介电薄膜换能器的非平衡力电行为分析

发布时间：2018-04-08 17:10

本文选题：介电薄膜　切入点：力电换能器　出处：《兰州理工大学》2017年硕士论文

【摘要】：介电聚合物属软物质,当上下表面附着有柔顺电极的介电聚合物薄膜受外加电场作用时,该薄膜将减小厚度,同时扩大面积,产生大变形,将电能转化为机械能。加之此类材料具有轻质、高效、低成本、能量密度高、无噪音、易加工等优异的材料和力学性能,近年来,此类材料受到了学术界和工业界的广泛关注,可被设计成致动器、传感器及能量采集器等换能器,并已在或有望在人工肌肉、机器人、光学、生物医学、电子产品、能量采集等领域发挥重要的作用,具有潜在的巨大的市场价值。目前,学者们对介电聚合物薄膜换能器的作动机理、失效模式及其力电弹性行为已做了大量卓有成效的理论及实验研究,而对其粘弹性力电行为的刻画不多,本文则围绕介电聚合物薄膜换能器的粘弹性力电行为展开研究,所开展的创新性的研究工作如下:(1)建立了中心粘接有轻质圆盘的圆形介电薄膜致动器,受内压及电压作用、产生面外大变形的粘弹性力学模型,并对其力电粘弹性行为进行了研究。通过非平衡热力学理论,推导得到了该致动器的状态方程及控制方程;采用弹簧-黏壶流变模型,得到了该致动器的运动学方程。数值得到了所考虑变量和变形薄膜轮廓的演变过程并进行了图示说明。计算中,考虑了内压、电压及设计参数等对介电薄膜粘弹性行为的影响效应,结果表明:内压、电压及设计参数对该致动器的力电粘弹性行为都有着显著影响。(2)建立了上下两端连接有轻质刚性圆盘,受内压和电压作用,产生轴对称大变形的管状介电薄膜致动器的粘弹性力学模型。经推导得到了描述其大变形的控制方程及描述其粘弹性的运动学方程,并联合使用打靶法及改进的欧拉法对方程进行了数值求解,得到了各物理量的变化规律。计算中,重点考虑了内压、电压及管状介电薄膜的纵横比对该致动器力电粘弹性行为的影响效应,结果表明,它们极大地影响着其力电粘弹性行为。(3)建立了受轴向拉力和电压作用,上下两端连接有轻质刚性圆盘的管状介电薄膜致动器的粘弹性力学模型。通过准静态平衡法,推导得到了描述该致动器大变形的控制方程,而运动学方程仍由流变模型所给出。经数值求解,得到了各物理量的分布规律。计算中,重点研究了力电载荷、薄膜的环向预拉伸、薄膜的纵横比对该致动器粘弹性力电行为的影响。结果表明,它们的影响显著。(4)建立了管状薄膜-弹簧致动器的力学模型。通过准静态平衡法,推导出描述该致动器大变形的控制方程,运动学方程仍由流变模型所给出。通过数值计算,分别研究了该模型在恒定力电载荷和周期力电载荷作用下的粘弹性行为。从计算结果得出,弹簧的刚度、加载率对薄膜的时间依赖行为影响显著。本文的研究将有助于更好地掌握此类介电薄膜致动器的粘弹性力电行为,并为这几款类致动器的优化设计提供理论指导,大力推进这几款致动器的工程化应用。
[Abstract]:Dielectric polymer is a soft material, when the upper and lower dielectric polymer film attached to the surface of the electrode by compliant external electric field, the film thickness will decrease, while expanding the area, large deformation, electrical energy into mechanical energy. And this kind of material has the advantages of light weight, high efficiency, low cost, high energy density, no noise, easy processing and excellent material mechanical properties, in recent years, this kind of material has attracted wide attention in both academia and industry, can be designed as actuator, sensor and transducer energy collector, and has been or is expected in the artificial muscle, robotics, optics, biomedicine, electronic products, play an important role in energy acquisition and other fields, has great potential market value. At present, the actuating mechanism of the scholars on the dielectric polymer thin film transducer, failure mode and stress elastic behavior has made a lot of theoretical and very fruitful Experimental study and characterization of the viscoelastic mechanical and electrical behavior is not much studied viscoelastic mechanical and electrical behavior of the dielectric polymer thin film transducer, the innovation of the research work are as follows: (1) the establishment of a circular dielectric thin film actuator bonded with light disk center, under internal pressure and the effect of voltage, viscoelastic mechanics model of plane deformation, and the mechanical and electrical viscoelastic behavior were studied. The non-equilibrium thermodynamic theory, derive the state equations and control equations of the actuator; the spring dashpot rheological equations of kinematics are obtained by using the model of the actuator is obtained. Numerical by considering the variables and deformation of the thin film profile evolution process were illustrated. In the calculation, considering the internal pressure, effect, influence of the voltage and the design parameters of dielectric film viscoelastic behavior results show that the internal pressure, and voltage The design parameters have significant influence on the viscoelastic behavior of electric actuator force. (2) the establishment of the upper and lower ends are connected with light rigid disk, inner pressure and voltage, viscoelastic mechanical model of axisymmetric large deformation of the tubular dielectric thin film actuator. The deduced to describe the large deformation the control equation and the kinematics equation to describe the viscoelastic properties, and the combined use of shooting method and the improved Euler method for solving equations, obtains the variation law of each physical quantity. In the calculation, considering the internal pressure, the effect of the electric actuator, and force viscoelastic behavior than voltage and tubular dielectric film the results show that it greatly affects the mechanical and electrical viscoelastic behavior. (3) established by the axial force and voltage, the upper and lower ends connected with viscoelastic lightweight rigid disk tubular dielectric thin film actuator Model. Through the quasi-static equilibrium method is derived to describe the control equation of the large deformation of the actuator, and the kinematics equation by rheological model presented. By numerical calculation, the distribution of various physical quantities. In the calculation of mechanical and electric loads, film circumferential pre stretch, the influence of vertical and horizontal actuator the viscoelastic behavior of the electric force alignment film. The results show that their impact is significant. (4) established the mechanical model of tubular film spring actuator. Through the static equilibrium method, the governing equations describing the large deformation of the actuator are derived. The motion equation is given by the rheological model. By numerical calculation. The viscoelastic behavior of the model under constant force electric load and periodic force electrical loads are studied. The computational results show that the stiffness of the springs, the loading rate of the films significantly affects the time dependent behavior. This study will be It helps to better understand the viscoelastic force and electric behavior of such dielectric film actuator, and provide theoretical guidance for the optimization design of these kinds of actuators, and vigorously promote the engineering applications of these actuators.

【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O34;TB383.2

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