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人工肌肉是指具有类似肌肉特性的材料,这些材料在外界激励下,可以实现大变形,且响应速度快。本文总结两类人工肌肉本构模型的研究成果:一类是介电高弹体,另一类是响应性凝胶。本文中提到的本构模型仅限于用自由能函数导出的情形。对于介电高弹体材料,分别综述超弹性模型和粘性超弹性模型。在超弹性模型中,列出目前研究中使用较多的一些本构模型的自由能函数具体表达式;比较neoHookean、Gent、Arruda-Boyce和Ogden四种模型在单轴拉伸和等双轴拉伸两种情形下的名义应力-伸长曲线;给出了考虑一些重要因素的研究模型,这些因素包括材料可压缩性、取向极化、变介电常数、热耦合、受纤维约束、流体耦合以及空气耦合等。对于响应性凝胶,分别综述水凝胶、pH敏感性凝胶、温度敏感性凝胶、聚电解质凝胶以及反应性凝胶等的本构模型。这些精确、可靠和有效的本构模型,将有助于开展人工肌肉系统的性能分析和预测,甚至揭示其内在特性和本质规律。
Artificial muscle refers to the material with similar muscle properties, these materials in the external excitation, can achieve large deformation, and fast response. This article summarizes the research results of two types of artificial muscle constitutive models: one is a dielectric elastomer and the other is a responsive gel. The constitutive model mentioned in this article is limited to the case derived from the free energy function. For dielectric elastomer materials, the superelastic models and viscous hyperelastic models are reviewed respectively. In the hyperelastic model, the specific expressions of the free energy function of some constitutive models used in the present study are listed. Four models of neoHookean, Gent, Arruda-Boyce and Ogden are compared in uniaxial stretching and biaxial stretching The nominal stress-elongation curves in both cases are extended. A study model considering some important factors is given, including material compressibility, orientation polarization, variable dielectric constant, thermal coupling, fiber confinement, fluid coupling As well as air coupling. For responsive gels, the constitutive models for hydrogels, pH-sensitive gels, temperature-sensitive gels, polyelectrolyte gels and reactive gels, respectively, are reviewed. These accurate, reliable and effective constitutive models will help to carry out the performance analysis and prediction of the artificial muscular system, and even reveal its inherent characteristics and essential laws.