Effect of geometrical parameters on the nonlinear behavior of DE-based minimum energy structures: Numerical modeling and experimental investigation

This work presents a finite element framework for simulating the quasi-static response of dielectric elastomer-based minimum energy structure (DEMES). The DEMES is an actuator formed by combining an inextensible frame and pre-stretched dielectric membrane that exhibits the unique shape-morphing characteristics of the actuator. A continuum strain energy-based model is implemented to investigate the impact of the different geometrical parameters on the performance of the DEMES actuator. Finite element analyses are performed using user-defined element (UEL) in ABAQUS for determining the equilibrium shape of the actuators and further investigating their electromechanical response. Experiments are performed using the commercially available VHB-4910 acrylic tape and the PET frames. 3D-printed reinforcements are used to impart anisotropy in the specimen. The findings of the model solutions provide preliminary insights on the alteration of the initial and final configurations of the DEMES affected by different geometrical parameters. It is observed that the shape of the electrode (rectangular, circular and triangular), compliant frame (rectangular, circular and triangular) and implemented stiffeners appreciably alter the attained initial configuration, final configuration and actuation range of the DEMES actuator. In general, this investigation can find its potential use in designing the futuristic DEMES through topological optimization of the compliant electrode and frame geometry together with material anisotropy of the elastomer.