Abstract: In view of the liquid-solid turbulence behavior of premixed water jet and multiple nonlinear coupling behavior in shot peening process, an analysis method of finite element for jet peening strengthening residual stress field is provided in this article. The liquid-solid two-phase flow theory and computational fluid dynamics method are used to analyze the internal flow characteristics of the nozzle, and the jet shot peening model of multiple projectiles is established. Based on projectile speed impact load loading system, an elastic-plastic model with multilinear isotropic hardening and dynamic contact symmetric penalty function method are adopted, and the finite element software ABAQUS is used to simulate the residual stress fields produced on the surface layer of 45 steel by jet peening under different number of projectiles, thereby the distribution law of residual stress field and the variation law of residual stress along depth are revealed. It is found that the internal flow of the jet nozzle presents a homogeneous flow pattern. The variation law of the radial residual stress along the depth produced by different number of projectiles jet peening on the surface layer of the material is the same. But the radial residual pressure stress value on the surface of the material is greatly affected by the shot peening model, for the multiple projectile shot peening model, whose projectiles are arranged in 3 layers, the radial and circumferential center distance between adjacent projectiles are all the radius of the projectile, the surface radial residual pressure stress value calculated by numerical simulation is proximate to the test data of jet shot peening.

Key words: premixed water jet, peening strengthening, shot peening model, residual stress field, numerical simulation