Quantitative Materials Characterization of Elastic Plates Using Air-Coupled Leaky Lamb Waves

  • D. E. Chimenti
  • A. Safaeinili
  • O. I. Lobkis


The signal-to-noise penalty of air or gas-coupled ultrasonics has so far limited its application principally to feasibility demonstration experiments and qualitative assessments of material condition [1–3]. In most cases to date, use of air-coupled ultrasound to estimate material properties has been performed by observing the phase-matched transmitted signal amplitude and correlating this occurrence with the plate wavespeed. While this approach has approximate validity, other experimental conditions, including geometry and frequency, as we have shown [4], can significantly alter the estimate of material properties made only on the basis of phase-matched amplitude extrema. In addition, since the acoustic impedance mismatch is so large in air-coupled measurements, material damping plays a greatly enhanced role in determining the nature of the transmitted or reflected field.


Transmission Coefficient Lamb Wave Transmission Function Acoustic Beam Plexiglas Plate 
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Copyright information

© Plenum Press, New York 1996

Authors and Affiliations

  • D. E. Chimenti
    • 1
  • A. Safaeinili
    • 2
  • O. I. Lobkis
    • 3
  1. 1.Aero Engrg & Engrg Mechanics DeptIowa State UniversityAmesUSA
  2. 2.Rockwell International Science CenterThousand OaksUSA
  3. 3.Center for NDEIowa State UniversityAmesUSA

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