Mechanical Model Of Electromagnetic Inerter Damper And Study On Vibration Reduction Of Stay Cable

As the main force-receiving member of the cable-stayed bridge,the stay cable has the disadvantages of light weight,large flexibility and small damping.The stay cable is easy to generate large vibration under seismic load,wind and rain excitation,and parameter excitation,which greatly reduces the safety and service life of the cable stayed bridge.The damper can effectively reduce or suppress cable vibration caused by external excitation.However,the conventional damper has many disadvantages to reduce the energy consumption.Aiming at these shortcomings,this paper proposes a new type of damper,Electromagnetic Inerter Damper(EMID),which is used to analyze the mechanical properties and the cable-stayed vibration test.The main contents of this paper include:(1)This paper briefly introduces the vibration control and research background and status quo of cable-stayed cable stays at home and abroad,and clarifies the research content and research significance of the paper.(2)The basic structure of the electromagnetic inertier damper based on the ball screw as the core transmission device is introduced;Analyze its mechanical model,theoretical simulation and experimental analysis of the feasibility of the mechanical model;The effects of inerter,amplitude,external frequency and electromagnetic damping on the mechanical properties of EMID are analyzed.(3)The equation of motion of the cable-EMID system is established by differential equations;The complex eigenvalue method is used to obtain the analytical expression,and the analytical solution of the cable modal damping ratio is obtained.The optimal modal damping ratio corresponding to the non-dimensional damping coefficient of each mode is analyzed.(4)The energy equation is established by Hamlton principle to derive the equation of motion of the system.According to the optimal control principle,the linear quadratic optimal performance index is proposed to solve the optimal control force.Through the LQR control algorithm,fixed Q,change R obtains the relationship between the first three-order modal damping ratio and the weight coefficient R.The optimal damping coefficient corresponding to different inerter is obtained by the minimum of the norm.The optimal damping coefficient of different inerter of A10 cable of Dongting Lake Bridge is calculated.(5)The field test was carried out to analyze the damper damping effect of EMID under the simple harmonic excitation and free vibration on the cable and electromagnetic damping.