Mismatch effect on plastic yield loads in idealized weldments. II. Heat affected zone cracks

In Part I, accurate closed form solutions of mismatch yield loads were given in terms of strength mismatch levels, ligament-to-weld width ratios, and crack lengths, for a middle crack tension (M(T)) plate and a single edge cracked plate in pure bending (SE(PB)). The weld configurations were idealized as a simple strip model, and the crack was assumed to be located in the centre of the weld metal. Solutions were given for two limiting out-of-plane constraint conditions, plane strain and plane stress. This paper is a continuation of Part I, providing similar solutions of mismatch yield loads when the crack is in the interface between the weld and base plate. As in Part I, useful guidelines are given for assessing welded structures with heat affected zone (HAZ) cracks, in the form of windows where the plastic yield load solutions of mismatched components can be obtained assuming the component is wholly made of either base material or weld material properties. Such guidelines could be very useful when complex components with weldments are to be assessed, for which the plastic yield load solutions are not available or difficult to find. Moreover, the effect of the crack location within the weld metal as well as of the HAZ properties on the mismatch yield load solutions is briefly discussed.