The paper examines the problems associated with applying proof-test-based life prediction to vessels made of high-toughness metals. Two A106 Gr B pipe specimens containing long, through-wall, circumferential flaws were tested. One failed during hydrostatic testing and the other during tension-tension cycling following a hydrostatic test. Quantitative fractography was used to verify experimentally obtained fatigue crack growth rates and a variety of LEFM and EPFM techniques were used to analyze the experimental results. The results show that: plastic collapse analysis provides accurate predictions of screened (initial) crack size when the flow stress is determined experimentally; LEFM analysis underestimates the crack size screened by the proof test and overpredicts the subsequent fatigue life of the vessel when retardation effects are small (i.e., low proof levels); and, at a high proof-test level 2.4 × operating pressure), the large retardation effect on fatigue crack growth due to the overload overwhelmed the deleterious effect on fatigue life from stable tearing during the proof test and alleviated the problem of screening only long cracks due to the high toughness of the metal.

Anderson, T. L., 1991, Fracture Mechanics Fundamentals and Applications, CRC Press, Boca Ratan, LA.
ASME Boiler and Pressure Vessel Code, 1992, Appendix H of Section IX.
Broek, D., 1986, Elementary Fracture Mechanics, Martinus Nijhoff Publishers, Dordrecht.
EPRI, 1988, “Evaluation of Flaws in Ferritic Piping,” EPRI NP-6045, Palo Alto, CA.
Fearnebough, G. D., 1973, “Macroscopic Aspects of Ductile Crack Extension and Its Relevance to Engineering Structures,” Conference on Mechanics and Mechanisms of Crack Growth, Cambridge, Apr., pp. 8–10.
Formby, C. L., 1972, “Desirability of Proof Testing Reactive Pressure Vessels Periodically,” I. Mech. E. Conference on Periodic Inspection of Pressure Vessels, London, U.K., May.
Jack, A. R., and Price, A. T., 1971, “Use of Crack Initiation and Growth Data in the Calculation of Fatigue Lives of Fatigue Specimens Containing Defects,” Metal Construction, Nov.
Kanninen, M. F., and Popelar, C. H., 1985, Advanced Fracture Mechanics, Oxford University Press, New York, NY.
Kumar, V., German, M. D., Wilkening, W. W., Andrews, W. R., deLorenzi, H. G., and Mowbray, D. F., 1984, “Advances in Elastic-Plastic Fracture Analysis,” EPRI NP 3607, Palo Alto, CA.
Lane, P. H. R., and Rose, R. T., 1961, “Comparative Performance of Pressure Vessels Under Pulsating Pressure,” I. Mech. E. Conference on Pressure Vessel Research Toward a Better Design, Jan.
NASA/FLAGRO, 1988, Fatigue Crack Growth Computer Program, NASA JSC-22267.
Nelson, D. V., 1975, “Review of Fatigue-Crack-Growth Prediction Under Irregular Loading,” SESA Spring Meeting, Chicago, IL, pp. 11–12.
Vassilaros, M. G., Hays, R. A., and Gudas, J. P., 1986, “J-Resistance Curve Analysis for ASTM A106 Steel 8 inch Diameter Pipe and Compact Specimens,” Fracture Mechanics, 17th Vol., ASTM STP 905, eds., J. H. Underwood, R. Chait, C. W. Smith, D. P. Wilhem, W. A. Andrews, and J. C. Newman, ASTM, Philadelphia, PA.
Zahoor, A., 1989, Ductile Fracture Handbook, EPRI NP-6301-D, Palo Alto, CA.
This content is only available via PDF.
You do not currently have access to this content.