A computational approach for fatigue life prediction in shot peened welded specimens

Abstract

We describe a computationally efficient approach for predicting residual stresses induced by the shot peening process on welded specimens with simple geometry. Using this approach, we are able to simulate impact between tens of thousands of rigid shots and a deformable workpiece, which to the best of our knowledge goes significantly beyond the work reported so far in previous simulation efforts by others. Simulations of Almen strip peening show very good correlation with prior experimental and analytical works, validating the soundness of our numerical approach. Furthermore, we show that using this approach, it is relatively straightforward to incorporate pre-existing residual stresses from welding, and using a numerical approach rooted in fracture mechanics, we make the ultimate connection between residual stresses and the growth life of fatigue cracks in these specimens. We conclude our paper by contrasting model predictions with experimentally observed fatigue data.