| Magnetorheological vibration damping technology is a new type of intelligent vibration damping technology developed in recent years.It has attracted widespread attentions in the vibration control of vehicles,buildings and aircraft.Magnetorheological material is the core of magnetorheological vibration damping technology.Its mechanical properties can change rapidly and reversibly with the applied magnetic field,which makes the magnetorheological vibration damping device can adjust its working performance in real time to adapt to the changing working conditions.In this paper,the performance of damping material based on natural rubber was studied from three aspects: preparation method,theoretical model and multiphysics simulation.Magnetorheological elastomer damper and magnetorheological fluidelastic damper were developed and their mechanical property were tested.The main innovations of the paper are as follows:(1)Aming at the unavailable magnetic field,severe heat dissipation,time-consuming and labor-intensive operation and uneven force on the sample of the traditional vulcanizing device,a magnetic field device,a support device and a heating device was designed first.Then,an improved vulcanization device was developed,which provides a guarantee for the efficient preparation of magnetorheological elastomer(MRE).(2)Aiming at the problem that the mechanical property and the magneto-induced effect of MREs are difficult to balance,the effects of reinforcing agents,plasticizers and cyclic loading current on the properties of MREs were studied.The types of reinforcing agents and plasticizers with better performance were determined and the reason why the storage modulus of MREs decreases with circulating current loading was revealed.It shows an important guiding significance for the formula optimization design in the actual application of MREs.(3)Aiming at the problem that the micro-model of MRE deviates greatly from reality,a MRE chain cluster model was proposed based on the actual particle arrangement and the distribution of particle size and particle distance of the prepared MRE.The influence of temperature on saturation magnetization is introduced into the chain cluster model,so that it can reflect the temperature effect of MRE.By comparing the theoretical simulation results with the experimental test results,the correctness of the MRE chain cluster model was verified.The performance and its influencing factors of MREs can be predicted more accurately by the MRE chain cluster model,guiding the formula design and process optimization of MREs further.(4)Aiming at the vibration problem of missile Inertial Measurement Unit(IMU)during missile flight,MRE was applied to the vibration damping device and developed the MRE damper with the mechanical properties tested.The test results show that when the applied current is increased from 0A(0m T)to 2A(600m T),the stiffness change percentage can reach53.5%,which is conducive to improving the dynamic environment adaptability of the IMU.(5)Aiming at the problem of rotor vibration during helicopter flight,rubber elastomer and magnetorheological fluid(MRF)were used in the helicopter rotor damping damper simultaneously and developed the magnetorheological fluid-elastic damper with the mechanical properties tested.The results show that,when the loading current increases from 0 to 1.5A,the equivalent stiffness of the magnetorheological fluid-elastic damper increases from0.470 k N/mm to 2.881 k N/mm,the equivalent damping coefficient increases from0.021 k N·s/mm to 0.165 k N·s/mm.It not only meets the elastic stiffness(0.44 k N/mm)required by a helicopter rotor system,but also has good variable stiffness and variable damping characteristics. |
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