A magnetorheological elastomer-based hybrid vibration isolation system with semi-active control and quasi-zero stiffness performance

The quasi-zero stiffness (QZS) vibration isolation system suffers from conflicts between low-frequency and mid-to-high-frequency isolation, despite having outstanding low-frequency vibration isolation performance. Meanwhile, the semi-active control technology based on magnetorheological elastomers (MRE) can achieve good vibration isolation effects over a wide frequency range. However, its ability to isolate low-frequency vibrations is still restricted. To address the challenge, this paper proposes a hybrid vibration isolation system that combines QZS isolation technology with semi-active control technology based on MRE. The hybrid vibration isolation system consists of the QZS vibration isolation unit and the semi-active control unit. The inclined springs provide negative stiffness, while the MRE and linear vertical spring jointly provide positive stiffness. The magneto-mechanical properties of the MRE samples are analyzed, and a phenomenological constitutive model is established. The relationship between the magnetic field and control current in the hybrid system is determined through electromagnetic field simulation. The hybrid system's vibration isolation performance in passive mode as a QZS isolator with nonlinear damping properties is assessed using the harmonic method. The hybrid system's vibration isolation performance under random and harmonic excitations is then examined in semi-active control mode. The findings demonstrate that the hybrid system outperforms traditional QZS isolators in terms of vibration isolation performance in passive mode. Furthermore, it demonstrates excellent performance in the semi-active mode under both harmonic and random excitations, with good wideband low-frequency vibration isolation capabilities.