Mechanical Properties and Performance of a Viscoelastic Low-Frequency Vibration Isolation and Mitigation Device

A viscoelastic (VE) low-frequency vibration isolation and mitigation device is proposed in this paper. The device consists of a VE damper, two oblique springs, and two oblique dampers to achieve low stiffness at the equilibrium position. Property tests on the VE damper, which is the core component of the device, are conducted, and a mathematical model is employed to describe the dynamic properties of the VE damper. The influences of mechanical and structural parameters on the stiffness characteristics of the device are investigated through static analysis. The nonlinear dynamic equations of the vibration isolation system with the proposed device are established. The effects of the system parameters on the frequency-amplitude responses and absolute displacement transmissibility are numerically discussed. The isolation performance of the proposed device is compared with that of the isolator, which only consists of a VE damper. The results show that the VE low-frequency vibration isolation and mitigation device can effectively reduce the initial isolation frequency and broaden the isolation frequency interval. The proposed device can obtain better low-frequency isolation and mitigation performance by reasonably designing the device parameters.