Research On The Comprehensive Performance And Typical Application Of Dielectric Elastomer Based On Multiphysics Coupling

As a new category of electro-active polymer,dielectric elastomer(DE)possesses advantages that many traditional hard materials in engineering do not have,like rapid response,large deformation,high energy density,light weight,and low price.When a DE membrane is sandwiched between two compliant electrodes,the polymer film will generate an deformation of several times its own planar area driven by voltage applied,and will recover its original shape when voltage is removed.Since the DE film coated with two electrodes corresponds to a flexible plane-parallel capacitor,DE devices can convert mechanical energy into electrical one under certain conversion cycles.Owing to these traits,dielectric elastomer shows great potential in actuator,artificial muscle,bio-mimic robot,energy harvester,and so on.Although studies on DEs have emerged in an endless stream,there is a lack of research on DE multiphysics coupling and their applications on the basis of such model.In this thesis,a multiphysics coupling model of DE(force+electric+temperature)is established with consideration of viscoelasticity current leakage as well as failure modes(rupture,loss of tension,electric breakdown and electromechanical instability).For actuation application,a dynamic multiphysics coupling model on the basis of inertial effects and Euler-Lagrangian kinetics equation is established and the dynamic and quasi-static responses of DE under various typical loading forms are compared.It can be concluded from simulation that when the membrane of DE is driven by a linear or harmonic voltage with high amplitude and frequency,the quasi-static and dynamic responses will be different.For energy harvesting,the behaviors of a DE generator are investigated in detail under a Carnot-like harvesting cycle.Based on comprehensive multiphysics coupling model,it is concluded that the DE generator can possess better conversion efficiency at lower temperature(273~333 K).For vibration control,based on the mechanism of spring roll actuator,the DE film is combined into a spring-mass system to study the vibration behaviors of the combined system.Relevant factors are fully studied and the programmable vibration control using DE is realized.