Finite element simulation of residual stress field induced by ultrasonic impact treatment

A 3D finite element model predicting the residual stress distribution induced by ultrasonic impact treatment (UIT) in the AISI 304 stainless steel was established. Effects of impact velocity, pin size, impact time, interfacial friction, multiple impacts and coverage were considered during the simulation. The results show that impact velocity, pin size, impact time and interfacial friction affect the final residual stress field. Impact velocity and pin diameter have a great influence on the distribution of residual stress field. The depth of the stress layer and the residual stress value increase along with the rising of pin diameter or impact velocity. However, friction coefficient has little influence on impact. According to the increase of impact time, the ultrasonic impact strengthening characteristic is obvious and the depth of the stress layer increases. Along with the increase of the coverage, the compressive residual stress layer gets thicker, but the formation of the maximum compressive residual stress value decreases.