狭缝式环形超声聚能器的径向振动特性

对一种狭缝式环形超声聚能器的径向振动特性进行了研究。基于机电类比原理,通过引入面积比系数,推出了聚能器的径向振动机电等效电路及频率方程;得出了其径向位移振幅放大系数表达式。通过数值计算,探讨了聚能器第1、2阶径向共振频率及振幅放大系数与其半径比的关系;分析了狭缝长度、角度及数目对聚能器振幅放大系数及共振频率的影响,并进行了有限元仿真。研究表明,聚能器的振幅放大系数随其半径比的变化存在极大值,并随狭缝数量、长度及宽度增加而增大;而其径向共振频率则随三者的增加而减小,理论与有限元仿真及实验结果符合较好。 

Radial vibration of an annular ultrasonic concentrator with multiple radial slits

The radial vibration characteristics of an annular ultrasonic concentrator is presented and studied.Based on the electro-mechanical analogy and by introducing the area ratio coefficient,the radial equivalent circuit and the frequency equation of the concentrator are derived.And the radial displacement amplitude magnification coefficient of the concentrator is obtained.By numerical calculating,the relationship between the radial displacement amplitude magnification coefficient,the resonance frequency at the first and second order vibration modal and the radius ratio of the concentrator are investigated.Also,the relationship between the radial displacement amplitude magnification coefficient and resonance frequency of the concentrator and the length,the angle and the number of the silts is analyzed.It is illustrated that a maximum of displacement amplitude magnification coefficient of the concentrator appears with the increase of the radius ratio,and the amplitude magnification coefficient increases as the slit length,the angle and the number of the silts increases,while the radial resonance frequency of the concentrator decrease as the length,the angle and the number of the silts increased.The theoretical resonance frequencies are in good agreement with that of the FEM simulations and measurement.