Analysis of residual stress of gear tooth root after shot peening process

Tooth breakage caused by microcracks at tooth root produced during gear service threatens production safety. Shot peening technology produces elastic-plastic deformation on the surface of the tooth root through the high-speed impact of projectiles. The residual stress induced by shot peening inhibits crack initiation and propagation as well as prolongs the gear service life. In this study, to optimize the shot peening process of the tooth root, the contour method is used to measure the residual stress distribution at the tooth root. A simulation model is established based on the discrete element method and finite element method (DEM-FEM) coupling method, and the effects of different projectile parameters on the residual stress distribution are studied through experimental verification. The results suggest that the greater the equivalent stiffness of the projectile impact, the greater the compressive residual stress; the greater the kinetic energy of the projectile, the greater the compression zone depth. The established shot peening simulation model provides a reference for improving the shot peening process.