Design And Experimental Study Of Fast Response Magnetorheological Damper

As a semi-active control device,magnetorheological(MR)damper,using MR fluid as working media,takes the advantages of wide-range adjustable damping force,low energy consumption and simple structure.It's widely used in the field of vehicle vibration reduction.However,the response time of the MR damper is long and the output damping force range of the MR damper is small,which is not conducive to the performance of its control and vibration reduction performance,resulting in poor grip performance of the wheels,and the vibration reduction performance is affected.In order to solve this problem,this subject combines the research of a certain type of car semi-active suspension system,through the design of MR damper,finite element simulation,experiment and other means,to study its damping characteristics and response time,design a large output damping force range,fast response MR damper.In this paper,according to the actual requirements of the vehicle,by analyzing the design principle of fast response MR damper,its structural form are determined,a plate model is established,and a formula for calculating the output damping force of MR damper is derived from the obtained plate model.A design study of MR damper was conducted.Combined with the formula of the output damping force of MR damper,the main structural parameters were initially determined,and the valve mode self-directed piston head structure,piston head and piston rod connection structure was designed.The design of seal guide structure solves the problem of seal guide of piston head and piston rod.Through the analysis of the properties of different materials,the material of each part of MR damper is determined.Based on the eddy current suppression study and magnetic circuit calculation,the specific technical means to suppress eddy current are obtained and the magnetic circuit parameters are determined.Simulation analysis of electromagnetic field of MR damper was performed.The two-stage magnetic circuit piston structure was found to be superior to the single-stage magnetic circuit piston structure through the analysis of different piston structures.The simulation analysis of different parameter values in the piston resulted in the optimal selection interval for different parameter values.By combining the selected parameter values and calculating the output damping force based on the formula,the theoretical damping force of MR damper is obtained,and the results show that the theoretical damping force range can meet the actual needs and verify the reasonableness of the design.Through the simulation analysis of different conductivity materials in the magnetic circuit,it is verified that the low conductivity materials effectively suppress eddy current generation and significantly improve the response speed of the magnetic field in the magnetic circuit.The components of the magnetic current damper are processed and assembled to obtain a prototype of the MR damper principle for experimental study.The damping characteristics for different currents and velocities were investigated by external characteristics test,and the results showed that the actual output damping force of the homemade MR damper is wide.The response time experiments were carried out to investigate the dynamic properties of MR damper at different step currents.The results show that the response time of MR damper is negatively correlated with the speed,and the response time is fast,which is significantly better than that of the commercial MR damper,and the design requirements for fast response are realized.