Effect of residual stress introduced by local loading on fracture behaviour of DMWJ under different constraints

Abstract

Taking nuclear safety end dissimilar metal welded joint (DMWJ) as the research object, the single edge-notched bend (SENB) specimen with a central crack was selected. Different pre-loads were applied to three local regions of the SENB specimen respectively to generate stresses at crack tip, and these stresses were introduced into the SENB specimen as residual stresses by restart method. The fracture behaviour of DMWJ under various constraints considering residual stress was systematically studied and compared with that under whole loading. The results showed that when the pre-load was located on different local regions, the tensile or compressive stress was generated, and resulted in the decreasing or increasing of J-R curve. The local loading was more consistent with the engineering practice than the whole loading. Compared with the low constraint SENB specimen, the J-R curve of high constraint SENB specimen was more sensitive to the change of residual stress.