Limit load and J estimates of a centre cracked plate with an asymmetric crack in a mismatched weld

摘要

The limit load and J estimates of a centre cracked plate with an asymmetric crack in the tensile properties mismatched weld were investigated. A limit load expression was derived on the basis of a simplified slip-line field. A good agreementbetween the predictions of the expression and finite element (FE) results was found for ratios of half-weld width to the crack ligament, H/l, of less than 0.5. The equivalent stress-strain relationship method (ESSRM) was used to predict elastic-plastic Jvalues. Results from FE analyses show that the ESSRM is accurate for the crack with asymmetry in the mismatched weld provided an accurate theoretical or numerical value of the limit load of the same specimen is available. Defect assessment methods arediscussed, and it is found that the failure assessment diagram (FAD) of an asymmetrically cracked mismatched weld can be constructed from the equivalent stress strain relationship for the same mismatched geometry with a symmetric crack. The effect of anasymmetric crack on the FAD may then be covered by the limit load solution for the asymmetrically cracked mismatched weld.