Electromechanical instability and snap-through instability of dielectric elastomers undergoing polarization saturation

By applying a voltage, electric charge will be induced on the surface of dielectric elastomers. Generally, the charge increases with the level of voltage. When the voltage reaches to a certain value, the charge would not increase any more due to the polarization saturation of dielectric materials. In this paper, a thermodynamic constitutive model, combined both the nonlinear dielectric and hyperelastic behavior as dielectric elastomers undergoing polarization saturation, has been developed. Analytical solutions have been obtained for situations incorporating strain-stiffening effect, electromechanical instability and snap-through instability. The numerical results reveal the marked influence of the extension and polarization saturation limits of elastomer material on its electromechanical instability and the snap-through instability. The developed constitutive model would be helpful in future research of dielectric elastomer based high-performance transducers.

Published by:  Mechanics of Materials 55 (2012) 60–72 http://www.sciencedirect.com/science/article/pii/S0167663612001421