柔性电致伸缩聚合物薄膜结构的稳定性分析

Stability Analysis of the Flexible Electrostrictive Polymer Thin Film Structures

研究了外加电场作用下柔性电致伸缩聚合物薄膜的整体收缩、表面局部屈曲与整体失稳3种变形模式.在外加电场作用下,静电力(即Maxwell应力)成为薄膜变形的主要驱动力.通过力平衡和小扰度摄动法,获得电致伸缩聚合物薄膜发生表面局部屈曲和整体失稳变形模式的转换条件;通过数值算例对这2种变形模式与电场强度、薄膜尺寸、泊松比、介电常数和电致伸缩系数等之间的相关性进行讨论.分析结果显示,通过调节外加电场强度和材料参数,能够调控电致伸缩聚合物薄膜的变形模式.

The flat deformation,surface local wrinkling and global buckling of electrostrictive polymer thin films are studied subjected to the external electric field.Under the external electric field,the electrostatic stress（Maxwell stress）is the main driving force of the thin film deformation.Using the force balance and the linear perturbation methods,the transformation conditions of the surface local wrinkling and the global buckling of the electrostrictive polymer thin films are obtained.The relationship between these two deformation modes and various coefficients（the electric field strength,the film size,the Poisson′s ratio,the dielectric constant and the electrostrictive coefficients）are further discussed with numerical examples.The results show that we can control the deformation modes of the electrostrictive polymer thin films by adjusting the applied electric field and the material parameters.