Browse > Article

Crack Opening Area Assessment of Circumferential Though Wall Crack in a Pipe Subjected to Tension and Bending  

Kim, Sang-Cheol (Department of Occupational Health and Safety Engineering, Semyung University)
Kim, Maan-Won (GNEC Inc.)
Publication Information
Journal of the Korean Society of Safety / v.23, no.5, 2008 , pp. 61-66 More about this Journal
Abstract
It is important to calculate the exact crack opening area in the cracked pipe subjected to axial force and bending moment. Among many solutions for obtaining the crack opening displacement, Paris-Tada's expression, which is derived from energy method, is open used in fracture analysis for piping crack problems because of its simplicity. But Paris-Tada's equation has conservativeness when radius over thickness ratio(R/t) is ten or less, for it is based on the stress intensity factor solution having a compliance function derived from a simple shell theory. In this paper we derived a new expression using a different stress intensity factor solution which is able to consider the variation of compliance through wall thickness in a cracked pipe. Conservativeness of both equations was examined and compared to finite element analysis results. Conservativeness of the new equation is decreased when R/t > 10 and increased slightly when R/t < 10 compared with Paris-Tada's. But Both equations were highly conservative when R/t < 10 compared with finite element analysis results.
Keywords
crack opening area; through wall crack; stress intensity factor; tensile and bending compliance; finite element analysis;
Citations & Related Records
연도 인용수 순위
  • Reference
1 P. Paris and H. Tada, "The Application of Fracture Proof Design Methods Using Tearing Instability Theory to Nuclear Piping Postulating Circumferential Through Wall Cracks", NUREG/CR-3464, September 1983
2 H. Tada, "The Effects of Shell Corrections on SIFs and the Crack Opening Area of a Circumferential and a Longitudinal Through Crack in a Pipe", in NUREG/ CR-3464, p. 71, 1983
3 A. Zahoor, Ductile Fracture Handbook. Volume 1, Circumferential Throughwall Cracks, Electric Power Research Institute, Palo Alto, CA, 1989
4 A. Zahoor, "Closed Form Expressions for Fracture Mechanics Analysis of Cracked Pipes", ASME J. of PVT, Vol. 107, pp. 203-205, 1985
5 V. Kumar, M. D. German, W. W. Wilkening, W. R. Andrews, H. G. deLorenzi, and D. F. Mowbray, "Advanced in Elastic-plastic Fracture Analysis", EPRI NP-3607, EPRI, Palo Alto, CA, 1984. 8
6 J. L. Sanders, Jr., "Circumferential Through Crack in a Cylindrical Shell under Combined Bending and Tension", SAME J. of Applied Mechanics, Vol. 50, p. 221, 1983