Prediction of failure in weldments - Part II: Joint with initial notch and crack

Mechanical defects such as notches and cracks in weldments undergoing gross yielding are analyzed. The redistribution of plastic stress and strain local to the notch and crack are determined including the effects of material nonhomogeneities that involve the weld metal, heat-affected zone and base metal. Failure predictions are made from the uniaxial data by application of the strain energy density theory in conjuction with the incremental theory of plasticity. More specifically, the fluctuations of the strain energy density function are identified with failure initiating from imperfection sites in weldments. The results are found to be highly nonlinear and depend sensitively on load history.