Research On Structural Vibration Control Based On New Extrusion Built-in Valve MR Damper

In civil engineering and other related fields,vibration,shock and earthquake disasters have always been the focus of attention,and the focus of the research is to ensure the normal use of the building structure by considering the building structure to reduce the influence of these effects.As an advanced control device,the semi-active control device has many advantages,such as relatively low power consumption and active control device,which can produce relatively large damping force,fast reaction speed and flexible control,and simple design of structural components.However,the current magneticrheological dampers are assembled according to a single working mode,and the output in the actual building structure is very large,and the general magneticrheological dampers provided by the damping force is relatively limited.Therefore,it is important to design an MR damper for different engineering requirements.For the shortcomings of existing MR dampers,A new MR fluid damper with mixed working modes and large output,For the derivation of its mechanical model,The magnetic force line distribution and magnetic field strength inside the damper were analyzed using ANSYS Maxwell simulation software,Then,the distribution of magnetic field strength in the fluid circulation channel and the distribution of magnetic field strength in the fluid flow channel are studied;Bring the derived mechanical model of MR damper into the isolation structure for time course analysis,Verify the effectiveness of the MR damper;Finally,the performance test of the hydraulic servo actuator,This will then be compared according to the theoretically derived mechanical model and the experimental data.The main research contents of this paper are as follows:(1)A new type of magneticrheological damper with various working modes and considerable output is proposed.The internal structure,size parameters and materials used of the damper are analyzed,and the mechanical model of the magneticrheological damper in each working mode is derived.Finally,the size parameters of each structural member of the damper,the size of the liquid circulation channel are determined to be 2mm,and 10 # steel is selected as the magnetic conductive material and 304 stainless steel is selected as the magnetic insulating material.Moreover,and the mechanical model of the damper in different working modes is obtained.(2)Conduct the electromagnetic field simulation of the magnetic rheological damper proposed in this paper,test the internal magnetic field strength and magnetic induction line distribution,and verify the feasibility of the magnetic rheological damper structure.The hear valve and extrusion valve are were analyzed analyzed using ANSYS Maxwell software.The analysis shows that when the excitation current increases from 0.5A,1.0A,1.5A and 2.0A,the magnetic field strength in the main liquid circulation channel of the magnetic rheological damper increases with the increase of the magnetic field direction can reach more than 1.0T,which can easily meet the maximum yield strength of the MR fluid by 0.5T.Under the extrusion valve type,the average magnetic induction intensity in the extrusion channel can reach about 0.3T,making the MR fluid achieve a certain degree of magnetization in the extrusion channel,thus proving the rationality of the structure.(3)The specific size parameters of the new magnetic rheological damper are brought into the deduced mechanical model,so as to obtain the mechanical model of the magnetic rheological damper with the current and the piston motion speed as the control variables.Using the mechanical model,the five-layer isolation structure after the scale,the classical optimal control limit Hrovat optimal control semi-active algorithm,the control effect of the displacement of three seismic waves is over 74% and 35% respectively,so the study can better control the displacement and acceleration response of the structure.(4)Mechanical characteristics of the magnetic rheological damper in this study.The hydraulic servo actuator studies the actual influence by the control variable method,and compares the theoretical mechanical model with the test results.The test results show that when the current is 0A,the amplitude is 10 mm and the frequency is 0.4Hz,the maximum output damping force of the damper is 300 N.When the input current is 1.0 A and the amplitude is 10 mm,the output damping force will reach 10,000 N in the frequency.When the current is introduced,the reason for the difference between the theoretical damping force of the damper and the test damping force is the increase of the current strength,and the pressure drop of the liquid circulation channel in the piston of the damper changes greatly,which leads to the friction between the magnetic rheological fluid and the piston fluid circulation channel,thus producing different results from the theory and practice.The new MR damper has large and stable mechanical properties,and its output is basically consistent with the design target.