级联式变截面压电换能器尺寸对其性能的影响

Influence of size of cascaded variable section piezoelectric transducer on performance

研究了一种新型的级联式变截面压电换能器,它由两段金属圆柱、一段金属圆锥和两组轴向极化的压电陶瓷晶堆组成,并以机械端串联、电端并联的形式相连接,且换能器的两端半径远小于纵向振动尺寸。基于一维理论,得到了换能器的机电等效电路以及共振频率方程和反共振频率方程,进而研究了换能器在基频和二次谐频振动下的共振频率、反共振频率及有效机电耦合系数与压电陶瓷晶堆间距离和金属圆锥尺寸之间的关系。将理论计算所得共振频率、反共振频率与COMSOL模拟结果进行比较,二者所得结果一致,研究表明选择合理的换能器尺寸可以有效优化其性能。

A new type of the cascaded variable section piezoelectric transducer was presented.The transducer was composed of two-section metal cylinder, one metal cone and two sets of axially polarized piezoelectric ceramic crystal stacks, which were connected in series mechanically and parallel electrically.The radius of the two ends of the transducer was much smaller than the longitudinal vibration size. Based on the one-dimensional theory, the electromechanical equivalent circuit of the transducer was derived and the resonance/anti-resonance frequency equations were obtained. The fundamental mode and the second mode of the transducer were analyzed. The dependency of the resonance/anti-resonance frequency and the effective electromechanical coupling coefficient on the distance between two piezoelectric stacks were studied. The dependency of the resonance/anti-resonance frequency and the effective electromechanical coupling coefficient on the dimensions of metal cone were obtained.The calculated results of resonance/anti-resonance frequency were compared with COMSOL simulation results. The results showed that the simulation results agreed with the calculated results.