Design Of Variable-Stiffness Vibration Isolation System Based On Magneto-rheological Elastomer And Study Of Its Vibration Reduction Performance

With the development of science and technology, the precision machinery industry demandsbetter and more quiet surrounding environment. Vibration isolation is a most effective vibrationprotection method. The stiffness of vibration isolators in existing conventional type of vibrationisolation system is usually of fixed value. This limits the system in exhibiting its vibration isolationeffect in that, it has poor results for lower frequency vibration, especially for resonance frequency.Magneto-rheological elastomer (MREs) is a new branch of magneto-rheological materials. It hasboth advantages of magneto-rheological fluid and elastomer, and it’s more stable and controllablethan the magneto-rheological fluid materials. It’s an intelligent materials in that it’s shear moduluscan be controlled by a magnetic field. It has wide application prospects in the vibration control area.This thesis first applied a material preparation method based on the present situation of MREpreparation. It then prepared a batch of different content-proportions of MRE samples with gooddensity distribution. The samples were subsequently tested for their dynamic mechanical properties.Based on the vibration isolation principle and the stiffness and damping model of magneto-rheological elastomer, the thesis analyzed the principle of magneto-rheological elastomer variable-stiffness vibration isolator. It then proposed using adjustable stiffness of magneto-rheologicalelastomer vibration isolation for the vibration isolation system. By changing the current ofvibration isolator’s coil to control the shear modulus of magneto-rheological elastomer, it canadjust the stiffness of the isolation system, making the system obtain wider vibration isolationfrequency range. The systems were designed with both single and double isolators and byemploying SimuLink software to analyze the vibration isolation system, it was found that such adesign is effective and applicable.On this basis, we designed a test rig to study the damping performance of the magneto-rheological elastomer variable-stiffness vibration isolation system. Through testing the dynamicscharacteristic of vibration isolator we found that its natural frequency can be shifted. This provesthat the isolator can reduce vibration and the MRE’s stiffness is adjustable.Further on, the vibration response of the isolation system was tesed in different conditions,which showed that, through changing the magnetic field the isolation coefficient and vibrationpeak can be effectively reduced. This confirmed that the design of magneto-rheological variable-stiffness vibration isolation system has excellent vibration reduction performance.