title: Multiscale instabilities in soft heterogeneous dielectric elastomers.
abstract: The development of instabilities in soft heterogeneous dielectric elastomers is investigated. Motivated by experiments and possible applications, we use in our analysis the physically relevant referential electric field instead of electric displacement. In terms of this variable, a closed form solution is derived for the class of layered neo-Hookean dielectrics. A criterion for the onset of electromechanical multiscale instabilities for the layered composites withanisotropicphases is formulated. Ageneralcondition for the onset of the macroscopic instability in soft multiphase dielectrics is introduced. In the example of the layered dielectrics, the essential influence of the microstructure on the onset of instabilities is revealed. We found that: (i)macroscopicinstabilities dominate at moderate volume fractions of the stiffer phase, (ii)interfaceinstabilities appear at small volume fractions of the stiffer phase and (iii) instabilities of afinitescale, comparable to the microstructure size, occur at large volume fractions of the stiffer phase. The latest new type of instabilities does not appear in the purely mechanical case and dominates in the region of large volume fractions of the stiff phase.
authors: Department of Mechanical Engineering , Massachusetts Institute of Technology , Cambridge, MA, USA.
authors: S
authors: S
authors: Rudykh
authors: Division of Engineering and Applied Science , California Institute of Technology , Pasadena, CA, USA.
authors: K
authors: K
authors: Bhattacharya
authors: Department of Mechanical Engineering , Ben-Gurion University , Beer-Sheva 84105, Israel.
authors: G
authors: G
authors: Debotton
keywords: composites; dielectric elastomer; electroactive; electroactive polymer; instability; microstructure