介电型电活性聚合物圆柱驱动器特性

介电型电活性聚合物(Electroactive polymer, EAP)驱动器的动、静态特性是其合理使用及优化设计的重要依据。构建圆柱形驱动器几何模型描述其几何变形，结合EAP膜机电耦合方程推导驱动器轴向线性运动的动力学方程。驱动器的电压-位移数值计算结果显示内外层EAP膜柔性电极涂覆方式会影响驱动器位移。基于驱动器的电压位移关系，对其主要失效形式进行讨论。将基于neo-Hookean弹簧的1个时间常数黏弹性模型修正为具有2个时间常数的模型，并将2种模型运用于阶跃和周期电压激励下的驱动器动态响应研究。理论计算与试验结果的对比分析表明，2个时间常数的黏弹性模型对驱动器的动态位移描述更为准确。在周期激励电压下，提高频率会显著减小驱动器位移幅值，驱动器的“激励死区”会减小其振动中心偏移及振动幅度。

Characteristics of Dielectric Electroactive Polymer Cylindrical Actuator under Voltage Activation

The dynamic and static characteristics of a dielectric electroactive polymer (EAP) actuator is the foundation for its reasonable operation and optimizing design. The geometrical deformation of the cylindrical actuator can be depicted through constructing a geometry model; furthermore, the dynamic formulation for the axial linear movement is also deduced based on the electromechanical coupling equations of EAP. The relation curve between the displacement and voltage of the cylindrical actuator, obtained through numerical calculation, reveals that the coating method for the outer and inner layer of the flexible electrodes can influence the actuator displacement. Based on the relationship between voltage and displacement, the main failure forms of the actuator are also discussed. Modifying the one-time-constant viscoelastic model, based on the neo-Hookean springs, to two-time-constant model, the two models are applied to study the dynamic responses of the actuator excited by step and periodic voltage. Comparative analysis of theoretical calculation and experiment results shows that the two-time-parameter viscoelastic model can describe the dynamic displacement more accurately. The displacement amplitude of actuator, under periodic voltage excitation, will be significantly reduced through increasing frequency, while the vibration center offset and vibration amplitude reduced due to “excitation dead zone”.