Numerical modeling of ultrasonic shot peening with an accurate impact velocity

Abstract

Ultrasonic shot peening (USP) uses the high-frequency motion of the shots with a random distribution of direction and velocity driven through ultrasonic resonance, thus obtaining a deeper gradient structural layer and a larger residual compressive stress. The variation rule of different parameters in the USP process is studied in detail through finite element simulation. To be closer to the experiment, the motion pattern of the shot is observed and repeatedly verified with the help of high-speed camera. After establishing the finite element model (FEM) of the impact of the random distribution of the shots, the motion characteristics are assigned to the shot in the form of probability density function (PDF). The evolution of shot peening coverage is calculated from the experimental and simulation results, and the patterns of residual stress, roughness, and plastic strain during the USP simulation are calculated. The results show that with the increase of shot peening coverage, the maximum residual stress (RS) and plastic strain increase gradually, and the variation rules of each roughness parameter with the coverage range are different, but the values are all within 10 μm. The modeling method used in this paper provides a new idea for the fine modeling of USP.