CHARACTERIZATION OF TRANSFER-FUNCTIONS FOR PIEZOCERAMIC AND CONVENTIONAL TRANSDUCERS

This paper analytically derives the transfer functions for piezocerami c and conventional transducers and characterizes their relationships i n terms of frequency response function (FRF) and modal parameters such as natural frequencies, damping ratios, and mode shapes. The FRFs bet ween accelerometer/point force actuator. accelerometer/PZT actuator, P VDF sensor/point force actuator, and PVDF sensor/PZT actuator are dete rmined, respectively. Those FRFs are expressed in conventional modal m odel format which can clearly get insight of physical meaning of modal parameters. In particular, the mode shapes of accelerometer, point fo rce actuator, PVDF sensor, and PZT actuator are identified and are pro portional to the displacement mode shapes. The point and transfer FRFs are then studied re, characterize their properties for either pair of transducer applications. This work leads to the basis for active stru ctural vibration and acoustic control and also draws on ideas for appl ications of smart structural testing to system identification and diag nosis.