Residual Stresses in Weld Repairs and Mitigation by Design

It is well known that residual stresses caused by weld repairs tend can be significantly higher than those caused by initial fabrication welds due to severe restraint conditions associated with typical weld repairs. This paper presents an in-depth investigation of repair weld geometry effects on residual stress distribution characteristics, particularly in terms of the through-thickness membrane and bending content that can be shown fundamentally different from that in initial fabrication welds. The results indicate that repair weld design parameters in terms of repair length, depth, and width are of critical importance to the mitigation of residual stresses. A 3D finite element residual stress modeling procedure developed and validated for numerous case studies in the past, after further validation on a selected component in the current study, is used throughout this investigation.