Research On Fluid-Solid Coupling Characteristics And Dynamic Control Of Air Springs In High Speed Trains

Recently,China's high-speed railway has developed rapidly.With the increase of the speed of railway vehicles,the technical requirements for the vibration reduction system of high-speed railways are becoming more and more strict.As the main vibration-damping component of the secondary suspension system of high-speed railway vehicles in China,the air spring has a significant impact on the running quality of the vehicle.China Standard EMU is a brand new product with completely independent intellectual property rights designed by China.This paper takes the ? air spring of China's standard EMU as the research object.The finite element model and the dynamic model are respectively established.And then,verify the accuracy of the model by routine experiment.The air spring model was used to simulate the influence of the diameter of the orifice on the stiffness and damping of the air spring.And taking advantage of the co-simulation model,based on the PID control strategy,the orifice diameter control is performed to reduce the vehicle stability index and improve the stability of the vehicle.The main research contents are shown as follows:(1)Taking the air spring of China's standard EMU as the research object,by establishing a finite element model,which considers the fluid-solid coupling characteristics between the airbag surface and air,analyze the relationship between the volume change law of the air spring and the pressure and the displacement of the cover plate.The curve parameters are fitted to provide a parameter basis for the establishment of the dynamic model.(2)Through the calculation of finite element model parameters,the law of volume and internal pressure is established.In AMESIM,an air spring dynamics model is established,and parameters are built into the model in the form of a formula to express changes in the internal parameters of the air spring.And through static and dynamic routine experiments on the standard EMU air springs,the experimental results are compared with the simulation results to verify the accuracy of the model.By changing the diameter of the orifice,the influence of the diameter of the orifice on the damping of the air spring system is obtained.(3)In the dynamics software SIMPACK,a high-speed train model is established.The stability of the vehicle was calculated.such as stability,ride comfort and safety of the vehicle(wheel-rail vertical force,axle lateral force,wheel weight-reduction rate,derailment coefficient,overturning coefficient).The results obtained meet the standard requirements and prove the rationality of vehicle modeling.(4)Using the joint simulation of AMESIM and SIMPACK,the air spring linear force element is replaced by the air spring dynamic model to analyze the stability,stability and curve pass ability of the whole vehicle.The results obtained meet the standard requirements,and the model can more accurately express the driving characteristics of the vehicle compared with the air spring linear force element.(5)Different vehicle speeds have different performances in the stability index under the same track disturbance.With different orifice diameters,the vehicle's stability index varies greatly.With the goal of reducing the vertical stability of the vehicle,the diameter of the orifice is adjusted.The fixed two-way proportional solenoid valve module in AMESIM is used to replace the fixed orifice module,and the PID controller is used to control the optimal diameter of the air spring orifice at different speeds.Through the analysis of the results,the level of stability is reduced by about 10%.It can achieve the purpose of improving the vertical stability of the vehicle.