Design and Fabrication of an Underwater Transducer Based on the Shear Vibration Mode and Trapezoid Transition Layer

In this study, a new kind of underwater transducer was developed using the d15 shear vibration mode of piezoelectric ceramic and a trapezoid transition layer. A series of finite element simulations were conducted to investigate how the boundary conditions of piezoelectric ceramic blocks affect the shear vibration. Finite element simulation was also used to investigate how the trapezoid transition layer transfers shear vibrations into longitudinal vibrations. A prototype of the proposed transducer was fabricated from piezoelectric vibrators working in the shear mode and a trapezoid transition layer. The underwater performance of this transducer was then tested. The results demonstrated that the transmitting voltage response, working frequency range, and bandwidth reached 163 dB (62 kHz), 37 kHz-68 kHz, and 31 kHz when the radiating area of the transducer was 120 mm × 240 mm. The transmitting voltage response caused by the d15 shear vibration mode reached 160.9 dB at 89 kHz.