New ‘ηpl'' and ‘γ'' functions to evaluate J–R curve from cracked pipes and elbows. Part II: experimental and numerical validation

Experimental evaluation of J–R curve in a crack growth situation requires ‘η_pl' and ‘γ' functions that are specific to a cracked geometry and loading condition. In Part I [Engng. Fract. Mech., in press] of this paper, new η_pl and γ functions, which are not available in the literature, for pipe and elbow geometry with various crack configurations under different loading conditions have been derived. In this paper, some of these newly proposed η_pl and γ functions have been validated experimentally through comparison of crack initiation load and J–R curve. In few cases, numerical validation has also been provided by comparing the J-integral values calculated through η factor approach and finite element method.