Jia Longyang, Zhang Guangbing, Zhang Xiaofeng, Yao Yu, Lin Shuyu
College of Physics and Information Technology, Shanxi Normal University, State Key Laboratory of Shaanxi Province, Xi'an 710119, China.
College of Physics and Information Technology, Shanxi Normal University, State Key Laboratory of Shaanxi Province, Xi'an 710119, China.
Ultrasonics. 2017 Feb;74:204-210. doi: 10.1016/j.ultras.2016.10.013. Epub 2016 Oct 31.
In this work, we proposed an effective way to fabricate a tangentially polarized composite cylindrical transducer with high electro-mechanical coupling coefficient (EMCC) by radially connecting an inner tangential polarized piezoelectric tube with an outer metal ring. The resonance frequency and EMCC of the proposed transducer are calculated according to frequency equations, which are obtained from the equivalent circuit of the transducer, and the results indicate that EMCC of the tangentially polarized cylindrical transducer is much higher than that of the cylindrical transducer polarized in radial direction. Furthermore, the Finite Element Method (FEM) model of the transducer is established and used for numerical simulation of the vibration models and the optimum configuration parameters. On the basis of those theoretical results, serials of prototype transducers are manufactured with an inner tangential polarized piezoelectric tube connecting with different outer metal cylindrical shells. The admittance characteristics of the fabricated transducers measured by Impedance Analyzer clearly demonstrate that the resonance frequencies of the transducers are in good agreement with those of simulation results, and the effective EMCC of transducers varies with the material of metal cylindrical shell, in which aluminum metal shell possesses the highest EMCC.
在这项工作中，我们提出了一种有效的方法来制造具有高机电耦合系数（EMCC）的切向极化复合圆柱换能器，该方法是通过将一个内部切向极化的压电管与一个外部金属环径向连接来实现的。根据从换能器等效电路得出的频率方程，计算了所提出换能器的共振频率和EMCC，结果表明，切向极化圆柱换能器的EMCC远高于径向极化圆柱换能器的EMCC。此外，建立了换能器的有限元方法（FEM）模型，并用于振动模型和最佳配置参数的数值模拟。基于这些理论结果，制造了一系列原型换能器，其中内部切向极化压电管与不同的外部金属圆柱壳相连。通过阻抗分析仪测量所制造换能器的导纳特性，结果清楚地表明，换能器的共振频率与模拟结果高度吻合，并且换能器的有效EMCC随金属圆柱壳的材料而变化，其中铝金属壳具有最高的EMCC。
