High-Frequency Dynamic Model of a Pre-Loaded Circular Dielectric Electro-Active Polymer Actuator

In this work a high-frequency dynamic model of a pre-loaded circular DEAP actuator is developed and experimentally validated. The model is capable of predicting both the static and dynamic response of the actuator. The static response is modeled based on a free energy approach and consists of an Ogden term representing the elastic energy, and a electrical term representing the electrical-mechanical coupling [1]. The addition of viscoelastic elements (spring-dashpot configurations) enables the model to capture the dynamic response. The Ogden coefficients were first identified through a quasi-static force-displacement test of the actuator. A series of validation tests of the actuator at various pre-loads and voltage frequencies showed the model to be in good agreement with the experiments. The model is shown to accurately predict the actuators observed natural frequencies as the pre-deflection and the stiffness of the spring were changed. Future work will include additions to the model to account for relaxation and creep inherent in DEAP material.