Analysis of tubular joint with weld toe crack by finite element methods

Finite element methods are used to obtain the through-thickness and surface stresses for the tubular T-joint in the presence of a shallow weld toe crack. The crack tip stress intensity factors are obtained by comparing the stresses at the crack front with the theoretical solution. The embedded elliptical crack front is modelled as straight line segments. The region at the vicinity of the crack is discretized using special elements, which produce singular stress fields at the crack front. It is observed that in presence of a shallow weld toe crack, the stress along the chord surface near the weld toe is less than that of a joint without a crack; which is evident from the presence of the free surface of the crack face. But far from the crack, the stress is always greater than that of the uncracked joint.