A semi-active quasi-zero stiffness vibration isolator based on magnetorheological elastomer with a fast convergence switch control

Abstract

Quasi-zero stiffness (QZS) isolators have attracted extensive attention due to their high-static–low-dynamic stiffness. The effectiveness of the traditional QZS (T-QZS) isolators to attenuate low-frequency vibration has been extensively studied. The T-QZS isolator, however, cannot usually provide satisfactory vibration mitigation performance under ultra-low frequency excitation. To tackle this challenge, we propose a semi-active QZS isolator featuring magnetorheological elastomer (SAQZS-MRE isolator). The prominent merit of the proposed design is that the applied MRE material can provide varying stiffness and damping to the proposed SAQZS-MRE isolator, making the isolator suitable for vibration isolation under wide-band low-frequency range. The dynamic viscoelasticity properties of the MRE are experimentally characterized, to formulate the dynamic modeling of the SAQZS-MRE isolator. The open-loop vibration isolation characteristics of the SAQZS-MRE isolator are assessed using the harmonic balance method (HBM). Subsequently, two semi-active control strategies including skyhook and fast convergence switch (FCS) are effectively utilized in the proposed SAQZS-MRE isolator to evaluate their closed-loop performance. The results demonstrate that the SAQZS-MRE isolator with FCS control can eliminate the resonance peak and reduce the initial isolation frequency. In the higher frequency range, it can also improve the vibration isolation performance compared with the SAQZS-MRE isolator with passive control.

Adaptive beam with elastic support based on magnetorheological elastomers for modal modulation and vibration suppression

“…An MRE isolator with a periodic configuration [22] for target frequencies was adapted to achieve vibration attenuation in controllable bandgaps. A semiactive QZS isolator [23] with controllable stiffness and damping was proposed to achieve low-frequency vibration suppression over a wide bandwidth. A hybrid MRE-DVA containing a passive nonlinear absorber [24] was adopted to broaden suppression bandwidth through the dual transformation of natural frequencies.…”

A bidirectional-controllable magnetorheological elastomer-based quasi-zero-stiffness isolator

“…Additionally, under varying load conditions, the BI-QZS can maintain the quasi-zero point in combination with a feedback control strategy to control the applied current. Lin [47] proposed a QZS isolator utilizing shear-mode MREs in theory, and the adjustment principle was verified by simulation. However, the use of shear-MREs poses risks due to insufficient load-bearing capacity [48].…”

Experiment and analysis of drop-weight damping control of MR semi-active impact resistance-based hydraulic actuator

“…Xu et al [27] proposed a semi-active pseudo-negative stiffness control strategy based on MRD to solve the problem of low damping output in cable ties vibration control, and showed the advantages of better high damping efficiency of the proposed controlled model. Lin et al [28] designed a semi-active isolator with MRF to solve the problem of underdamped performance of conventional isolators, and improved the vibration isolation performance at both low and high frequencies. Jiang [29] designed a mechanical leg structure using MRF combined with torsion springs and proved that MRD could effectively improve the environmental adaptability of the robot.…”