A J-INTEGRAL ANALYSIS OF CRACKS IN OVERMATCHED WELDED JOINTS
高匹配焊接接头裂纹的J积分研究

The effects of material inhomogenity and weld width of the over- matched welded joints with a longitudinal crack or flaw upon the J-integral, a charac- terizing parameter for elastoplastic fracture, have been studied. The overmatched weld is idealized to be a parallelly cracked and sandwiched hard layer, the yield stress of which is higher than that of the base metal. Numerical solutions were ob- tained by using elastoplastic finite element method under the assumption of plane stress. The results show that the values of J-integral are remarkably affected by the mate- rial inhomogenity and the weld width especially when the nominal stress or nominal strain is comparatively high, which, therefore, should be taken into account when evaluating the crack driving force for a overmatched joint.