The Research On The Influence Of Active Parameters Of Yaw Damper On EMU Dynamic Ability

With rapid development of the high-speed railway in our country, the increasing number of high-speed EMU has been put into service. Must ensure The running stability, riding quality and curving performance. Yaw damper connect the frame and the car body, which is an important part of suspension system, and it consists of an oil storage cylinder, a piston, a piston rod, throttle valve system with many components, reasonable yaw damper parameters is a key factor to ensure the stable operation of the high speed vehicle. Traditional vehicle system dynamics simulation analysis make the yaw damper characteristics equivalent to linear spring and dampers in series structure and practical application by the influence of shock absorber valve body structure and oil properties, damping and nonlinear, making traditional dynamic simulation results and the actual dynamic performance has certain difference.Based on the working principle of the yaw damper and the structural characteristics of the valve body, combined with the theory of hydrodynamics, damping characteristics of the yaw damper is analyzed, and a simulation model of the yaw damper is built by modeling and simulation platform AMESim. The effects of the change of excitation amplitude, excitation frequency, damper structure parameters and oil parameters on the damping characteristics of the damper are analyzed. According to the structure parameters of high speed EMU trailers, used the multi-body dynamics simulation software SIMPACK to build the vehicle system dynamics simulation model. By connecting the yaw damper simulation model and vehicle dynamics simulation model, to achieve yaw damper characteristic parameters real-time exchange during the vehicle running process, according to the relevant standards, to analyze the dynamics performance of the vehicle.By the simulation and calculation of the vehicle dynamic performance under different operating conditions, the related dynamic performance indexes are obtained, and the simulation model is proved to be correct and feasible. Based on viscosity temperature characteristics of oil, analysis the influence of the viscosity of oil under different temperature on the vehicle dynamics performance, The results show that the absolute viscosity of oil at 20 C and 40 C has a minor effect on the stability and lateral stability of the vehicle. By the yaw damper for real-time damping and equivalent linear damping when the vehicle dynamics performance comparison, it is concluded that a higher critical speed and a better lateral stability of the vehicle with real-time damping. By the simulation analysis of the dynamic performance of the vehicle under different yaw damper failure conditions, the results show that the rotary damping torque of the yaw damper can significantly improve the critical speed of vehicle, yaw damper also has a significant impact on the operation stability of vehicles, and the difference of the dynamics under different failure conditions of yaw damper. Analyze effect of different joint stiffness of yaw damper on vehicle dynamic performance, the results show there is a suitable value of joint stiffness, too low or too high joint stiffness has a negative impact on vehicle dynamic performance.