Effect of initial surface finish on effectiveness of shot peening treatment using enhanced periodic cell model

Abstract

In this paper, we investigate the effect of the initial surface finish of the target on shot peening effectiveness using realistic 3D finite element simulations. Specifically, a large number of random shot impingements were simulated using an enhanced periodic cell model. The target material which is made from TI-6Al-4V is assumed to be strain-rate sensitive and follows the kinematic hardening law. ABAQUS/PYTHON scripts were developed to average the peening residual stresses at each depth of the target, and to calculate the corresponding surface roughness. The simulation was validated by comparing the results with the published work in literature. The periodicity of the model was also examined and verified. The model is further used to investigate the effect of the initial surface roughness on the effectiveness of the shot-peening treatment. The evolutions of the residual stress, plastic strain and the surface morphology during the peening process have all been investigated and the results discussed. The work reveals that a rough surface finish can lead to major reduction in the effectiveness of the shot peening treatment in terms of the generation of the highly beneficial compressive residual stresses.