Journal of the Korean Society for Nondestructive Testing (비파괴검사학회지)

The Korean Society for Nondestructive Testing (한국비파괴검사학회)
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Reconstruction of Dispersive Lamb Waves in Time Plates Using a Time Reversal Method

  • Jeong, Hyun-Jo (Division of Mechanical and Automotive Engineering, Wonkwang University)
  • Published : 2008.02.28
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Abstract

Time reversal (TR) of nondispersive body waves has been used in many applications including ultrasonic NDE. However, the study of the TR method for Lamb waves on thin structures is not well established. In this paper, the full reconstruction of the input signal is investigated for dispersive Lamb waves by introducing a time reversal operator based on the Mindlin plate theory. A broadband and a narrowband input waveform are employed to reconstruct the $A_0$ mode of Lamb wave propagations. Due to the frequency dependence of the TR process of Lamb waves, different frequency components of the broadband excitation are scaled differently during the time reversal process and the original input signal cannot be fully restored. This is the primary reason for using a narrowband excitation to enhance the flaw detectability.

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References

  1. Draeger, C. Cassereau, D. and Fink, M. (1997) Acoustic Time Reversal in Solids, J. Acoust. Soc. Am. Vol. 102, No. 3, pp. 1289-1295 https://doi.org/10.1121/1.420094
  2. Fink, M. (1999) Time-Reversed Acoustics, Scientific American, Vol. 281, No. 5, pp. 91-97 https://doi.org/10.1038/scientificamerican1199-91
  3. Fink, M. and Prada, C. (2001) Acoustic Time-Reversal Mirrors, Inverse Problems Vol. 17, R1-R38 https://doi.org/10.1088/0266-5611/17/1/301
  4. Ing, R. K. and Fink, M. (1998) Self-Focusing and Time Recompression of Lamb Waves Using a Time Reversal Mirror, Ultrasonics Vol. 36, pp. 179-186 https://doi.org/10.1016/S0041-624X(97)00100-5
  5. Ing, R. K. and Fink, M. (1998) Time-Reversed Lamb Waves, IEEE UFFC Vol. 45, pp. 1032- 1043 https://doi.org/10.1109/58.710586
  6. Park, H. W., Sohn, H., Law K. H. and Farrar, C. R. (2007) Time Reversal Active Sensing for Health Monitoring of a Composite Plate, J. Sound and Vib. Vol. 302, pp. 50-66 https://doi.org/10.1016/j.jsv.2006.10.044
  7. Rose, L. R. F. and Wang, C. H. (2004) Mindlin Plate Theory for Damage Detection, Source Locations, J. Acoust. Soc. Am Vol. 116, No. 1, pp. 154-171 https://doi.org/10.1121/1.1739482
  8. Wang, C. H., Rose, J. T. and Chang, F.-K. (2003) A Computerized Time-Reversal Method for Structural Health Monitoring, Proc. SPIE Conference on NDE and Health Monitoring of Aerospace Materials and Composites II Vol. 5046, pp. 48-58