Numerical simulation on residual stress eliminated by shot peening using SPH method

Abstract

The residual stress in the vacuum vessel of future magnetic confinement nuclear fusion reactors should be eliminated either during the welding process or after the welding is completed. Shot peening is an effective method to eliminate welding residual stresses. In order to investigate the effect of shot peening on welding residual stress, a numerical simulation on eliminating the welding residual stress by shot peening using smoothed particle hydrodynamics (SPH) was performed. A model based on the SPH theory was established, the change of welding residual stress during the shot peening process was investigated. In addition, the change of welding residual stress before and after shot peening was studied. The effect of shot peening speed on residual stress was analyzed. The results demonstrated that the maximum residual stress changes continuously during shot peening. Moreover, shot peening can significantly improve the lateral and longitudinal residual stresses, but no obvious changes were found in the residual stresses along thickness direction. The shot peening speed affected the residual stress elimination effect, which provides guidance for the actual production process.