본문 바로가기
KERD
논문KCI 등재

램파의 분산성과 파 반사가 시간반전과정에 미치는 영향의 이해

Understanding the Effects of the Dispersion and Reflection of Lamb Waves ona Time Reversal Process

0

조회

0

다운로드

1

인용

0

참고문헌

키워드

초록

이 연구에서는 얇은 판형구조물의 손상탐지에 널리 사용되어오는 램파에 시간반전(time reversal)개념의 적용성을 이론적으로 규명한다. 고전적 시간반전 음향학에 의하면, 센서에서의 출력신호를 시간영역에서 반전 후 재입사시켜 원래의 가진점으로 돌려보내면, 그 가진점에서 원래 입력신호가 복원된다. 그러나 램파에 시간반전과정을 적용하게 되면 램파 고유의 분산성과 판 경계에서의 파 반사로 인해 시간반전성이 복잡한 양상을 띠게 된다. 이러한 램파의 시간반전성을 보다 잘 이해하기 위해 이 연구에서는 램파의 시간반전과정을 이론적으로 규명한다. 특히, 램파의 내부모드분산, 다중모드분산, 그리고 판 경계면에서의 램파의 반사가 시간반전성에 미치는 영향을 정식화하였다. 간단한 수치예제를 통해 이 연구에서 제시된 이론적 발견들의 타당성을 검증한다.

Abstract

This study investigates the applicability of the time reversal concept in modern acoustics to the Lamb waves, which have been widely studied for defect detection in plate-like structures. According to conventional time reversal acoustics, an input signal can be reconstructed at an excitation point if an output signal recorded at another point is reversed in the time domain and emitted back to the original source point. However, the application of a time reversal process(TRP) to Lamb wave propagations is complicated due to velocity and amplitude dispersion characteristics of Lamb waves and reflections from the boundaries of a structure. In this study, theoretical investigations are presented to better understand the time reversibility of Lamb waves. In particular, the effects of within-mode dispersion, multimode dispersion, amplitude dispersion, and reflections from boundaries on the TRP are theoretically formulated. Simple numerical case studies are conducted to validate the theoretical findings of this study.

참고문헌 (34)

