径向夹心式复合换能器径向振动特性研究

Study on the radial vibration Characteristic of a radial composite sandwiched transducer

研究了一种新型径向夹心式复合换能器的径向振动。该换能器由径向极化的压电陶瓷圆环及内外金属环构成。获得了压电环及金属环的机电等效电路,根据机械边界条件,得到换能器的三端机电等效电路,并求得换能器的频率方程。得到共振频率反共振频率以及有等效机电耦合系数与复合换能器几何尺寸间的理论关系。同时用有限元方法对换能器的径向振动进行模拟仿真,并实验测量了换能器的共振与反共振频率。结果表明,理论计算、模拟仿真以及实验测量结果符合较好。

A new type of radially sandwiched composite piezoelectric transducers is developed and its radial vibration is studied. The transducer is composed of two metal rings and a radially polarized piezoelectric ring which is sandwiched between the inner and outer metal rings. The electromechanical equivalent circuits of the piezoelectric and metal rings in radial vibration are introduced. Based on the mechanical boundary conditions,a three-port equivalent circuit for the transducer is obtained and the frequency equation is given. The theoretical relationship of the resonance / anti-resonance frequency and the effective electromechanical coupling coefficient with the geometrical dimensions of the composite transducer is analyzed. The radial vibration of the transducer is simulated by using finite element method. The resonance and anti-resonance frequencies of the composite transducers are measured. It is shown that the analytical,numerical and experimental resonance and anti-resonance transducers are in good agreement with each other.