| Popis: |
Dielectric elastomer membrane(s) are smart material(s) that produce large actuation strains. They are also a class of electroactive polymers that function as actuators and sensors to convert and sense electrical signals to mechanical deformation and vice versa. Unique properties, such as flexibility, lightweight, and the ability to have an electrical field-induced deformation, make the dielectric elastomer membrane an ideal solution to the challenges faced by many applications, including the wings of unmanned aerial vehicles. This study aims to analyze the modal characteristics and aerodynamics of the dielectric elastomer membrane both computationally and experimentally. An electroactive membrane, VHB 4910, is considered the specimen, and the conductive material of carbon grease is used as an insulator on both surfaces of the membrane. Finite element models are developed to compute the resonance frequencies and mode shapes. The computational results of the modal analysis are validated using a closed-loop vibration testing experimental arrangement and digital image correlation system. Aerodynamic analyses are conducted using a wind-tunnel setup with a data acquisition system. A shape sensitivity study is also performed to see how five different shapes of a constant area affect the aerodynamics and vibrations of the membrane. The modal characteristics are controlled by adjusting the prestretch, true stress, and applied voltages. The natural frequencies decrease as the applied voltage increases. The aerodynamic coefficients increase with the angle of attack up to a particular range. |
