Investigation of CMOD based ri factors for clamped SET specimens with mismatched weld based on finite element analyses

This work studies the J-integral of weld centerline crack using clamped single-edge notched tension (SETc) specimens. Extensive finite element analyses (FEA), covering both plane-strain and three-dimensional SETc specimens with mismatched weld, are carried out to evaluate plastic ri factors for estimating the J-integral based on load-displacement curve. A wide range of specimen configurations and material properties, including different crack size, specimen width, weld width, strain hardening exponent, weld strength mismatch and the ratio of elastic modulus to yield stress, is considered in present FEA. Based on the results obtained from FEA, the effects of specimen configurations and material properties on plastic ri factors are examined and a set of fitting formulae for the plastic ri factor is proposed. The proposed ri factors are applicable in improved estimation of Jintegral for welded SETc specimens with weld centerline crack.