  1. Fink, M., "Time-reversed acoustics", Scientific American, 281(5), pp.91~97 (1999)
  2. Fink, M., "Acoustic time-reversal mirrors", Inverse Problems, 17, pp.R1~R38 (2001)
  3. Fung, Y.C., "Foundation of Solid Mechanics", pp.525~ (1965), Prentice-Hall, INC.
  4. "Embedded NDE with Piezoelectric Wafer Active Sensors in Aerospace Applications, Journal of Materials"[URL]
  5. Giurgiutiu, V., "Tuned Lamb wave excitation and detection with piezoelectric wafer active sensors for structural health monitoring", Journal of Intelligent Materials and Structures, 16(4), pp.291~305 (2005)
  6. Ing, R. K., "Time recompression of dispersive Lamb waves using a time reversal mirror: Application to flaw detection in thin plates", 1996 IEEE Ultrasonics Symposium, 통권 : 1, pp.659~663 (1996)
  7. Ing, R. K., "Time-reversed Lamb waves. IEEE Transactions on Ultrasonics", Ferroelectrics and Frequency control, 45(4), pp.1032~1043 (1998)
  8. Ing, R. K., "Self-focusing and time recompression of Lamb waves using a time reversal mirror", Journal of the Acoustical Society of America, 104(2), pp.801~807 (1998)
  9. Johnson, E. A., "Phase IIASC-ASCE structural health monitoring benchmark problem using simulated data", Journal of Engineering Mechanics, 130, pp.3~15 (2004), ASCE
  10. Kazakov, V. V., "Sensitive imaging of an elastic nonlinear wave- scattering source in a solid", Applied Physics Letters, 81(4), pp.646~648 (2002)
  11. Kessler, S. S., "Experimental application of optimized Lamb wave actuating", sensing patches for health monitoring of composite structures, 2003, 429~436[DOI]
  12. Kim, S. B., "Application of time- reversal guided waves to field bridge testing for baseline-free damage diagnosis", Proceedings of SPIE Conference on Smart Structures and NDE (2006)
  13. Kim, S.B., "Instantaneous reference- free crack detection based on polarization characteristics of piezoelectric materials", Smart Materials and Structures, 16, pp.2375~2387 (2007)
  14. Kim, S.B., "Application of a Time Reversal Process for Baseline-Free Monitoring of a Bridge Steel Girder", Proceedings of the 5th International Workshop on Structural Health Monitoring (2005)
  15. Mindlin, R.D., "Influence of rotatory inertia and shear on flexural motions of isotropic, elastic plates", Journal of Applied Mechanics, 18, pp.31~38 (1951)
  16. Moulin, E., "Piezoelectric transducer embedded in a composite plate: application to Lamb wave generation", Journal of Applied Physics, 82(5), pp.2049~2055 (1997)
  17. Paget, C.A., "Damage assessment in composites by Lamb waves and wavelet coefficients", Smart Materials and Structures, 12(3), pp.393~402 (2003)
  18. Park, H.W., "Time reversal active sensing for health monitoring of a composite plate", Journal of Sound and Vibration, 302(1), pp.50~66 (2007)
  19. "Piezo Systems, Inc."[URL]
  20. Prada, C., "Separation of interfering acoustic scattered signals using the invariants of the time-reversal operator, Application to Lamb waves characterization", Journal of the Acoustical Society of America, 104(2), pp.801~807 (1998)
  21. Raghavan, A., "Review of Guided- wave Structural Health Monitoring", The Shock and Vibration Digest, 39(2), pp.91~114 (2007)
  22. Rose, J.L., "Ultrasonic Waves in Solid Media", pp.472~ (1999), Cambridge University Press
  23. Scalea, F.L.D., "Propagation of ultrasonic guided waves in lap-shear adhesive joints: Case of incident A0 Lamb wave", Journal of the Acoustical Society of America, 115(1), pp.146~156 (2004)
  24. "Smart Material Corp."[URL]
  25. Sohn, H., "Effects of Environmental and Operational Variability on Structural Health Monitoring", a Special Issue of Philosophical Transactions of the Royal Society on Structural Health Monitoring, 365(1851), pp.539~560 (2007)
  26. A Review of Structural Health Monitoring Literature: 1996-2001, "Sohn, H.", Los Alamos National Laboratory Report, 301~, pp.LA-13976-MS (2003)
  27. Sohn, H., "Reference-free damage classification based on cluster analysis", Aided Civil and Infrastructure Engineering, 23, pp.324~338 (2008)
  28. Sohn, H., "Wavelet-Based Active Sensing for Delamination Detection in Composite Structures", Smart Materials and Structures, 13, pp.153~160 (2004)
  29. Sohn, H., "Damage detection in composite plates by using an enhanced time reversal method", Journal of Aerospace Engineering, 20(7), pp.141~151 (2007), ASCE
  30. Sohn, H., "Combination of a time reversal process and a consecutive outlier analysis for baseline-free damage diagnosis", Journal of Intelligent Materials and Smart Structures, 18(4), pp.335~346 (2007)
  31. Su, Z.Q., "Guided Lamb waves for identification of damage in composite structures: A review", Journal of sound and vibration, 295(3), pp.753~780 (2006)
  32. Viktorov, I.A., "Rayleigh and Lamb Waves: Physical Theory and Applications" (1967), Plenum Press
  33. Wang, C.H., "A computerized time-reversal method for structural health monitoring", Proceedings of SPIE Conference on Smart Structures and NDE (2003)
  34. Wilcox, P., "Lamb and SH wave transducer arrays for the inspection of large areas of thick plates, in: Review of Progress in Quantitative NDE 19B", pp.1049~1056 (2000), AIP

이 간행물의 다른 논문 (11건)