A novel magnetorheological fluid-elastomer vibration isolator

In this study, the performance of a new design concept, utilizing a magnetorheological (MR) material encapsulated in an elastomer matrix, is investigated. Two different MR materials are used; an MR fluid, and an MR grease. To examine the MR fluid-elastomer (MRF-E) a characterization device is built, with which each prototype is tested. In addition; an MRF-E vibration isolator device is designed and fabricated and the dynamic performance is studied under harmonic oscillatory vibrations for a wide range of frequencies and various applied magnetic fields. Moreover, a theoretical work is conducted by proposing a three-element phenomenological model for replicating the dynamic behavior of the MRF-E device under sinusoidal loadings, and the results are compared with the experimental data. In order to further evaluate the effectiveness of the MRF-E vibration isolator for vibration control, a single degree-of-freedom (SDOF) system incorporated with this device is developed. Theoretically, the equation-of-motion, utilizing the proposed phenomenological model, is derived to provide performance predictions on the effectiveness of the semi-active device at suppressing unwanted vibrations. Experimentally, a SDOF system, constrained to rectilinear motion, composed of a mass, four linear springs, and the MRF-E vibration isolator is then designed and manufactured.; The material characterization experiment demonstrates how both the viscoelastic properties and the damping and stiffness capabilities of the new MRF-E prototypes can be controlled by an applied magnetic field. The experimental results for the MRF-E device exhibit how both the stiffness and the damping capability of the MRF-E vibration isolator are functions of the displacement amplitude and magnetic field strength, and only weakly dependent upon the frequency of excitation. From the results of the experimental investigation on the dynamic performance of both the MRF-E prototype and the vibration isolator device, under different harmonic oscillatory motion tests, it can be concluded that through an applied magnetic field one can control damping and stiffness characteristics over a wide range of frequencies and displacement amplitudes. The proposed nonlinear phenomenological model has demonstrated to be a valuable aid in the prediction of the performance of the MRF-E vibration isolator in a SDOF vibration system.; This work verified how the proposed novel MRF-E vibration isolator is capable of attenuating undesirable system vibrations for a range of small displacement amplitudes and frequencies.