EAP-Actuators with Improved Actuation Capabilities for Construction Elements with Controllable Stiffness

Abstract:

This contribution considers an actuator based on Electroactive Polymers (EAPs) which is used for constructional elements with controllable stiffness. The actuator consists of a Danfoss PolyPower EAP-foil and a supporting structure which applies the necessary pre-straining force to the foil. Usually, such structures have a constant spring stiffness which strongly limits the actuation range. The novel actuator shows a highly nonlinear spring stiffness for pre-straining the foil. Therefore, the pre-straining force is nearly constant all over the entire actuation range. This behavior can be used to double the possible actuation range. Such structures are suitable to be used in construction elements with variable stiffness. The contribution shows the basic function of this actuator and its capabilities for the application in new smart, self-sensing and self-controlling composite materials for lightweight constructions. The theoretical background of highly nonlinear spring stiffness is discussed and transferred to the developed structures. The theoretical calculations are based on analytic calculations and finite element analyses and are verified by experimental set-ups consisting of different actuators both with constant and highly nonlinear pre-straining spring constant.

• Periodical: Advances in Science and Technology (Volume 79)
• Pages: 75-80
• DOI: https://doi.org/10.4028/www.scientific.net/AST.79.75
• Online since: September 2012
• Authors: Markus Henke, Jörg Sorber, Gerald Gerlach
• Keywords: Electroactive Polymer, PolyPower, Post-Buckling Actuation, Smart Structures, Variable Stiffness

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