指向性弯张换能器

Directional flextensional transducer

针对指向性弯张换能器双振源驱动的幅度相位调控的复杂性问题,本文提出一种指向性弯张换能器结构,采用径向振动PZT圆环驱动一凸一凹弯曲振动球冠帽复合结构实现指向性发射。通过一对凸凹振动臂的不等幅振动激发单极子与偶极子的工作模态,叠加形成指向性。换能器拥有较小的几何尺寸:∅100 mm×37 mm。利用有限元方法进行换能器结构设计和振动辐射特性分析,在3675 Hz频率处最大发射电压响应为119.8 dB、最大声源级可达180 dB。在3400 Hz频率处辐射指向性前后最大声压比为-27.4 dB,形成“心形”指向性波束。在3200~4000 Hz频带内发射电压响应起伏约为4 dB、频带内辐射指向性前后声压比超过-5 dB。

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 3675 Hz.A cardioid directional beam forms at 3400 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 3200 Hz to 4000 Hz.