Acousto-ultrasonic characteristics for contact-type transducers coupled to a composite beam

摘要

Acousto-ultrasonic technique is finding an increased usage among the nondestructive evaluation of composite materials. In this paper the acousto-ultrasonic characteristics for transmitting and receiving contact-type transducers coupled to acomposite beam are considered. Through introducing some simplifying assumptions for the transducers, an analytical method which can deal with all wave processes involved with the system, i.e. wave generation, wave propagation and wave reception, isdeveloped. Using this method, the spectral response of the normal contact stress sensed by the receiving transducer, due to an arbitrary input pulse excited by the transmitting transducer, is expressed in the form of explicit physical interpretations. The time history of thc contact stress output for the receiver is obtained by using the Fast Fourier Transform (FFT) technique. Finally, from some numerical results the acousto-ultrasonic characteristics arc discussed.