Research On Magnetorheological Fluid Damper Damping Force Based On Internal Flow State Of Damping Channel

Because the magnetorheological fluid damper has the characteristics of fast response speed and large output damping force,it can greatly exert the advantages of semi-active vibration control.Therefore,magnetorheological fluid dampers are widely used in high performance semi-active vibration control systems.At present,the mathematical model of magnetorheological fluid damper based on internal mechanism analysis is only suitable for describing the output characteristics of the magnetorheological fluid damper under a certain motion state in the damping channel.When the motion state of the fluid inside the damper channel of the magnetorheological fluid damper changes continuously,the mathematical model obtained under the condition of the flow field is no longer suitable.To achieve high performance semi-active vibration control,the output damping force of the magnetorheological fluid damper needs to reach the optimal control force.If the mathematical model of the magnetorheological fluid damper is not accurate enough,the output damping force of the magnetorheological fluid damper cannot quickly reach the optimal control force.When performing high-quality vibration control of complex controlled objects,the vibration control system obtained by using the original mathematical model of magnetorheological fluid damper has the risk of failure.In view of the above problems,it is of great significance to establish an accurate mathematical model of magnetorheological fluid damper.Therefore,based on the relationship between the internal flow state of the damping channel and the piston motion state,the mathematical model of the magnetorheological fluid damper is studied and analyzed for a typical structure of the magnetorheological fluid damper.Firstly,the theoretical analysis of the relationship between the magnetic field distribution in the damping channel of the magnetorheological fluid damper and the given control current is carried out by electromagnetic field theory and the more accurate distribution of the magnetic field is studied by Maxwell finite element simulation tool.Then using the actual measured rheological fluid yield stress data,the quantitative relationship between the yield stress and the control current of the magnetorheological fluid in the damper channel is obtained.Secondly,through the fluid correlation theory,the output damping force of the magnetorheological fluid damper under various motion conditions is analyzed.The expressions of the output damping force of the magnetorheological fluid damper under different control currents and different control currents are obtained,and the relationship between the internal flow state of the damping channel and the piston motion state is studied.Subsequently,this paper builds a unified damping force calculation model that can automatically determine the internal flow state of the damping channel by the motion state of the piston to match the expression formula of the appropriate output damping force in the simulink software.In order to verify the correctness of the mathematical model,this paper designs a multi-functional loading test-bed,and introduces its structure,principle and design.Finally,by comparing the actual data with the simulation data,the mathematical model of the magnetorheological fluid damper based on the internal flow state of the damper channel is verified.The results show that the mathematical model can well describe the actual output damping force of the magnetorheological fluid damper.