Research On A Magnetorheological Damper With Parallel Multiple Annular Ducts

Magnetorheological(MR)damper is a novel controllable device,because of their mechanical simplicity,quick in response,large dynamic range and small energy consumption,this class of devices has been widely applied to the civil structure systems against severe earthquake and vehicle suspension systems and the resistance of wind vibration of cable-stayed bridge.The paper concerning the MRD with the parallel multiple annular ducts includes the following three parts:(1)The parallel-plate model of the magnetorheological dampers with single annular duct and parallel double annular ducts are established.The analytical solution of the damping force is solved by the equations of the damping force of two magnetorheological dampers.At last,the damping force of the magnetorheological damper with the parallel multiple annular ducts is discussed.the calculation results and experimental results prove that compared with the magnetorheological dampers which have single annular duct,the magnetorheological dampers with two parallel annular ducts can decrease the damping force obviously when there is no magnetic field and the damping force decreased little under the magnetic field and the feasibility of the structure of the MRD which have parallel multiple annular ducts is verified.(2)In view of the defects in the common structure of MRD,a structure of the MRD which have parallel multiple annular ducts is designed in this paper.The MRD includes piston rod,cylinder cover,cylinder,the piston assembly,floating piston and cylinder bottom.In the movement of the piston assembly in the cylinder,the controllable rheological properties of Magnetorheological fluid through the parallel multiple annular and generate the damping force.According to the structure design of the MRD which have the parallel multiple annular ducts,two kinds of experimental MRD are designed,which have single annular duct and parallel double annular ducts.Through the analysis of the measured data,it can be seen that the MRD withparallel double annular ducts can effectively improve the adjustment range of the damping force.(3)A two degree of freedom quarter vehicle model is established,and the MRD is applied to the automobile suspension system.The control effect of seat accelerations,suspension travels,and type dynamic loads of passive control,ideal skyhook control and On-off control of the magnetorheological semi-active suspension of each mode are compared by simulation and the influence of damping coefficient of MRD at zero magnetic field on the effect of semi-active control is analyzed,computation results prove that the magnetorheological semi-active suspension can effectively improve the riding comfort.The conclusions of the thesis have important reference value to the design of the structure parameters of MRD and the research of magnetorheological semi-active control system.