Characteristics of Elastic Waves Generated by Fatigue Crack Penetration and Growth in an Aluminum Plate

  • Ahn, Seok-Hwan (College of Engineering, Pukyong National University) ;
  • Nam, Ki-Woo (College of Engineering, Pukyong National University)
  • 발행 : 2003.11.01

초록

The characteristics of elastic waves emanated from crack initiation in 6061 aluminum alloy subjected to fatigue loading are investigated through experiments. The objective of the study is to determine the differences in the properties of the signals generated from fatigue test and also to examine if the sources of the waves could be identified from the temporal and spectral characteristics of the acoustic emission (AE) waveforms. The signals are 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. Six distinct types of signals were observed. The waveforms and their power spectra were found to be dependent on the crack propagation stage and the type of fracture associated with the signals. The potential application of the approach in health monitoring of structural components using a network of surface mounted broadband sensors is discussed.

키워드

참고문헌

  1. Ando, K., Fujibayashi, S., Nam, K. W., Takahashi, M. and Ogura, N., 1987, 'The Fatigue Life and Crack Through-Thickness Behavior of a Surface-Cracked Plate (for the Case of Tensile Load),' JSME Int. J., Vol. 30, pp. 1898-1905 https://doi.org/10.1299/jsme1987.30.1898
  2. Ando, K., Matsushita, H., Fujibayashi, S. and Ogura, N., 1985, 'Separation and Fracture Toughness of Controlled Rolled Steel,' J. Society of Materials Science, Vol. 34, pp. 388-393, (in Japanese)
  3. Choi, C. Y., Kwon, J. D. and Sul, I. C., 2001, 'Application of the Leak Before Break (LBB) Concept to a Heat Exchanger in a Nuclear Power Plant,' KSME International Journal, Vol. 15, pp. 10-20
  4. Dunegan, H. L. and Harris, D. O., 1969, 'Acoustic Emission - A New Nondestructive Testing Tool,' Ultrasonics, Vol. 7, pp. 160-166 https://doi.org/10.1016/0041-624X(69)90660-X
  5. ?Elber, W., 1970, 'Fatigue Crack Closure under Cyclic Tension.' Engng. Fract. Mech., Vol. 2, pp. 37-45 https://doi.org/10.1016/0013-7944(70)90028-7
  6. Fang, D. and Berkovits, A., 1993, 'Fatigue Damage Mechanisms on the Basis of Acoustic Emission Measurements,' Novel Exper. Techniques in Fracture Mechanics, ed. by A. Shukla, AMD, Vol. 176, ASME, pp. 213-235
  7. Gilchrist, M. D., Chipalo, M. I. and Smith, R. A., 1992, 'Shape Development of Surface Defects in Tension Fatigued Finite Thickness Plates,' Int. J. Press. Piping, Vol. 49, pp. 121-137 https://doi.org/10.1016/0308-0161(92)90075-Q
  8. Guo, D., Mal, A. and Ono, K., 1996, 'Wave Theory of Acoustic Emission in Composite Laminate,' J. of Acoustic Emission, Vol. 14, pp. s19-s46
  9. Huh, N. S., Kwak, D. O., Kim, Y. J., Yu, Y. J. and Pyo, C. R., 2000, 'Effect of Nozzle on LeakBefore-Break Analysis Result of Nuclear Piping,' J. of KSME. Kor., Vol. 24, pp. 2796-2803
  10. IMCO Resolution A 328 (IX), 1975, 'Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk'
  11. Kaufman, J. G., Bucci, R. J. and Kelsey, R. A., 1980, 'Fracture Mechanics Aspects of the Structural Integrity Technology of Spherical Aluminum Containment Vessels for LNG Tankers,' ASME J. Eng. Mater. & Technology, Vol. 102, p. 303 https://doi.org/10.1115/1.3224816
