模型参数对IPMC变形性能影响分析

Analysis of modeling parameters affecting on IPMC deformation property

基于电场-化学场-机械场耦合作用机理,采用数值模拟方法,建立了RC模拟电路,分析了IPMC在外加电压场作用下模拟参数对电流和电流积分的影响;采用标准三参数模型模拟Nafion膜线黏弹性力学行为,得到了随时间衰减的杨氏模量表达式。分析结果表明:膜内电流积分是一个决定性因素,它直接控制着膜内钠离子的迁移运动;电容增大时,膜内电流积分增大,从而加速了膜内钠离子的迁移运动,同时宏观位移也随之增大;电阻增大时,膜内电流积分与宏观位移均随之减小。引入静电应力作为初始应力,对悬臂梁挠曲变形进行了细观分析,结果表明其最大挠曲变形的旋转角可达到24°。

Based on electro-chemical-mechanical field interaction,the aim of the paper is to study the IPMC（ion-exchange polymer metal composite） macroscopic deformation and parameters effect by numerical simulation method.The virtual RC（resistor-capacitor） circuit is constructed to reflect the influence of simulation parameters on the electric current and current integration under the action of external electric field.The calculation results illustrate that the current integration is a decisive parameter.It can be used to control the migration movement of the N ＋ ion within the Nafion membrane.If increasing the capacitor,the current integration enlarge and moving speed of N ＋ ion within the Nafion membrane speed up,so that the macroscopic deformation increases.Nevertheless,if increasing the resistance,the current integration decline and the macroscopic deformation decrease.Using the standard three-parameter visco-elastic model,the numerical simulation is carried out to describe the visco-elastic mechanical behavior of Nafion membrane.The expression about the Young’s modulus with time decay is obtained,which can be used to describe the bending deflection of cantilever beam more accurately.Through the micro-analysis,the deformation about IPMC can be achieved by introducing the static-electric stress as the initial stress.The rotate angle corresponds to the maximum deflection of the cantilever beam is 24 degree.