Analysis and design of a semi-active X-structured vibration isolator with magnetorheological elastomers

Abstract

This paper proposes a semi-active X-shaped vibration isolation (XSVI) system with magnetorheological elastomer (MRE) based on its field-controlled variable properties. The conceptual design of the proposed system is constructed by embedding an MRE-based device into a X-shaped structure, instead of the original XSVI’s linear spring. The proposed system could fulfill tuning capability stiffness for effective vibration mitigation in random low-frequency excitations. The theoretical modeling is developed and the static analysis of the proposed MRE-based XSVI system is studied. The dynamic equation of proposed isolation system is established and solved by harmonic balance method. The influence of key geometrical parameters and field strength on the proposed system characteristics are detailly studied and discussed, and the tunable frequency-shift properties are presented. Under the harmonic excitations in a single frequency, the displacement of the isolated objective can be reduced by 22.5% with the field strength of 0.7 T. In the presence of double-tone (2 Hz mixed with 5 Hz) external loading, the reduction ratio of excited and isolated objectives’ displacements by semi-active control are respectively 63.95% and 18.77% by comparing the passive-off state. Additionally, compared with the original XSVI system and MRE isolator, the proposed MRE-based XSVI system in semi-active controller presents outstanding isolation performances. This study indicates that the proposed MRE-based XSVI system could provide a potential method for vibration isolation tuning in wide-band low-frequency range.