  12. Kawahara, M. and Kurihara, M., 1975, 'A Preliminary Study on Surface Crack Growth in a Combined Tensile and Bending Fatigue Process,' Japan Soc. Naval Archit., Vol. 137, pp. 297-306, (in Japanese)
  13. Kim, Y. J., Huh, N. S. and Kim, Y. J., 2001, 'New Engineering Estimation Method of J-Integral and COD for Circumferential Through-Wall Cracked Pipes,' J. KSME. Kor., Vol. 25, pp. 548-553
  14. Kohn, D. H., Ducheyne, P. and Awerbuch, J., 1992, 'Acoustic Emission during Fatigue of Ti-6Al-4V: Incipient Fatigue Crack Detection Limits and Generalized Data Analysis Methodology,' J. of Materials Science, Vol. 27, pp. 3133-3142 https://doi.org/10.1007/BF01116003
  15. Liptai, R. G., Harris, D. O., Engle, R. B. and Tatro, C. A., 1971, 'Acoustic Emission Techniques in Materials Research,' Int. J. Nondestructive Testing, Vol. 3, pp. 215-275
  16. McBride, S. L., Maclachlan. J. W. and Paradis. B. P., 1981, 'Acoustic Emission and Inclusion Fracture in 7075 Aluminum Alloy,' J. Nondestructive Evaluation, Vol. 2, pp. 35-41 https://doi.org/10.1007/BF00614995
  17. Miyoshi, T. and Yoshida, Y., 1988, 'Analysis of Stress Intensity Factor Surface Cracks in Pre and Post Penetration,' Jap. Soc. Mech. Engrs, Vol. 54, pp. 1771-1777, (in Japanese) https://doi.org/10.1299/kikaia.54.1771
  18. Nam KiWoo, 1999, 'Acoustic Emission from Surface Fatigue Cracks in SS41 Steel,' Fatigue Fract. Engng. Mater. Struct., Vol. 22, No. 12, pp. 1103-1109 https://doi.org/10.1046/j.1460-2695.1999.00177.x
  19. Nam, Ki-Woo and Ahn, Seok-hwan, 2002, 'Crack opening behavior of penetrated crack under fatigue load,' KSME International Journal, Vol. 16, No. 1, pp. 24-31 https://doi.org/10.1007/BF03185152
  20. Nam, K. W., Ando, K., Ogura, N. and Matui, K., 1994, 'Fatigue Life and Penetration Behaviour of a Surface Cracked Plate under Combined Tension and Bending,' Fatigue Fract. Engng. Mater. Struct., Vol. 17, pp. 873-882 https://doi.org/10.1111/j.1460-2695.1994.tb00817.x
  21. Nam, K. W., Ando, K. and Ogura, N., 1993, 'The Effect of Specimen Size on the Behaviour of Penetrating Fatigue Cracks,' Fatigue Fract. Engng. Mater. Struct., Vol. 16, pp. 767-779 https://doi.org/10.1111/j.1460-2695.1993.tb00118.x
  22. Nam, K. W., Ando, K. and Ogura, N., 1995, 'Surface Fatigue Crack Life and Penetration Behavior of Stress Concentration Specimen,' Engng. Fract. Mech., Vol. 51, pp. 161-166 https://doi.org/10.1016/0013-7944(94)00235-A
  23. Nam, K. A. and Ajit, M., 2001, 'Characteristics of Elastic Waves Generated by Crack initiation in Aluminum Alloys under Fatigue Loading,' J. Mater. Res., Vol. 16, No. 6, pp. 1745-1751 https://doi.org/10.1557/JMR.2001.0241
  24. Sakai, T., Takashima, H., Matsumae, H. and Yajima, H., 1975, 'Studies on Nine Percent Nickel Steel for Liquefied Natural Gas Carriers,' ASTM STP, Vol. 579, pp. 205-237
  25. Wheeler, O. E., 1972, 'Spectrum Loading and Crack Growth,' J. Basic Engng., Vol. 90, pp. 181-186
  26. Wu, J.-U., 1995, 'Characterization of Acoustic Emission from Fatigue of 2024-T4 Aluminum using Pattern Recognition,' Mater's Thesis, University of California, Los Angeles, CA