Modeling of dielectric viscoelastomers with application to electromechanical instabilities
Document Type
Article
Publication Date
10-1-2016
Abstract
Soft dielectrics are electrically-insulating elastomeric materials, which are capable of large deformation and electrical polarization, and are used as smart transducers for converting between mechanical and electrical energy. While much theoretical and computational modeling effort has gone into describing the ideal, time-independent behavior of these materials, viscoelasticity is a crucial component of the observed mechanical response and hence has a significant effect on electromechanical actuation. In this paper, we report on a constitutive theory and numerical modeling capability for dielectric viscoelastomers, able to describe electromechanical coupling, large-deformations, large-stretch chain-locking, and a time-dependent mechanical response. Our approach is calibrated to the widely-used soft dielectric VHB 4910, and the finite-element implementation of the model is used to study the role of viscoelasticity in instabilities in soft dielectrics, namely (1) the pull-in instability, (2) electrocreasing, (3) electrocavitation, and (4) wrinkling of a pretensioned three-dimensional diaphragm actuator. Our results show that viscoelastic effects delay the onset of instability under monotonic electrical loading and can even suppress instabilities under cyclic loading. Furthermore, quantitative agreement is obtained between experimentally measured and numerically simulated instability thresholds. Our finite-element implementation will be useful as a modeling platform for further study of electromechanical instabilities and for harnessing them in design and is provided as online supplemental material to aid other researchers in the field.
Identifier
84974679330 (Scopus)
Publication Title
Journal of the Mechanics and Physics of Solids
External Full Text Location
https://doi.org/10.1016/j.jmps.2016.05.033
ISSN
00225096
First Page
213
Last Page
229
Volume
95
Grant
1463121
Fund Ref
National Science Foundation
Recommended Citation
Wang, Shuolun; Decker, Martina; Henann, David L.; and Chester, Shawn A., "Modeling of dielectric viscoelastomers with application to electromechanical instabilities" (2016). Faculty Publications. 10242.
https://digitalcommons.njit.edu/fac_pubs/10242