Theoretical Investigations On The Stability And Viscoelasticity Of Dielectric Elastomer Actuators

ectric elastomer is a type of elastomer materials with high dielectric constant, and can he shape or size under the electrical stimulation. It can be restored to the original shape or n the electrical stimulation is released, causing the electrical energy to transform into al energy. It has many excellent features, such as light weight, high energy density, fast large deformation and not easy fatigue and damage. Dielectric elastomer is the most electroactive polymer materials to produce the intelligent active actuators. Possible ons include medical devices, robotic, adaptive optics and energy harvests. Sandwich a a dielectric elastomer between two compliant electrodes. When a voltage is applied the two electrodes, the layer reduces in thickness and expands in area which due to the tie forces, so that the same voltage will induce an even higher electric field. This positive may cause the elastomer to thin down drastically, when the electric field exceeds the lectric field, resulting in the actuator breakdown. In this paper, we study the dynamics and stability of the thick-walled dielectric elastomer spherical and cylindrical shell which static and periodic voltage, and analyze the viscoelastic behavior of the dielectric·balloon.ly, based on the hypothesis of the incompressible material, we use the neo-Hookean nd the Arruda-Boyce model to analyze the electromechanical instability of the led spherical shell which is under static voltage. The electric field in the shell is eneous and varies with the radius of the shell. The instability in the spherical shell with thickness and different pre-stresses is discussed. When the elastomer obeys the oyce model, the stability is related to the parameter n. The spherical shell will appear ugh instability and pull-in instability for different values of the parameter n.ondly, we study the dynamics response and stability of the cylindrical shell which is under d periodic voltage. We get the ordinary differential equation which describes the it of cylindrical shell using the neo-Hookean material model. The voltage curves as a of the deformation with different thickness and different pre-stresses are given. When a periodic voltage is applied, the movement of the shell is cyclical or intending to cyclical nonlinear vibration. We calculate nature frequency of the cylindrical shell, and get the periodic solutions using the shooting method, analyze the stability of the periodic solutions using the numerical method. The vibration amplitude curves as a function of the incentive frequency of periodic voltage are given.Finally, based on the viscoelastic model of the dielectric elastomer which established by Hong, we study the viscoelastic behavior of the dielectric elastomer balloon which subjected an electric field. We get the equation which describes the movement of the balloon, and we also get the response curves of the balloon which driven by standard static and dynamic electric fields by numerical simulation. At last, the hysteresis and energy loss problems of the viscoelastic balloon in different frequency of electric fields are discussed.