Loss of tension in electromechanical actuation of fiber-constrained viscoelastic dielectric elastomers

Abstract

Dielectric elastomers (DEs) under pure shear state can generate the giant deformation without the pull-in and snap-through instabilities. The pure shear state is usually achieved by using fibers to constrain the deformation in an in-plane direction. Since the DEs cannot support the compressed stress, the instability of loss of tension (LT) may occur in the fiber-constrained direction as the voltage-induced Maxwell stress increases. In this article, by incorporating the effects of different values of tensile force, applied voltage (including both step and ramp voltages), prescribed constrained deformation and viscoelasticity intensity, a viscoelastic model is employed to explore the instability of LT of fiber-constrained DEs with analysis of the electromechanical deformation and stress evolution.