Design And Performance Study Of Damper Based On Magnetorheological Elastomer

Since the concept of structural vibration control has been introduced into the field of civil engineering,researchers have proposed a variety of damping control methods for the dynamic response of building structures under earthquake action.Semi-active control has become one of the new development directions in the field of building structure damping control due to its advantages of low energy consumption,high efficiency,easy maintenance and obvious effect.Magnetorheological elastomer material is a new type of smart material that has been developed in recent years to achieve semi-active control technology.Its stiffness can be continuously and rapidly changed with the change of the applied magnetic field,and at the same time overcome the shortcomings of magnetic particles in the magnetorheological fluid,such as easy sedimentation,high wear rate and instability,and the application prospect is very considerable.In this paper,the research on magnetorheological elastomers is carried out.From the sample preparation and mechanical properties test,a magnetorheological elastomer damper which can be used for damping control of building structures is designed.The main research work of this paper is as follows:(1)According to the working performance of the extruded magnetorheological elastomer damper,combined with existing test materials and test conditions.Using a silicone rubber as the matrix material,carbonyl iron powder as the magnetic conductive particles and silicone oil as additives,a magnetorheological elastomer was prepared under field conditions.And tested the static and dynamic mechanical properties in compression mode.The test results show that the relative magnetorheological effect of the magnetorheological elastomer is 92.94%when the applied magnetic field strength is 800mT.(2)From the perspective of microscopic physical model,the reason is analyzed theoretical-ly that the magnetostrictive modulus and magnetostrictive force of magnetorheological elasto-merr increase with the increase of magnetic induction intensity.And combined with the mecha-nical model of general viscoelastic materials,the macroscopic mechanical model of magnetorh-eological elastomer is established.By fitting with the mechanical property test data,the relationship between the magnetostrictive modulus of the magnetorheological elastomer and the magnetic field strength is obtained as follows:E=1.9583B?3-4.0982B?2+4.1977B+1.87.(3)A variable-stability squeezed magnetorheological elastomer damper was designed independently,and the magnetic circuit of the damper was theoretically calculated according to the basic principle of magnetic circuit design.The calculation results show that when the 1400za copper core with an diameter of 0.55 mm is wrapped around the excitation coil,the magnetic induction intensity generated by the direct current of 2A can fully meet the working requirements of the magnetorheological elastomer.The magnetic saturation analysis of the magnetic circuit of the damper is carried out to verify the validity and rationality of the designed magnetic circuit.(4)The finite element simulation analysis of the magnetic circuit in the self-designed magnetorheological elastomer damper was carried out by ANSYS finite element analysis software.The analysis results show that when a current of 2A is applied in the form of current density in the exciting coil,the magnetic induction intensity acting on the magnetorheological elastomer is 0.91T,which can fully satisfy the 0.8T required when designing the damper.It is proved that the magnetorheological elastomer in the damper can exert the maximum magnetorheological effect.