Dynamic analysis of a dielectric elastomer - Based bistable system

Bistable structures, which are capable of oscillating between two stable states, have garnered significant attention and have been applied in many engineering domains due to their nonlinear behaviors. This paper presents for the first time a physical nonlinear bistable structure comprising a circular dielectric elastic membrane (DEM) coupled with four linear springs, enabling the DEM to achieve large deformations with the system oscillating between two stable equilibrium states. The nonlinear dynamics of the proposed bistable system under harmonic excitation is investigated through analytical, experimental, and numerical methods. First, the system structure is introduced and the corresponding dynamic model is established using Euler-Lagrange equations. Subsequently, the restoring forces of the DEM are experimentally measured, and the dynamic behavior of the bistable system is experimentally tested to validate the theoretical model. Furthermore, the dynamic responses of the system under different excitations are fully studied, and the influences of some key system parameters on the system response are analyzed. Research results demonstrate that the proposed structure exhibits bistable behavior under external excitation and the dynamic behavior of the system can be accurately predicted using the derived theoretical model. The proposed bistable structure contains rich dynamic behaviors including periodic motion, period-doubling bifurcations, and chaotic vibrations. The obtained parameters adjusting rules provide guidelines for the control of system's responses, which have potential applications in many fields such as vibration mitigation and energy harvesting.