FEM analysis on the abrasive erosion process in ultrasonic-assisted abrasive waterjet machining

In this work, a finite element method (FEM) explicit dynamic simulation was employed to investigate the abrasive erosion process in ultrasonic-assisted abrasive waterjet (AWJ) machining. Johnson-Holmquist ceramic material model with failure criteria was utilized to realize the deletion of the failure elements for the simulation of material removal. The effects of impact angle and particle shape on the erosion rate were analyzed. The residual stress in workpiece induced by the erosion under the vibration condition was compared to that under the non-vibration condition. Furthermore, the ultrasonic-assisted erosion processes of multiple particles under different overlapping conditions on the impact areas were simulated. The simulation results show that the application of vibration can effectively improve the erosion rate and influences the contact process between the particle and the workpiece surface. The residual stress distribution in the section of workpiece parallel to the vibration direction is not symmetric under the vibration condition, which is quite different from the nearly symmetric one obtained without vibration.