Vibration mitigation and energy harvesting of vibro–impact dielectric elastomer oscillators

Dielectric elastomers (DEs), as a type of intelligent materials, have the characteristics of light weight, high energy density, high conversion efficiency, and damping effect, and thus can achieve the potential dual-use value of concurrent vibration mitigation (VM) and energy harvesting (EH) by combining with mechanical structures. This paper investigates the vibro-impact dielectric elastomer oscillator (VI DEO) and the proposed rolling VI DEO (RVI DEO) to achieve or enhance the potential dual-use value of DE oscillators. First, the schematics of the VI DEO and the RVI DEO are elaborated in detail. Then, the two dynamics analysis models of the linear oscillator (LO)-VI DEO and LO-RVI DEO systems are developed. On this basis, the VM and EH performances of the two DE oscillators under transient and harmonic excitations are numerically studied. It is demonstrated that the two DE oscillators have the most effective VM performance when the LO-VI DEO and LO-RVI DEO systems behave most efficiently in the 1:1 resonance vibro-impact regime with targeted energy transfer (TET). Hence, to achieve this response regime, the influences of the parameters such as the ball's mass, impact distance, pre-stretched ratio and friction coefficient of the two DE oscillators on their VM and EH performances are investigated one by one. The research results show that the most effective VM can only be achieved by adjusting the ball's mass, and the largest output power is generated in the resonance region. Hence, we further perform multi-parameter optimization to find the two DE oscillators with the best performance. Based on the multi-parameter optimization results, the performances of the two optimal oscillators are evaluated under mid-energy level harmonic and variable-frequency excitations with different amplitudes, and it is proved that both optimal DE oscillators not only have good performances, but also the RVI DEO has a better robustness.