An experimental study on the dynamic response of dielectric elastomer membranes

摘要

Dielectric Elastomer Actuators (DEAs) have received considerable attention recently due to their large strains, over 100% in some cases, when subject to an electric field. Previous research yielded a large deformation quasi-static model that describes the out of plane deflections of clamped diaphragms. The numerical modeling results compare well with experimental results for the same configuration. A theoretical dynamic model has also been developed for the dynamic inflation of a spherical DEA membrane. With relevance to dynamic applications, the time varying response of dielectric elastomer membranes configured for out-of-plane deflections has not been reported until now. In this paper, an experimental investigation and analysis of the dynamic response of a dielectric elastomer membrane is reported. The experiments were conducted with DEAs fabricated from VHB 4905 films and carbon grease electrodes. The experiments covered the electromechanical spectrum by investigating membrane behavior due to (ⅰ) a voltage time-varying input and (ⅱ) a mechanical time varying input, resulting in a combined electromechanical loading state during the experiments. The results reveal that the response of the membrane is a departure from the classical dynamic response of continuum membrane structures. As a result of this work, we have identified which typical modeling assumptions are valid and hence can authentically be used to develop new dynamic predictive modeling tools.