基于COMSOL MULTIPHYSICS的多层介质悬臂结构特性研究

The Multi-Media Cantilever Structure Characteristics Research Based on COMSOL MULTIPHYSICS

摘要: 本文对多层介质悬臂梁结构特性进行了研究。根据Castigliano位移理论，对等效单层介质模型的结构刚度进行了修正，推导出适合于多层介质的等效结构刚度通式，更准确地表征出多介质悬臂梁结构的力电特性。同时，利用COMSOL Multiphysics软件对多介质层悬臂梁结构进行模拟分析，结果表明，当介质层数从2层增加10层时，等效结构刚度增加了1.9671 N/m，系统基本频率提高了22 Hz。在偏置电压为8 V的条件下，随着悬臂梁内部层数从2层增加到10层时，位移量从613 nm减小到544.2 nm。分析得出，同一悬臂梁随着内部介质层数的增加，由于各层材料的杨氏模量和热膨胀系数不同，层与层之间的形变产生了相互抑制作用，同时各介质层之间存在的静摩擦力产生了粘滞效应，等效结构刚度逐渐增大；固有频率及动态性能随着介质层数的增加而提高。

Abstract: Characteristics of multi-media cantilever structure is studied in this letter. According to Castigliano displacement theory, stiffness formula of single-medium model is revived, an general formula which can accurately represent the electrical characteristics of multimedia structure is deduced. Cantilever structure is simulated with the use of COMSOL Multiphysics. It turns out that the equivalent stiff-ness increases by 1.9671 N/m and the fundamental frequency increased 22 Hz when the layer raise form 2 to 10. In the same load, the deformation decreased from 613 nm to 544.2 nm. With the increasing of layers, deformation between the layers generates inhibition because of different Young’s modulus and thermal expansion coefficient. Meanwhile, static friction of layers brings out viscous effect and enhances the equivalent stiffness. Natural frequency and dynamic property of the system improved with the increasing of medium layers.