Finite element modeling and parametric analysis of a dielectric elastomer thin-walled cylindrical actuator

Due to their high energy density, dielectric elastomers have been widely studied over the last decades, in particular, for applications requiring electromechanical actuators. They are commonly designed using thin-walled elastomeric structures, with particularly interesting dielectric properties, that are covered by flexible electrodes in their upper and lower surfaces. Unlike other potential electromechanical materials, such as piezoelectric ceramics, dielectric elastomers may undergo high deformation levels and, thus, present themselves as interesting alternatives for applications that require greater deformations and/or displacements. Nevertheless, in order to profit from this advantage, the design of dielectric elastomer actuators requires predictive models that properly account for both structural and material behavior under high deformations and also electromechanical coupling. The main objective of this work is to present an assessment of existing nonlinear elastic theories well suited to dielectric elastomers that allow to propose a finite element procedure capable of predicting the electromechanical behavior of a plate-type structure. Finite element results are compared to analytical and experimental ones. Then, the procedure is applied to carry out a parametric analysis of a dielectric elastomer cylindrical actuator. The obtained results indicate that the proposed finite element procedure is capable of well representing the actuator operation. It is shown that important deformations and displacements may be obtained with the proposed dielectric elastomer cylindrical actuator, even when subjected to opposing forces, and its performance may be tuned by changing its geometrical properties.