Construction of shot peening enhanced response surface model based on DEM-FEM coupling and the influence analysis of process parameter

In order to simulate the shot peening process and realize the rapid prediction of the shot peening effect, a random multi-shot pellet shot peening strengthening model was established based on Abaqus software using the discrete element method-finite element method (DEM-FEM) coupling, and the TC4 titanium alloy was used as the research object to carry out the shot peening strengthening test to verify the accuracy of the coupling model. The Box-Behnken design (BBD) method was used to design a three-factor and three-level shot peening simulation test scheme for the three process parameters of projectile size, shot peening speed and shot peening coverage.The surface residual stress value and surface roughness value were obtained by simulation analysis, and the numerical fitting was carried out by Design-Expert software. Finally, the function models between the shot peening process parameters and the surface residual stress or surface roughness were obtained, the interaction between the three factors of projectile size，shot peening speed and shot peening coverage was analyzed by the response surface method, and the influence law of shot peening strengthening effect was analyzed.The results show that the error between the results of the response surface prediction model and the simulation calculation results is less than 5%, the established response surface prediction model has high approximate accuracy and reliability，and the effective prediction of shot peening effect can be achieved by using this model.