Finite aperture influence on energy concentration, frequency shift, and signal enhancement, for acoustic transmission in the negative group velocity region of the S<inf>1</inf> leaky Lamb mode


Acoustic beam diffraction phenomena for normal beam incidence to a viscoelastic plate, such as resonance frequency downshift, beam narrowing, and axial signal enhancement near certain leaky Lamb modes, have been demonstrated in recent years, as compared to plane-wave analyses. A close correlation between these phenomena and apparantly different guided-wave… (More)


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