Abstract
Based on the reference stress approach, two sets of the crack opening displacement (COD) estimation equations are proposed for a complex cracked pipe. One set of equations can be used for the case when full stress-strain data are known, and the other for the case when only yield and tensile strengths are available. To define the reference stress, a simple plastic limit analysis for the complex cracked pipe subject to combined bending and tension is performed, considering the crack closure effect in the compressive-stressed region. Comparison with ten published test data and the results from the existing method shows that the present method not only reduces non-conservatism associated with the existing method, but also provides consistent and overall satisfactory results. These results provide sufficient confidence in the use of the present method to estimate the COD (and thus the leak rate) for the Leak-before-Break (LBB) analysis of complex cracked pipes. Finally, the J-estimation equations are also provided for complex cracked pipes, for the LBB analysis of complex cracked pipes.
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References
Ainsworth, R.A. (1984). The assessment of defects in structures of strain hardening materials. Engineering Fracture Mechanics 19, 633–642.
France, C.C., Hooton, D.C. and Sharples, J.K. (1996). New stress intensity factor and crack opening area solutions for through-wall cracks in pipes and cylinders. AEA Technology Report AEAT–0643.
Kim, Y-J. and Budden, P.J. (2000) Reference stress approximations for J and COD of circumferential through-wall cracked pipes. International Journal of Fracture, submitted.
Kim, Y-J., Huh, N-S. and Kim, Y-J. (2000) Enhanced reference stress based J and COD estimation method for LBB analysis and comparison with GE/EPRI method. Fatigue and Fracture of Engineering Materials and Structures, submitted.
Kramer, G. and Papaspyropoulos, V. (1986). An assessment of circumferentially complex-cracked pipe subjected to bending. NUREG/CR-4687.
Kumar, V. and German, M.D. (1988). Elastic-plastic fracture analysis of through-wall and surface flaws in cylinders. EPRI Report NP-5596.
Miller, A.G. (1988) Review of limit loads of structures containing defects. International Journal of Pressure Vessels and Piping 32, 191–327.
Pipe Fracture Encyclopedia, Volume 3: Pipe Fracture Test Data, (1997). Battelle.
Rahman, S., Brust, F.W., Ghadiali, N. and Wilkowski, G. (1998a). Crack-opening-area analyses for circumferential through-wall cracks in pipes – part I: analytical models. International Journal of Pressure Vessels and Piping 75, 357–373.
Rahman, S., Brust, F.W., Ghadiali, N. and Wilkowski, G. (1998b). Crack-opening-area analyses for circumferential through-wall cracks in pipes – part II: model validations. International Journal of Pressure Vessels and Piping 75, 375–396.
Zahoor, A. (1991). Ductile Fracture Handbook. Novetech Corp.
R6: Assessment of the integrity of structures containing defects (1999). British Energy Generation Ltd.
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Kim, YJ., Huh, NS. & Kim, YJ. Crack opening analysis of complex cracked pipes. International Journal of Fracture 111, 71–86 (2001). https://doi.org/10.1023/A:1010945514752
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DOI: https://doi.org/10.1023/A:1010945514752