Simulation Analysis Of Flutter Of A Linear Motor Of Metro Vehicles

The linear motor-driving wheel rail transportation system is an advanced mode of transportation tools all over the world.It has a strong climbing ability,a good adaptability for small curved stacks,a small cross-section size,and a good performance of curve negotiation;It is especially applicable as traffic rail transit for large and medium-sized cities.However,it is found that the linear motor-driving rail vehicle is easy to flutter when the vehicle is driven,which seriously hinders the development of the linear motor technology.in the engineering practice.Linear motor flutter may also cause some problems.For example,the linear motor suspension system makes serious noise,the linear motor and the induction plate friction leads to burning damage of the linear motor.The flutter problem of the linear motor has seriously affected the application of the linear motor in the rail transit,so the research on the mechanism of flutter of a linear motor has a strong industrial application value.In this paper,a finite element model of the linear motor is established,and the geometric constraint and load force of the linear motor are considered in the model.The model is set up and simplified,and the simulation is carried out.The following conclusions can be drawn:(1)A single-degree-of-freedom model of the linear motor is established,and a simple mechanism analysis is carried out.It is found that the electromagnetic traction force of the linear motor decreasing with the increase of the speed can cause the traction chatter of the linear motor.(2)A finite element model of the linear motor is established,The vibration mode of the model is analyzed.It is found that the model frequency is close to that of the actual linear motor system,which suggest that the simulation result has been validated.(3)The transient dynamic analysis of the linear motor finite element model is carried out.The linear motor traction state and the inert state are simulated and analyzed.It is found that vibration of the linear motor is excited in the traction state and the vibration is small in the inert state.Flutter phenomenon occurred in the traction state.(4)The influences of the rubber stiffness,the running speed of the linear motor,the lateral bar and the vertical force on the vibration of the linear motor are analyzed.It is found that the greater the stiffness of the rubber node,the greater the natural frequency and;the more intensive the vibration.The linear motor horizontal rod can greatly reduce vertical and lateral accelerations of the linear motor.There is a coupling phenomenon between the vertical vibration and lateral vibration of the linear motor.The vertical force of the linear motor can aggravate vibration of the motor.