Three Dimensional Analysis of the Vibration Characteristics of Piezoelectric Discs

The piezoelectric transducer plays a paramount role in the ultrasonic non-destructive testing systems which are increasingly employed in industry. The active element in these transducers is the piezoelectric disc and its vibration characteristics govern the performance of the transducer. One dimensional theory (1D) [1], which assumes that the piezoelectric disc vibrates in the thickness direction only as shown in Fig 1, has been used for many years. However, the 1D theory cannot predict other vibration modes, which may affect the transducer behaviour in the frequency range of interest, especially for those transducers with a small diameter to thickness (D/T) ratio