纯剪切模式介电弹性体发电机发电特性

为研究介电弹性体发电机的发电特性,基于COMSOL有限元软件建立了在纯剪切拉伸方式下的介电弹性体发电机有限元仿真机电耦合模型。该模型基于Yeoh超弹性材料本构,同时耦合发电机膜内静电力,根据可变电容理论对发电机电容变化及发电效果进行研究。设计了可Y向预拉伸的纯剪切拉伸装置,并在不同预拉伸条件下对发电机薄膜样本进行了拉伸实验,分析了其电容变化及发电效果。对比了仿真数据与实验结果,仿真模型的电容变化与实验测得的电容变化情况基本吻合,仿真模型一个周期内的输出电压变化与实验测得的电压变化基本吻合。实验及仿真结果表明,在相同的拉伸条件下,Y向预拉伸增大了初始电容及电容变化速率,且当Y向预拉伸λ=1时的上升电压为83V,而λ=2时的上升电压达到252V,改善了发电性能。本文提出的介电弹性体发电机新的研究方法为发电机样机设计提供了新的思路。

Power generation characteristics of dielectric elastomer generator under pure shear mode

In order to study the power generation characteristics of a Dielectric Elastomer Generator (DEG), a Finite Element (FE) model of the DEG under pure shear mode was established in the COMSOL Multiphysics commercial package. The model was based on the Yeoh constitutive relation of hyperelastic materials, coupled with the electrostatic force inside the generator membrane. The capacitance variation of the generator and the effect of power generation were studied. A pure shear tension apparatus was designed such that the DEG can be pre-stretched in the Y direction. Experiments to study the DEG performance under different pre-stretching conditions were carried out, and the capacitance change and power generating effect were obtained. The simulation data and the experimental results were compared and good agreement was found, therefore proving that the FE model is reliable. This study shows that, under the same tensile conditions, pre-stretching in the Y direction increases the initial capacitance and the capacitance changing rate of the DEG membrane. Hence, when the DEG was pre-stretched at λ=1, its rising voltage was 83 V, while at λ=2, its rising voltage was 252 V, thereby improving the power generation performance. The new research method of DEGs presented in this paper provides a new idea for the design of a generator prototype.