Abstract In this study, a computational procedure capable of evaluating the J-integral for mode I crack in welds is presented. An uncoupled three-dimensional thermal elastic–plastic finite element method is utilized to obtain residual stress distributions in welds. The resulting residual stress fields are then fed into the subsequent fracture mechanics analysis of mode I crack in welds. Moreover, analytical expression of the J-integral for mode I crack in a three-dimensional residual stress bearing body which yields domain-independent values is given in a form suitable for the numerical analysis. The J-values for the combined residual and mechanical loading are calculated and discussed.