Analysis On Rheological Mechanism Of Magnetorheological Elastomer And Experimental Study

Magnetorheological elastomer(MRE) is a new kind of smart materials whose rheological properties can be controlled rapidly by the external magnetic field.It is mainly composed of rubber and micron-sized ferromagnetic particles,which forms a chain-like structure. Therefore its mechanical, electric and magnetic properties can be changed by the applied magnetic field, which is called as the magneto-induced effect. But this effect is not remarkable enough currently for the engineering application. So it is important for material preparation to optimize parameters to enhance the magneto-induced effect. MRE have the features of no sealing, stable performance, quick response and so on. MRE Isolation buffer has low energy consumption, simple configuration,good reliability and wide operation bandwidth compared with traditional isolation buffer. In this paper, rheology mechanism of the MRE material, a new kind of compound structure was constructed, can help overcome the phenomenon of the magnetic flux leakage, to extent to improve the utilization rate of the magnetic field. The system of MRE isolation stent was designed, The related experimentals were experimentally explored in this work to verify the analyzed theoretically conclusions. The specific works are as followed:â‘ Based on the magnetomechanics, the microstructure of chains consisting of polarized particles, and the interaction between particles, the shear stress distribution contributed by a single chain of polarized particles is formulated, and then the yield stress of magnetorheological elastomer is obtained under the assumption that the distribution of chains tends normally. The effects of the applied magnetic field intensity, the size of the particles, and the volume fraction of the particles on the macroscopic yield stress are analyzed. The proposed model is capable of analyzing the effects of other influencing factors on the yield criterion of MRE, which may assist the design and development of high-performance MRE. Finally, by using the dynamic mechanical analyzer (DMA), the magneto-induced shear storage modulus of MRE sample are tested at different magnetic field and the experimental and the results verify the rationality of physical model.â‘¡A new kind of the macroscopic viscoelasticity parameter model was described the mechanical performance of MRE is proposed, the magneto-induced shear modulus, loss modulus of MRE are calculated on the basis of above model. By using the improvement dynamic mechanical analyzer (DMA), the magneto-induced shear storage modulus, loss modulus of MRE sample are tested at different magnetic field and frequency and the experimental results implicate the rationality of the viscoelasticity model.â‘¢A new kind of compound structure of magnetorheological elastomers(MRE) was designed to improve the field-dependent properties of MRE, to avoid the flux leakage, to increase the utilization ratio of the magnet and make the application equipments easy and light. A shearing stress-strain experiment for the compound structure was carried out , the results verify that this kind of compound structure of magnetorheological elastomers(MRE) has a good control.â‘£Based on the related theories and the compound structure of magnetorheological elastomers(MRE), a system of isolation stent based on MRE was designed and its isolation principle was analyzed. A single degree of freedom vibration isolation stent system was built in the vertical direction, and the experimentions were carried out.The experimention shown that the vibration isolation effect was very significant.