基于负刚度预载荷机构的锥形介电型EAP驱动器研究

摘要

为了便于对介电型EAP驱动器进行优化设计,针对介电型EAP驱动器进行建模是极其重要的.结合弹性大变形理论及Maxwell应力建立介电型EAP材料的机电耦合模型,分析一种可以提高驱动器性能的负刚度预载荷机构,在此基础上建立基于负刚度预载荷机构的锥形介电型EAP驱动器模型.通过对微分代数方程组的求解,分析预载荷机构对驱动器驱动性能的影响,得出特定尺寸的锥形驱动器在不同驱动电压下的电压-位移曲线以及驱动器薄膜中的主延伸率、主应力分布情况,同时给出了锥形驱动器的力-位移曲线.最后将试验结果与理论分析进行比较,给出了导致偏差的原因.结果表明,本文建立的模型可以为锥形介电型EAP驱动器的设计应用提供参考依据.%Modeling a dielectric electroactive polymer (EAP) actuator is crucial for the design and optimization of actuators. By combining the large deformation elastic theory of membranes and Maxwell stress, this paper builds a model that describes the electromechanical coupling of dielectric EAP materials. A negative stiffness preload mechanism is analyzed which can significantly improve the actuation characteristics of an EAP actuator, and a model of a conically-shaped dielectric EAP actuator with negative stiffness preload mechanism is founded. By computing the nonlinear ordinary differential algebraic equations, the main factors that contribute to the performance of the conically-shaped dielectric EAP actuator are analyzed. The voltage-displacement curves and principal stretch ratio and the distribution of principal stress in the membrane under different voltages are obtained. At the same time, the force-displacement curve of the EAP actuator with voltage on or off is also derived. Finally, factors contributing to the deviation between theoretical analysis and experimental results are listed. The results show that the proposed model can guide the design and application of conically-shaped dielectric EAP actuators.