Design Of Variable Stiffness Isolator Based On Magnetorheological Elastomer And Performance Study

In industry,the impact of vibration can not be ignored,and vibration isolator has become an important tool for vibration reduction.Vibration isolators are widely used in various fields,it is developed in the field of aerospace and shipping.Magnetorheological elastomer,as a new type of smart vibration isolation material,has a great potential for development.The purpose of this paper is to design a magnetorheological elastomer intelligent isolator,which can be applied to ships and other fields.Based on the good compression performance of elastomers,a magnetorheological elastomeric isolator with variable stiffness has been designed,and the dynamic performance of the isolator has been tested.The specific work is as follows:First of all,the preparation and performance test of magnetorheological elastomer are carried out.The magnetic circuit of the elastic system is designed and calculated by the principle of magnetic circuit design,and the magnetic circuit is simulated with the JMAG software.The results show that the magnetic circuit design results can meet the need of 1T magnetic intensity.Then,a set of preparation device which can make different thickness,shape and material under field conditions can be obtained.Next,from the perspective of magnetorheological elastomer preparation process,three kinds of magnetorheological elastomers with different matrixes were prepared by using the preparation device,and then the self-made testing device was applied to test the modulus of elasticity of the elastomers on universal material testing machine.Finally,the compressive modulus and the magnetorheological effect strength of different magnetic fields and dependent variables are obtained.Next,the magnetic circuit of the isolator is designed and simulated by combining the theory of electromagnetics with the finite element simulation.And according to the calculation results,the size of each part of the vibration isolator structure and the number of winding turns are determined.The final result of the design shows that when the 2A current is loaded,the magnetic strength at the elastic place in the isolator can reach 0.9T,which meets the design requirement.Thirdly,the dynamic mechanical model of the variable stiffness magnetorheological elastomer isolator is established.The micro mechanical model of magnetorheological elastomers were studied,exploring the compression modulus characterization of materials and the impact of material magnetorheological effect.Meanwhile,the macroscopic mechanical model of magnetorheological elastomers is studied.The viscoelastic properties and nonlinear hysteresis characteristics of materials are studied,and the performance of vibration isolators is predicted.Finally,the compressive modulus and the magnetorheological effect strength of different magnetic fields and dependent variables are obtained.Finally,the performance of the variable stiffness magnetorheological elastomer isolator is tested.Under the conditions of different current,frequency and amplitude,the vibration isolator is placed on the Instron8801 electrohydraulic servo fatigue test machine to carry out dynamic mechanical test.The whole change process shows that the equivalent stiffness of the whole isolator will gradually increase with the current increasing,and the characteristic of variable stiffness is realized.In addition,the change of amplitude and loading frequency also affect the damping characteristics of the isolator.Then based on the test data,the parameters of the model are identified by Simulink simulation,and the parameters of the dynamic model are determined.The results show that the model can better reflect the performance of the vibration isolator.