Journal or Book Title
Journal of the Acoustical Society of America
This paper presents and demonstrates a noncontact method for measuring the Lamb wave dispersion spectrum of a plate. Noncontact air-coupled source and receive transducers are used with line-focus mirrors and 50–700 kHz broadband apparatus for simultaneous measurement over a broad spectrum of refractive angles and multiple guided modes. Broadband, wide-angle wave forms are measured as a function of position. The Fourier transform of these wave forms from the t – x domain to the v – k domain gives an approximate spectrum of the dispersion relation. We measure the dispersion spectra of Lucite™, aluminum, balsa wood, and a carbon fiber epoxy laminate, and show that the measured spectra agree well with the dispersion relation calculated from Lamb wave theory.
Acoustical Society of America
Holland, Stephen D.; Teles, Sorin V.; and Chimenti, Dale E., "Air-coupled, focused ultrasonic dispersion spectrum reconstruction in plates" (2004). Aerospace Engineering Publications. 5.