Using Circuit-Induced Viscoelastic Damping to Enhance Quasi-Zero-Stiffness Vibration Isolator

Quasi-zero-stiffness (QZS) vibration isolators have been widely studied previously for low-frequency vibration isolation, which usually possesses viscous damping. However, viscous damping has an intrinsic weakness: the resonance response suppression via damping design must be accompanied by the sacrifice of high-frequency performance. To surmount this trade-off, this paper proposes circuit-induced viscoelastic damping (CIVED) to enhance the QZS isolator. The derived governing equation of motion indicates that the CIVED-QZS isolator is a third-order dynamical system. The primary response is calculated analytically and the numerical simulations are conducted to reveal more complex nonlinear dynamic behaviors. The vibration isolation performance is analyzed in comparison to the conventional QZS isolator, and some essential characteristics of the CIVED-QZS isolator are discussed. The results indicate that the electromechanical coupling coefficient can be optimized to attain the lowest peak transmissibility without affecting the high-frequency transmissibility. It was also found that the external inductor is the key factor for generating viscoelastic damping.