由于电活性聚合物材料在电场作用下所表现出的许多独特的力电性能,如大应变、响应快、高能量转换率等特点,使得这种高分子智能材料引起了广泛关注,已被加工成作动器、传感器及俘能器等能量转换器,有望在工程领域发挥巨大作用.论文针对美国人工肌肉公司(ArtificialMuscleInc.)开发的一款电活性聚合物介电薄膜作动器的优化设计开展研究,主要研究了在外加力电载荷作用下,当薄膜发生面外轴对称大变形时,不同初始预拉伸即设计参数对薄膜厚度、拉伸变形、应力及薄膜中电场强度等的影响效应.该薄膜作动器有三个设计参数,结果表明,通过优化设计参数,在设计参数的某一组合下,薄膜的厚度、薄膜中的电场分布将趋于均匀,而薄膜的拉伸变形、应力并未呈现类似的均匀性.本文所提供的研究方法,可为此类作动器的优化设计提供基本的分析模式.
Due to their unique mechanical-electro properties in response to an applied electric field, in- eluding large strain, fast response, high energy-converting efficiency etc., the eleetroactive polymers (EAPs) have attracted extensive attentions. The EAPs have been designed into various transducers, e.g. actuators, sensors as well as energy harvesters. In this paper, we investigated the optimization design of a specific actuator presented by the Artificial Muscle Inc. , which is made of a layer of membrane of dielectric elastomer. This membrane actuator has three design parameters. Our emphasis was put on examining the effects of the initial pre-stretches on the membrane thickness, the stretches, the stresses as well as the e- lectric field in the membrane when the membrane undergoes out-of plane axisymmetric large deformation caused by the applied force and the voltage. The results show that the electric field in the membrane tends to be uniform under certain optimizing set of the design parameters while the stretches and the stresses in the membrane do not. The method proposed here can be used to optimize such actuators.