Abstract: The effects of material inhomogeneity and weld width of the overmatched welded joints with a longitudinal crack or flaw upon the J-interal,a characterizing parameter for elastoplastic fracture,have been studied.The overmatched weld is idealized to be a parallelly cracked and sandwiched hard layer,the yieht stress of which is higher than that of the base metal.Numeri- cal solutions were obtained by using elastoplastic finite element method under the assumption of plane stress.The resuits show that the values of J-integral are remarkably affected by the material inhomogeneity ant the weld width especially when the nominal stress or nominal strain is comparatively high,which,therfore,should be taken into account when evaluating the crack driving force for an overmatched joint.

Key words: welded joint, crack, J-integral