Journal of the Korean Society for Nondestructive Testing (비파괴검사학회지)

The Korean Society for Nondestructive Testing (한국비파괴검사학회)
권호 표지

Quantitative Estimation of Transmitted and Reflected Lamb Waves at Discontinuity

불연속면에서 램파의 반사와 투과에 대한 정량적 추정

  • Lim, Hyung-Jin (The Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology) ;
  • Sohn, Hoon (The Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology)
  • 임형진 (한국과학기술원 건설 및 환경공학과) ;
  • 손훈 (한국과학기술원 건설 및 환경공학과)
  • Received : 2010.01.22
  • Accepted : 2010.08.06
  • Published : 2010.08.30
Download PDF
⟨ Previous Next ⟩

Abstract

For the application of Lamb wave to structural health monitoring(SHM), understanding its physical characteristic and interaction between Lamb wave and defect of the host structure is an important issue. In this study, reflected, transmitted and mode converted Lamb waves at discontinuity of a plate structure were simulated and the amplitude ratios are calculated theoretically using Modal decomposition method. The predicted results were verified comparing with finite element method(FEM) and experimental results simulating attached PZTs. The result shows that the theoretical prediction is close to the FEM and the experimental verification. Moreover, quantitative estimation method was suggested using amplitude ratio of Lamb wave at discontinuity.

램파를 구조물 안전진단(structural health monitoring, 이하 SMH) 기법에 효과적으로 적용하기 위해서 구조물의 손상과 램파간의 물리적 특성 및 상호관계를 정확히 이해하는 것이 중요하다. 본 연구에서는 modal decomposition 방법을 이용하여 비대칭 불연속면에서 램파의 투과와 반사, 모드 변이를 모사하고, 그 진폭 비율을 불연속면의 깊이에 따라 예측하였다. 또한 이론적으로 예측된 결과를 압전센서(PZT)를 모사한 유한요소법(FEM) 모델과 실험을 통해 검증하였다. 그 결과, modal decomposition 방법을 이용한 이론적 예측이 압전센서를 이용한 유한요소 해석 및 실험 결과와 근접한 것을 확인하였으며, 불연속면의 깊이에 따른 램파의 반사와 투과, 모드 변이의 양을 이용하여 손상의 크기를 정량적으로 측정할 수 있는 방법을 제안하였다.

Keywords

Acknowledgement

Supported by : 한국연구재단(NRF)

References

  1. B. Morvan, N. Wilkie-ChancelIier, H. Duflo, A. Tinel and J. Duclos, "Lamb wave reflection at the edge of a plate," J. Acoust. Soc. Am., Vol. 113, No.3, pp. 1417-1425 (2003) https://doi.org/10.1121/1.1539521
  2. F. Benmeddour, S. Grondel, J. Assaad and E. Moulin, "Study of fundamental Lamb modes interaction with symmetrical notches," NDT&E International, Vol. 41, pp. 1-9 (2008) https://doi.org/10.1016/j.ndteint.2007.07.001
  3. F. Benmeddour, S. Grondel, J. Assaad and E. Moulin, "Study of fundamental Lamb modes interaction with symmetrical notches," NDT&E International, Vol. 41, pp. 330-340 (2008) https://doi.org/10.1016/j.ndteint.2008.01.004
  4. M. Castaings, E. L. Clezio and B. Hosten, "Modal decomposition method for modeling the interaction of Lamb waves with cracks," J. Acoust. Soc. Am, Vol. 112, No. 6, pp. 2567-2582 (2002) https://doi.org/10.1121/1.1500756
  5. H. J. Jeong, T. H. Kim, S. S. Lee and Y. G. Kim, "Finite element modeling of wall thinning defects: applications to Lamb wave generation and interaction," Journal of the Korean Society for Nondestructive Testing, Vol. 28, No.2, pp. 199-204 (2008)
  6. H. J. Jeong and M. C. Park, "Finite element simulation of laser-generated ultrasound and interaction with surface breaking cracks," Journal of the Korean Society for Nondestructive Testing, Vol. 24, No.3, pp . 259-267 (2004)
  7. V. Giurgiutiu, Structural Health Monitoring with Piezoelectric Wafer Active Sensor, Elsevier Inc. (2008)
  8. J. L. Rose, Ultrasonic Waves in Solid Media, Cambridge Univ. Press (1999)
  9. Y. Cho, "Estimation of ultrasonic guided wave mode conversion in a plate with thickness variation," IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 47, No.3, pp. 591-603 (2000) https://doi.org/10.1109/58.842046
  10. P. Kudela and W. Ostachowicsz, "A multilayer composite beam and plate elements: Reflected of Lamb waves at delamination," Mechanics of Advanced Materials and Structures, Vol. 16, No.3, pp. 174-187 (2009) https://doi.org/10.1080/15376490902746749
  11. S. B. Kim and H. Sohn, "Instantaneous reference-free crack detection based on polarization characteristics of piezoelectric materials," Smart Materials and Structures, Vol. 16, pp. 2375-2387 (2007) https://doi.org/10.1088/0964-1726/16/6/042