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Characteristics of elastic waves generated by crack initiation in aluminum alloys under fatigue loading

Published online by Cambridge University Press:  31 January 2011

Kiwoo Nam
Affiliation:
Division of Materials Science and Engineering, PuKyong National University, Nam-ku, Pusan, 608–739, Korea
Ajit Mal
Affiliation:
Mechanical and Aerospace Engineering Department, University of California, Los Angeles, California 90095
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Abstract

The characteristics of elastic waves emanating from crack initiation in 2024 and 5052 aluminum alloys subject to static and fatigue loading were investigated through laboratory experiments. The objective of the study was to determine the differences in the properties of the signals generated from static and fatigue tests and also to examine if the sources of the waves could be identified from the temporal and spectral characteristics of the acoustic emission waveforms. The signals were recorded using nonresonant, flat, broadband transducers attached to the surface of the alloy specimens. The time dependence and power spectra of the signals recorded during the tests were examined and classified according to their special features. Three distinct types of signals were observed. The waveforms and their power spectra were found to be dependent on the material and the type of fracture associated with the signals. Analysis of the waveforms indicated that some signals could be attributed to plastic deformation associated with static tests. The potential application of the approach in health monitoring of aging aircraft structures using a network of surface mounted broadband sensors is discussed.

Type
Articles
Copyright
Copyright © Materials Research Society 2001

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References

REFERENCES

1.Aging of U.S. Air Force Aircraft, Publication NMAB-488-2 (National Academy Press, Washington, DC, 1997).Google Scholar
2.Annual Book of ASTM Standards, Section 3, “Metals Test Methods and Analytical Procedures,’ Vol. 3: Nondestructive Testing (ASTM, Philadelphia, PA, 1993).Google Scholar
3.Acoustic Emission Testing, Nondestructive Testing Handbook Vol. 5 (ASNT, Columbus, OH, 1987).Google Scholar
4.Carpenter, S.H. and Gorman, M.R., J. Acoustic Emission 13, 51 (1995).Google Scholar
5.Buttle, D. and Scruby, C., J. Acoustic Emission 9, 243 (1990).Google Scholar
6.Heiple, C., Carpenter, S., and Armentrout, D., J. Acoustic Emission 10, 103 (1992).Google Scholar
7.McBride, S., Maclanchlan, J., and Paradis, B., J. of Nondestructive Evaluation 2, 35 (1981).CrossRefGoogle Scholar
8.Friesel, M., Materials Evaluation No. 47, 28, 842 (1989).Google Scholar
9.Scala, C. and Cusland, S., Mater. Sci. Eng. 76, 83 (1987).CrossRefGoogle Scholar
10.Daniel, I.M., Luo, J.J., Sifniotopoulos, C.G., and Chun, H.J., Rev. Prog. Quan. Nondestr. Eval. 16, 451 (1997).CrossRefGoogle Scholar
11.Guo, D., Mal, A.K., and Ono, K., J. Acoustic Emission 14, S19 (1996).Google Scholar
12.Haugse, E., Leeks, T.J., Ikegami, R., Johnson, P.E., Ziola, S.M., Doroghi, J.F., May, S., and Phelps, N., in Nondestructive Evaluation of Aging Aircraft, Airports, and Aerospace Hardware III, Bellingham, Washington, edited by Mal, A. (Proc. SPIE 3586, 1999), pp. 3240.CrossRefGoogle Scholar
13.Nam, K-W., Mal, A.K., and Wei, R.P., in Proc. Third FAA/DOD/ NASA Conference on Aging Aircraft, (Galaxy Scientific, Albuquerque, NM) Sept 20–23 (1999, in press).Google Scholar
14.Wu, J.U., Mater’s Thesis, University of California, Los Angeles, CA (1995).Google Scholar
15.McBride, S.L., Maclachlan, J.M., and Paradis, B.P., J. Nondestr. Eval. 2, 35 (1981).CrossRefGoogle Scholar
16.Carpenterand, S.H., Higgins, F.P., Metall. Trans. A 8A, 1629 (1977).CrossRefGoogle Scholar
17.Hamstad, M.A., Bianchetti, R., and Mukherjee, A.K., Eng. Fract. Mech. 9, 663 (1977).CrossRefGoogle Scholar