It is now well-known in the fracture-mechanics community that a single fracture parameter alone may not be adequate to describe crack-tip condition. To address this problem, there has been a recent surge of interest in crack-growth behaviour under conditions of low crack-tip stress triaxiality. This paper exploited the K-A3 crack approach, which was derived from a rigorous asymptotic solution and has been developed for a two-parameter fracture.
The material failure curve or master curve, has been established as a result of the notched specimen tests. It was shown that the notch fracture toughness is a linear decreasing function of the stress. The use of the material failure curve to predict fracture conditions was demonstrated on gas pipes with the longitudinal surface notch.
No finding.
This approach requires that the constraint in the test specimen approximate that of the structure to provide an “effective” toughness for use in a structural integrity assessment. The appropriate constraint is achieved by matching thickness and crack depth between the specimen and structure.
