Abstract: Finite element method is presented to attain the numerical simulation of residual stresses field in the material treated by laser shock processing. The distribution of residual stresses generated by single laser shock with square and round laser spot is predicted and validated by experimental results. With the FEM model, effects of different overlapping rates and impact sequences on the residual stresses distribution are simulated. And the results indicate that: (1) Overlapping laser shock can increase the compressive residual stresses. But it is not effective on the growth of plastically affected depth; (2) Overlapping rate should be optimized and selected carefully for the large area treatment. Appropriate overlapping rate is beneficial to obtain a homogeneous residual stress field; (3) Impact sequence has a great effect on the residual stress field. It can greatly attenuate the phenomenon of “residual stress hole” to obtain a homogeneous residual stress field.

Key words: Laser shock processing, Overlapping, Residual stress, Finite element method