Research On Magnetorheological Elastomer And Intelligent Insulator For Composite Working Condition

The traditional base isolation system is most widely used in civil engineering structures to realize the seismic mitigation, but because of its damping and stiffness cannot be adjusted with the change of the external load, so the building will be destroyed when the earthquake frequency is beyond the scope of design even if there is an isolation system. In the future, the development of semi-active control isolation system is the main research for building seismic isolation. The main feature of magnetorheological elastomer is that its stiffness and damping can be changed and recovered in real time and reversible control under applied magnetic field, these advantages make it widely used in seismic isolation. However, the practical application of magnetorheological elastomer is limited because the contradiction between the magnetic rheological effect and the mechanical properties, and the relative low permeability.In this paper, a high performance magnetorheological elastomer was prepared by improving the ratio of materials and preparation process, and tested its properties. On the basis, a magnetorheological elastomer vibration isolator was designed used for compound condition, and its properties were verified by simulation. The specific work is as follows:(1) The combination of coil and permanent was designed to produce magnetic field, and its feasibility was verified by using ANSYS. The high performance magnetorheological elastomer based on silicone rubber were obtained by improving the ratio of materials and optimizing preparation technology.(2) Based on analyzing the relative permeability measuring principle, the relative permeability testing system of magnetorheological elastomer based on resonance circuit was built, and the factors which affect the relative permeability of magnetorheological elastomer have been studied experimentally, the relative permeability was up to 4.8. The factors which affect the mechanical properties of the materials are studied by the combination of theory and experiment, the magnetorheological effect of the sample with the content of 70% of carbonyl iron powder can reach 96% when the magnetic field strength was 400mT.(3) A vibration isolator based on magnetorheological elastomer was designed, the turns of coil was confirmed by theoretical calculation, and the rationality of the structure design was verified by simulation. The best number of layers of isolator was confirmed to optimize the structure of the isolator.(4) The dynamic model of the isolator was established according to the performance of magnetorheological elastomer and structure of the isolator. The stiffness, damping and maximum force of the isolator under different excitation amplitude, different excitation frequency and different control current were investigated by simulation. The results show that the isolator was suitable for lower frequency vibration, and its stiffness and damping can be changed by controlling the input current.