多场耦合作用下光热敏感介电凝胶的力电耦合变形行为

介电弹性体在电场作用下将产生形变,为获得高的变形能,需对介电弹性体施以较强的电场,而强电场的施加可能诱发力电耦合失稳导致失效。针对光热敏感介电凝胶力电耦合变形行为,基于热力学和连续介质力学理论建立力电耦合变形模型,分析了光强、温度以及预拉伸对光热敏感介电凝胶力电耦合变形行为的影响,结果表明:无预拉伸时,随着电场强度的增大,光热敏感介电凝胶最终发生力电失稳,光强越小、温度越低发生力电失稳时的临界电压越高;预拉伸可显著改善力电稳定性,施加等双轴预拉伸后,凝胶厚度方向的伸长率显著变小,电场强度随电位移增大而线性增大,未出现力电失稳现象。

The Electric-mechanical Coupling Behavior of A Photo-thermal Sensitive Dielectric Gel under Coupling Multi-fileld Effect

The dielectric elastomer will deform under the action of electric field. Strong electric field should be applied to the dielectric elastomer to obtain high deformation energy, which may lead to electric-mechanical instability. In this paper, the electric-mechanical coupling behavior of photo-thermal sensitive dielectric gel was studied. Based on the theory of thermodynamics and continuum mechanics, the electric-mechanical coupling deformation theory of photo-thermal sensitive dielectric gel was established, the effects of temperature, light intensity and pretension on the electric-mechanical coupling deformation behavior of photo-thermal sensitive dielectric gel were studied. The results show that: In the absence of pretension, the electric-mechanical instability will occur finally with the increase of electric field intensity, and the smaller the light intensity and the lower the temperature is, the higher the critical electric intension is;Pretension can improve the electric-mechanical stability of photo-thermal sensitive dielectric gel. With equal biaxial pre-stretching, the extension rate in the direction of gel thickness decreases significantly, the nominal electric field strength increases linearly with the increase of nominal electric field.