Optimization of a sandwich longitudinal vibration transducer with a large radiation surface based on hole structure of near- periodic phononic crystal

The existence of radial vibration in a large-dimension sandwich longitudinal vibration piezoelectric ceramic transducer will reduce the longitudinal radiated sound power and shorten the service life of the transducer, which seriously affects its performance and reliability. To reduce the strong coupling between longitudinal and radial vibration, ensure high longitudinal working efficiency and reliability, and overcome the disadvantages of narrow working bandwidth, poor uniformity of amplitude distribution, and small displacement amplitude, the large-dimension sandwich longitudinal vibration piezoelectric ceramic transducer is optimized through machining several periodic holes on the front cover plate of the transducer to form a multi-point deformation defect structure. In this study, the simulation software is used to simulate and analyze the performance index of the optimized transducer, and the optimization effect is verified through experiments. The results show that the large-dimension piezoelectric ceramic transducer based on a multi-point deformation defect near-periodic phononic crystal structure has a single longitudinal vibration mode, which can effectively improve the displacement amplitude and amplitude distribution uniformity of the radiation surface of a large -dimension transducer and broaden the transducer's working bandwidth.