Journal of Ocean Engineering and Technology (한국해양공학회지)

Korean Society of Ocean Engineers (한국해양공학회)
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Frequency Characteristics of Acoustic Emission Signal from Fatigue Crack Propagation in 5083 Aluminum by Joint Time-Frequency Analysis Method

시간-주파수 해석법에 의한 5083 알루미늄의 피로균열 진전에 의할 음향방출 신호의 주파수특성

  • NAM KI-WOO (Dept. of Materials Science and Engineering, Pukyong National University) ;
  • LEE KUN-CHAN (Graduate School, Pukyong National University)
  • Published : 2003.06.01
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Abstract

Acoustic emission (AE) signals, emanated during local failure of aluminum alloys, have been the subject of numerous investigations. It is well known that the characteristics of AE are strongly influenced by the previous thermal and mechanical treatment of the sample. Possible sources of AE during deformation have been suggested as the avalanche motion of dislocations, fracture of brittle particles, and debonding of these particles from the alloy matrix. The goal of the present study is to determine if AE occurring as the result of fatigue crack propagation could be evaluated by the joint time-frequency analysis method, short time Fourier transform (STFT), and Wigner-Ville distribution (WVD). The time-frequency analysis methods can be used to analyze non-stationary AE more effectively than conventional techniques. STFT is more effective than WVD in analyzing AE signals. Noise and frequency characteristics of crack openings and closures could be separated using STFT. The influence of various fatigue parameters on the frequency characteristics of AE signals was investigated.

Keywords

References

  1. 남기우, 김선진, 이건찬, 오정환, 오세규, 이주석 (1997). "표면 균열재의 피로균열관통거동에 따른 어코스틱에미션", 한국해양공학회지, 제11권, 제3호, pp 29-38
  2. 남기우, 문창권 (2002). "CFRP적층 형태에 따른 파괴시 음향방출 신호특성", 한국해양공학회지, 제16권, 제2호, pp 67-71
  3. 남기우, 박소순, 안석환 (2003). "STS316L용접재의 표면파에 의한 잔류응력 측정과 균열진전시의 음향방출특성", 한국해양공학회지, 제17권, 제1호, pp 47-54
  4. 이건찬, 오정환, 남기우, 이주석 (1999). "열화된 SUS316강의시간-주파수 해석에 의한 비파괴평가", 비파괴검사학회지, 제19권, 제4호, pp 270-276
  5. Abbate, A., Koay, J., Frankel, J., Schroeder, S.S. and Pankaj, D. (1997). "Signal Detection and Noise Suppression Using a Wavelet Transform Signal Processor: Application to Ultrasonic Flaw Detection", IEEE Transaction on Ultrasonics, Ferroelectrics, and Frequency Control, Vol 44, pp 14-26 https://doi.org/10.1109/58.585186
  6. 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
  7. Jin, X.M., Malik, M.A. and Saniie, J. (1996). " Singular Value Decomposition of Wigner Distribution for Time Frequency Representation of Ultrasonic Echoes", Review of Progress in Quantitative Nondestructive Evaluation, Vol 15, pp 762-772
  8. Kawashima, K. and Fujii, I. (1993). "Comparison among Several Digital Methods of Measuring Time-of Flight of Ultrasonic Waves in Solids", JSME, Vol 59, pp 286-291
  9. Lee, C.S., Rhyme, Y.M., Park, K.J. and Chang, Y.W. (1994). "Fatigue Crack Propagation and Crack Closure in Al-Li 890 Alloy", Proc. of the Eighth Conference on Mechanical Behaviors of Materials, Vol 10, pp 169-180
  10. Musha, T and Kawaura, J. (1991). "Wigner Distribution Function and its Application for the Ultrasonic Nondestructive Evaluation", JSNT, Vol 40, pp 587-591
  11. Malik, M.A., Jin, X.M. and Saniie, J. (1996). "Joint Time-Frequency Processing of Ultrasonic Signals", Review of Progress in Quantitative Nondestructive Evaluation, Vol 15, pp 2089-2096