Research On A New Structure Of Magnetorheological Damper

In recent years,Magnetorheological(MR) damper has been developt rapidly as an ideal semi-active damping control device. With the advantage of adjustable damping characteristics, a wide range of damping force adjustment,easy to implement real-time control and so on, the MRD has been shown a good prospect in seismic, vehicle suspension system,offshore platform vibration,the resistance of wind vibration of cable-stayed bridge.The main contents of this thesis include:(1)A structure of MRD used on vehichel suspension is designed in this paper and manufacture six different damping gap prototypes.The sizes of Damping gap are 0.3 mm, 0.5 mm, 1.0 mm, 1.25 mm, 1.5 mm and 2 mm.The MRD includes magneto-rheological fluid(MRF) chamber, storage chamber, the piston assembly and the coil assembly. The coil assembly and the damping gap are on the piston.The lower part of the MRD is the accumulator chamber,which equipped with nitrogen that can replenish the volume of the cavity when the MRD works.(2)We manufactured six different damping gap of MRD and made the tension and compression test.The Machinetest of the test is the HT-9711 Dynamic Testing Machine.The inputting excitation signal are triangular signal and sinusoidal signal to know the effects of the damping gap,the frequency,the current,the speed on controllable force.This dose the experiments for the applications of the 1/4 for vehicle semi-active suspension HIL test bench and vehicle suspension performance test bench.(3)Though the MRD used on vehichel suspension that has been messioned above can meet the needs of the bench,it has some shortcomings.To solve these problems, we propose a MRD of multi-hole external damping channels. The outside of the magnetorheological fluid chamber set uniform holes as damping channel.So the magnetorheological fluid flows through large area,The new type of MRD has the characteristics of small damping force with zero magnetic field conditions.At the same time,by providing a plurality of electromagnetic coil assemblies,the damping force can be increased under the condition of magnetic field,and this has the advantage of a wide range of damping force adjustment.(4)Bingham model is simple and convenient to express the damping characteristics of MRD.Therefore,based on the Bingham model,we do the quasi-static analysis of the new type of MRD.Derived the pressure gradient equation of the new type of MRD and its analytical solution Solution. Finally,the obtained theoretical solution is verified by example.Contents of this paper with some guidance and reference provides a theoretical basis on the practical application of MRD.