AN EVALUATION OF 1-3 CONNECTIVITY COMPOSITE TRANSDUCERS FOR AIR-COUPLED ULTRASONIC APPLICATIONS

A combination of theoretical modeling and experimental analysis is use d to predict and assess the performance of 1-3 composite transducers f or operation in an air-coupled environment. Specifically, finite eleme nt analysis, supported by linear systems modeling, is employed to eval uate transmission and reception characteristics over the complete volu me fraction range, for operating frequencies in the region of 500 kHz, and the;theory confirmed using novel experimental techniques. The the oretical approach is then extended to assess the influence of matching and backing on transducer sensitivity and bandwidth. Throughout, the influence of air propagation is included in the simulation approach an d highlighted where this factor is significant. The work is expected t o provide useful design guidelines for the practical ultrasonic engine er. (C) 1996 Acoustical Society of America.