Study on the Performance of Concave Flextensional Transducer Based on Finite Element Method

Cymbal transducer, as the fifth-generation flextensional transducer designed with a "sandwich" structure, is widely applied in underwater acoustics transducers, accelerometers and ultrasonic medical devices because of its advantages including high sensitivity, simple structure, easy fabrication, low cost, and convenient batch production. With such characteristics as small size and light weight, it can also better achieve lower frequencies, which is difficult to realize with traditional transducers. However, the Cymbal transducers of such a traditional design can no longer meet actual needs since they feature low-pressure resistance and narrow bandwidth when the underwater target acquisition evolves toward large water depth, wide frequency band, and low frequency. Based on the traditional Cymbal structure, this paper introduces a design of concave Cymbal transducer structure, which adopts a hollow piezoelectric ceramic ring and an inverted metal end cap. The proposed design can enhance the pressure resistance of the Cymbal transducer, expand its frequency bandwidth and improve its electromechanical characteristics. It is demonstrated that the finite element method can be used with a two-dimensional 1/2 axisymmetric model to analyze and identify the changes in the structural dimensions of the piezoelectric ceramic ring and the metal end cap. On this basis, this paper generalizes how such changes affect the electromechanical characteristics of the concave Cymbal transducer such as resonance frequency, bandwidth and quality factor, in a bid to provide a reference for industry personnel.