L51489 The Effect of Misalignment on the Fracture Behavior of Girth Welds

Many pipeline codes have introduced, or are about to introduce, alternative acceptance criteria for defects. Most of these alternative acceptance criteria are based on a CTOD toughness approach and many have been validated using full-scale tests. These approaches have been shown to be conservative using well-aligned pipe tests. It has been shown, however, that the likelihood of producing defects in a girth weld is considerably increased when misalignment is present. In this case, it is not known whether misalignment would reduce the level of conservatism in the proposed engineering critical analyses. This present program has used finite element analyses and full-scale tests to evaluate the effect of misalignment on fracture. Finite element calculations were performed using two- and three-dimensional analyses.