Study on shot peened residual stress distribution under cyclic loading by numerical analysis

To prevent stress corrosion cracking or to extend the fatigue life of structures, various peening techniques are employed. In this research, to reproduce the residual stress distribution after shot peening, the residual stress due to multi-pass welding was predicted and the analysis of shot peening considering the welding residual stress distribution was conducted using the analysis system proposed by the authors, which was based on high-speed non-linear FE analysis method named Idealized Explicit FEM. The analyzed residual stress distribution due to the shot peening was compared with the experimental measurement using X-ray diffraction. As a result, it was found that the predicted residual stress distribution well reproduces the residual stress distribution after shot peening. To evaluate the effect of shot peening under the various loading conditions, tensile and compressive cyclic load was applied to the pipe joint on the numerical analysis considering the residual stress after shot peening. As a result, it was found that the influence of tensile cyclic load on the residual stress distribution is small while the compressive residual stress due to peening is decreased by the compressive cyclic load in the targeted pipe joint.