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TitleFinite element modelling of dielectric elastomer minimum energy structures
Publication TypeJournal Article
Year of Publication2009
AuthorsO'Brien, B., McKay T., Calius E.P., Xie S., and Anderson I.
JournalApplied Physics A: Materials Science and Processing
Pagination507 - 514
Date Published2009
ISSN09478396 (ISSN)
KeywordsActuators, Bending (deformation), Bending (forming), Bending actuators, Blocked forces, Case studies, Computational times, Dielectric constants, Dielectric elastomers, Experimental datums, Finite element method, Finite element modelling, Finite element models, Flexible frames, Frame stiffnesses, Free displacements, Magnitude reductions, MATHEMATICAL MODELS, Minimum energy structures, Model structures, New models, Plastics, Polymers, Rubber, Simulation methods, Strain energy functions, Systems engineering
AbstractThis paper presents an experimentally validated finite element model suitable for simulating the quasi-static behaviour of Dielectric Elastomer Minimum Energy Structure(s) (DEMES). A DEMES consists of a pre-stretched Dielectric Elastomer Actuator (DEA) adhered to a thin, flexible frame. The tension in the stretched membrane causes the frame to curl up, and when a voltage is applied, the frame returns to its initial planar state thus forming a useful bending actuator. The simulation method presented here incorporates a novel strain energy function suitable for simulating general DEA actuator elements. When compared against blocked force data from our previous work, the new model provides a good fit with an order of magnitude reduction in computational time. Furthermore, the model accurately matched experimental data on the free displacement of DEMES formed with non-equibiaxially pre-stretched VHB4905 membranes driven by 2500 V. Non-equibiaxially pre-stretching the membranes allowed control of effective frame stiffness and bending moment, this was exploited by using the model to optimise stroke at 2500 V in a hypothetical case study. Dielectric constant measurements for non-equibiaxially stretched VHB4905 are also presented. © 2008 Springer-Verlag.

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