrity of gear shot peening considering complex geometric conditions: A sequential coupled DEM-FEM method

Abstract

Shot peening is widely used in gear surface strengthening. Due to the complex 3D geometry of the gear target, the collision of shots occurs in the tooth space, resulting in the different shot dynamic and nonuniform features of surface integrity along the tooth profile. The existing models cannot accurately predict the surface integrity of gear shot peening, which hinders the process improvement. In this paper, a sequential coupled DEM-FEM method is proposed. The DEM model is used to represent the collision between shots and the final velocity distribution. Besides, with the determined shot kinematics, the FEM simulation for the gear shot peening process and its time optimization strategy are presented. The proposed method is validated by the gear shot peening tests. Based on the proposed method, the influence of gear geometry on shot impacts and uniformity of tooth surface integrity (surface roughness, surface topography, and compressive residual stress field) is investigated. This study provides an effective tool for optimizing gear shot peening technology and could be extended to other industrial parts with complex shapes.