ACOUSTOULTRASONIC CHARACTERISTICS FOR CONTACT-TYPE TRANSDUCERS COUPLED TO TIMOSHENKO BEAM

Acousto-ultrasonic input-output characteristics for transmitting and r eceiving contact-type transducers coupled to a Timoshenko beam are con sidered. Through introducing some simplifying assumptions for the tran sducers, an analytical method that can deal with all wave processes in volved with the system, i.e., wave generation, wave propagation, and w ave reception, is developed. Using this method, the spectral response of the normal contact pressure sensed by the receiving transducer, due to an arbitrary input pulse excited by the transmitting transducer, i s expressed in the form of explicit physical interpretations. The time history of the contact pressure output for the receiver is obtained b y using the fast Fourier transform technique. Finally, based on the an alytical results obtained and large amounts of numerical calculation, the input-output characteristics of the system are discussed. The anal ysis method can be easily extended to some more general cases, such as those of composite plates and multiple transducers.