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Determining Mechanical Properties of Cardboard from Photoacoustic Lamb Wave Transmission Data

  • Markku Oksanen
  • Jyrki Stor-Pellinen
  • Mauri Luukkala
Chapter

Abstract

Laser-generated transient Lamb waves have been proven to be a useful tool for determining thin plate thickness and elastic constants. The measurement relies on the wide range of frequencies generated by the thermoelastic or ablation laser source [1]. The dispersion relation of the lowest Lamb-wave modes can be determined using established signal processing techniques. Usually the Lamb-wave packet propagating on a plate is observed using for example a) a contact “wedge” transducer, b) by observing the leakage of energy in directions where the k-matching condition is fulfilled or c) an interferometer, d) with near-field microphones with spatial periodicity on the sensitive surface to pick a particular wavelength [2,3,4,5]. The last three of these methods are non-contacting and therefore attractive for practical applications.

Keywords

Phase Velocity Lamb Wave Typical Waveform Spatial Periodicity Lamb Wave Generation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    R.J. Dewhurst, C. Edwards, A.D.W. McKie, and S.B. Palmer, Appl. Phys. Lett. 51 (14), 5 October 1987.Google Scholar
  2. 2.
    M. Luukkala, P. Meriläinen, Metal plate testing using airborne ultrasound Ultrasonics, IPC Science and Technology Press Ltd, Guilford, England, UK September, 1973.Google Scholar
  3. 3.
    I.A. Viktorov, Rayleigh and Lamb Waves; Physical Theory and Applications, Plenum Press, New York (1967).Google Scholar
  4. 4.
    C.B. Scruby and L.E. Drain, Laser Acoustics; Tecniques and Applications, Adam Hilger, Bristol 1990.Google Scholar
  5. 5.
    C. Edwards, A. Al-Kassim and S.B. Palmer, Rev. of Progress in Quantitative Nondestuctive Evaluation, Vol 12, Plenum Press, New York, 1993.Google Scholar

Copyright information

© Plenum Press, New York 1995

Authors and Affiliations

  • Markku Oksanen
    • 1
  • Jyrki Stor-Pellinen
    • 1
  • Mauri Luukkala
    • 1
  1. 1.Department of PhysicsUniversity of HelsinkiHelsinkiFinland

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