In BS 7448, Part 2, the stress intensity factor, J-integral and crack tip opening displacement (CTOD) equations developed for evaluation of fracture toughness of a homogeneous material using experimentally measured quantities, such as load-load line displacement, are applied to SE(B) specimens with yield-strength-mismatched welds. The accuracy of this procedure was studied by Gordon and Wang using finite element analysis (FEA). Recently, the so-called “η factor” method for J-integral evaluation of SE(T) specimens with weld-center-line-cracked and yield-strength-mismatched welds was studied by Ruggieri using detailed FEA calculations and the load separation method proposed by Paris et al. For application to strain-based design of pipelines, CANMET has developed equations to evaluate J-integral and CTOD resistance curves for clamped SE(T) specimens of homogeneous materials using experimentally measured load and crack-mouth-opening displacement (CMOD) in a single-specimen procedure similar to that in ASTM E1820. In the present study, the accuracy of using these equations for J-integral evaluation of clamped SE(T) specimens with weld-center-line-cracked and strength-mismatched welds was studied. It was found that the errors in J and CTOD using the equations developed for SE(T) specimens of homogenous materials for these strength-mismatched welds are similar to those for SE(B) specimens with the same weld geometry and mismatch level as reported by Gordon and Wang. It was also found that using the higher of the strength of base and weld metals σY (= (σYS+σTS)/2), (i.e. (σY)w for overmatching and (σY)B for undermatching) in converting J to CTOD gives reasonable and conservative CTOD evaluations for specimens with weld-center-line-cracked and yield-strength-mismatched welds.
- Pressure Vessels and Piping Division
Evaluation of J/CTOD for Clamped SE(T) Specimens With Welds
- Views Icon Views
- Share Icon Share
- Search Site
Shen, G, Tyson, WR, Gianetto, JA, & Park, D. "Evaluation of J/CTOD for Clamped SE(T) Specimens With Welds." Proceedings of the ASME 2011 Pressure Vessels and Piping Conference. Volume 6: Materials and Fabrication, Parts A and B. Baltimore, Maryland, USA. July 17–21, 2011. pp. 861-866. ASME. https://doi.org/10.1115/PVP2011-57038
Download citation file: