Abstract: In view of the high turbulence behavior of water jet and the complex elasticity plastic deformation behavior of peened target material, this paper provides an analysis method of finite element for water jet peening strengthening residual stress field. Base on the quasi-static pressure distribution and non-linear axis symmetrical surface-distribution load, an elastic-plastic model with non-relevant Mises rate of multilinear isotropic hardening, Prandtl-Reuss plastic incremental theory and incremental initial stress method, and linear slope load loading system are adopted, and the finite element software ANSYS is used to simulate the residual stress fields produced on the surface layer of 2A11 aluminum alloy material by water jet peening under different pressures, thereby the distribution law of residual stress field and the variation law of residual stress along layer depth and radial direction are revealed. It is pointed out that the residual stress along layer depth is divided into residual pressure stress area and residual tensile stress area, and the residual stress along radial direction is divided into the first residual pressure stress area, residual tensile stress area and the second residual pressure stress area. It is found that the surface residual pressure stress, the biggest residual pressure stress on the surface layer and the depth of residual pressure stress layer augment with the increase of peening pressure. In order to verify the correctness of the finite element simulation, the residual pressure stress on peening surface is tested. The results show that the surface residual stress value calculated by finite element method is proximate to the test data.

Key words: Finite element method, Numerical simulation, Peening, Residual stress field, Water jet