Prediction of failure in weldments - Part I: Smooth joint

This investigation is concerned with predicting failure initiation sites ina butt weld joint under bending. The nonuniform load transmission characteristics through the weld metal, heat-affected zone and base material resulting from alteration in their microstructure are reflected through the macroscopic yield strength parameter. Elastic-plastic stress and strain redistribution is obtained for each increment of load increase. Analyzed in detail are the contours of constant strain energy density for determining the local and global stationary values which are assumed to be related to failure and stability of the system. Failure is predicted to initiate in the heat affected zone at the site of maximum of the minimum local strain energy density function. This corresponds to the experimental observation where cracking starts from the side of the butt joint where local stretching is maximum.