Directional flextensional transducer

To solve the complex problem of regulating the amplitude and phase of the double driver in the directional flextensional transducer, in this paper we propose a new structure for this transducer. The directivity of the directional flextensional transducer is realized by a composite structure of convex and concave flexural spherical caps driven by a radial vibration PZT ring. Its working principle of the transducer is that it achieves directional motion by the superposition of the monopole and dipole modes stimulated by an unequal amplitude vibration from a pair of convex-concave arms. The transducer is small in size, i.e., 37 mm in height and 100 mm in diameter. We used the finite element method to design the transducer structure and then we analyzed its vibration and radiation characteristics. The maximum transmitting voltage response is 119.8 dB and the maximum source level can reach 180 dB at a frequency of 3 675 Hz. A cardioid directional beam forms at 3 400 Hz with a lowest radiation-directivity front and back sound pressure ratio of -27.4 dB. The radiation-directivity front and back sound pressure ratio exceeds -5 dB and the transmitting voltage response of the transducer fluctuates approximately 4 dB in a frequency range from 3 200 Hz to 4 000 Hz. Copyright ©2020 Journal of Harbin Engineering University.