Abstract:
A sandwich piezoelectric ceramic ultrasonic transducer in thickness vibration is studied. The transducer consists of the front and back metal masses,the coaxially segmented thickness polarized piezoelectric ceramic thin ring. For this kind of sandwich piezoelectric transducers, it is required that the lateral dimension of the transducer is sufficiently large compared with that of the longitudinal so that no lateral displacements in the transducer can occur (laterally clamped). The thickness vibration of piezoelectric ceramic ring is analysed and its electro-mechanical equivalent circuit is obtained. The thickness vibration of a piezoelectric ceramic stack consisting of a number of identical piezoelectric thin circular rings is analysed and its electro-mechanical equivalent circuit is also obtained using network analysis theory.Based on the frequency equation, a set of sandwich piezoelectric ceramic ultrasonic transducers are designed and manufactured, and their resonance frequencies are measured. It is shown that the measured resonance frequencies are in good agreement with the theoretical results.
