Optimal design and experimental study on a novel relaxor ferroelectric single crystal transducer based on face shear vibration mode.

The underwater acoustic transducer is an important component of underwater sonar detection equipment, but it has constraints in terms of wide bandwidth and small size. [011] The polarization direction and zxt-45° cut PMN-PT single crystal have the characteristics of high shear piezoelectric strain constant, high electromechanical coupling coefficient and high compliance coefficient. These advantages provide ideas for breaking through the limitations of traditional transducers in terms of wide bandwidth and small size. This paper mainly uses the face shear vibration mode of the single crystal and adopts the method of face shear vibration and longitudinal vibration coupling to broaden the working frequency band. First, the influence of structural parameters on the vibration mode and resonant frequency of each order mode is studied utilizing finite element simulation analysis. Secondly, the NSGA-Ⅱ optimization algorithm and the finite element method are used to optimize the face shear mode broadband transducer designed in this paper. Finally, a face shear single crystal longitudinal vibration transducer prototype was made and tested and analyzed. The transducer has an outer diameter of 75 mm, a length of 36 mm, an operating frequency band of 7 kHz-60 kHz, a maximum transmission voltage response of 127 dB, and an in-band transmission voltage response fluctuation of less than 4.6 dB. Therefore, the use of a new face shear mode is conducive to achieving small size, high power and broadband emission of the underwater acoustic transducer.