Analysis of acousto-ultrasonic characteristics for an isotropic thin plate

For the purposeof-understanding and improving the acousto-ultrasonic (AU) t echnique, the AU characteristics for an isotropic plate is investigated in this paper. Unlike the previous wave tracing method, a spectral analysis ap proach is presented, which can take into account-the effects of the transdu cers' characteristics. Using this approach and introducing the point source /point receiver assumption, the input-output frequency spectrum relationshi ps for the cases of one transmitter/one receiver and one transmitter/multip le receivers coupled to an:isotropic thin plate are expressed in explicit f orms. Based on this, a wave scattering parameter to bridge two different se nsing types of the receiving transducers is presented, and a new type stres s wave parameter for the AU technique is developed, which eliminates the in fluence of the complex mechanic-electron transduction characteristics of th e receivers and also separates to some extent the effects of Some other ext ernal factors such as transducer masses and locations. Finally, some numeri cal simulation are carried out and conclusions drawn concerning the AU tech nique. (C) 1999 Acoustical Society of America. [S0001-4966(99)03906-5].