Strength mis-match effect on limit loads for circumferential surface cracked pipes

The present work provides mis-match limit loads for welded pipes with constant-depth, circumferential part-through surface cracks in the centre of the weld metal. As limiting cases, circumferential through-wall and fully circumferential cracks are also considered. Based on systematic finite element limit analyses, mis-match limit loads are quantified by the strength mis-match ratio and only one geometry-related slenderness parameter, not requiring additional geometry-related parameters. This implies that mis-match limit loads for surface cracked pipes can be found from those for idealized axi-symmetric problems, which offers significant benefit in assessment of surface cracks in welds of pipes.