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An Empirical Model for Environmental Damage at the Crack Tip

Published online by Cambridge University Press:  21 February 2011

K. -M. Chang
K. -M. Chang*
Affiliation:
General Electric Company, Corporate Research and Development, P.O. Box 8, Schenectady, NY 12301
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Abstract

An experimental method that is able to verify and to characterize the damage zone developed in front of crack tip under time-dependent fatigue crack propagation has been established. The crack growth rate was found to decrease exponentially in the damaged zone. Such a crack growth behavior can be described by a mathematical model which only requires three parameters: initial crack growth rate, (da/dN)q; normal crack growth rate (da/dN)o; and damaged zone size, D. An analyticat relationship has been developed to correlate the temperature and the time of sustained loading to the size of the induced damaged zone.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 125: Symposium N – Materials Stability and Environmental Degradation , 1988 , 243
Copyright
Copyright © Materials Research Society 1988

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References

REFERENCES

[1] Solomon, H.D. and Coffin, L.F. Jr., ”Effects of Frequency and Environment on Fatigue Crack Growth in A286 at II00°F,” Fatigue at Elevated Temperatures, (ASTM STP 520, Amer. Soc. Test. Mat. 1973) 112–122.Google Scholar
[2] Cowles, B.A. et al., “Cyclic Behavior of Turbine Disk Alloys at 650°C,” J. Eng. Mat. Tech., 102 (Oct. 1980) 356–363.Google Scholar
[3] Chang, K.-M., ”Time Dependent Fatigue Crack Propagation in Inconel 718 Superalloys,” Mechanical Behaviour of Materials - V Proc. 5th Int. Conf., Beijing, China, June 1987, ed. Yan, M.G. et al., Pregamon Press, Oxford, UK, 1139–1147.Google Scholar
[4] Chang, K.-M., “Elevated Temperature Fatigue Crack Propagation after Sustained Loading,” Effects of Load and Thermal Histories on Mechanical Behavior of Materials Proc. TMS Spring Meeting, Denver, CO, 1987, ed. Liaw, P.K. et al., AIME-TMS, 13–26.Google Scholar
[5] Swalbe, K.-H. and Hellmann, D., “Application of the Electrical Potential Method to Crack Length Measurements Using Johnson's Formula,” J. Eng. Mat. Tech., JTEVA 9 (3)(May 1981) 218–221.Google Scholar
[6] Tada, H., Paris, P., and Irwin, G., The Stress Analysis of Cracks Handbook, (Del Research Corp. 1973) 2.10–2.12.Google Scholar
[7] “Constant-Load-Amplitude Fatigue Crack Growth Rates Above 10−8m/ Cycle,” 1980 Annual Book of ASTM Standard, Part 10, E 647–78T.Google Scholar
[8] Henry, M.F., private communications.Google Scholar
[9] Rhee, S.K. and Spencer, A.R., “Oxidation of Commercial High-Temperature Alloys,” Met. Trans. A, 1 (July 1970) 2021–2022.Google Scholar