Fracture mechanics analysis of heterogeneous welds : validation of a weld homogenisation approach

Flaw assessments assume homogeneous material properties, but welds are heterogeneous. The authors have developed a method to address heterogeneity in the estimation of crack driving force. This paper presents a numerical validation of the proposed approach. Weld heterogeneity is characterized in three pipeline girth welds by means of hardness mapping. The resulting distributions are input into a finite element model of a clamped SE(T) specimen. Following, crack tip opening displacement responses of heterogeneous welds are compared with predictions. The approach is found to strongly simplify analyses involving heterogeneous welds while maintaining an acceptable level of accuracy with respect to load