复合圆环弯曲振动四极子模态分析

针对压电圆环弯曲振动机电转换性能较差的问题,提出了一种复合圆环弯曲振动换能器,它由一个径向极化的压电陶瓷内圆环和一个金属外圆环复合而成。基于能量原理推导得到了复合圆环弯曲振动的谐振频率和有效机电耦合系数,探讨了弯曲振动四极子模态特性与其结构尺寸间的关系。当压电圆环尺寸不变时,随外侧金属圆环壁厚增加,复合圆环弯曲振动四极子模态谐振频率上升,有效机电耦合系数迅速上升到极大值后缓慢下降。最后,设计制作了圆环换能器并对其谐振频率和有效机电耦合系数进行了实验测试,测试结果与解析结果和数值模拟结果吻合得较好。 

Flexural vibration for a radially polarized piezoelectric composite ring transducer

A type of radial composite piezoelectric ceramic ring transducer in flexural vibration is presented and its flexural vibration is studied.The transducer is composed of a radially polarized piezoelectric ceramic ring and a metal ring.Using the energy method,the resonance frequency and the effective electromechanical coupling coefficient are obtained.The impacts of the geometries of the composite ring on its performance are also investigated.As the thickness of metal ring increases,the resonance frequency also increases,while the effective electromechanical coupling coefficient has a maximum value.Then the finite element analysis is carried out and two transducers are assembled and measured.It is shown that the theoretical predictions agree well with the simulated and experimental results.The composite circular ring transducer has evident advantages compared with pure piezoelectric ceramic one.