A Variable Inertance Damper:Experiment And Mechanical Model

In recent years,the span of the cable-stayed bridge has continued to increase,resulting in the continuous increase of the length of the main force-transmitting components of the cablestayed bridge.Under the excitation of wind,rain,vehicle-bridge coupling,etc.,a series of unconventional vibration forms appear,mainly manifested in high-order multi-modaldominated vibration under wind excitation and ultra-low frequency reciprocating tensile vibration under the action of heavy traffic.The damper has been unable to effectively control the unconventional vibration of the damper.In the field of structural vibration control,the inertial mass damper has received extensive attention from all walks of life since it was proposed.It generates an inertial mass that is many times larger than itself through rotation,and can provide the same vibration reduction effect as the real mass.It is widely used in Control the vibration of structures in engineering structures.The inertial mass of the inertial mass damper is realized by a mechanical device,which can generate an inertial mass force proportional to the relative acceleration at both ends,but the inertial mass provided by the traditional inertial mass damper under the action of external excitation is basically fixed,and it is difficult Effectively controlling the unconventional vibration of the stay cable and adjusting the inertial mass of the inertial mass in an effective way are the focus of attention from all walks of life.In this paper,a new type of variable inertia mass damper device is proposed to convert the linear motion of the stay cable into the rotation inside the damper through the roller screw.Combined with the current control electromagnetic clutch to realize the differential speed,the damper mass block is changed.The acceleration at both ends in turn changes the magnitude of the inertial mass.Under the action of the external excitation,the equivalent inertial mass of the damper is changed under the control of the current.The variable inertial mass damper outputs different damping forces.The main research contents include:1)Design variable inertia mass dampers.Three schemes of variable inertial mass are conceived.Through scheme comparison,the method of hysteresis clutch in electromagnetic clutch is used to realize variable inertial mass.The working principle of variable inertial mass device is briefly described.Mechanical model and angular velocity model of mass.2)Collect and analyze damper test results.Formulate the test plan,carry out the mechanical test according to the design and process the damper,draw the curve through the collected test data,and analyze the displacement lag of the variable inertia mass damper under the different external excitation frequencies and amplitudes of the damper under the condition of electrification and non-electricity The slope of the loop curve and the variation law of the peak value and frequency of the energy consumption and the angular velocity of the mass block.3)Study the damper parameter law.Combine the mechanical model,angular velocity model and test results,identify the parameters of the mechanical model,verify the accuracy of the identification of the initial inertia of the linear parameters and the friction force,analyze the variation law of the equivalent inertia of the nonlinear parameters,and establish the currentangle The functional relationship between acceleration and equivalent inertia,and the energy dissipation capacity of equivalent inertia is studied,and realize the linear change of equivalent inertia through simulation.