Study On Coupled Vibration Of High Speed Train Under Typical Wheel-rail Excitation

As we all know,railway transportation is the main artery of the national economy,which provides a great impetus to the healthy and stable development of the national economy.In recent years,with the increasing traffic density and traffic load,new materials and new technologies constantly being put into application,the running speed of the train can be improved.Thus a high-speed rail system is produced.High-speed railway has the characteristics of safety,comfort,speed and economy,and it has great advantages compared to other means of transportation.China's high-speed railway started late,but the rapid development of the current operating mileage has been ranked first in the world.The increase of the train speed makes the interaction between vehicle and track dynamic system intensifying and the deterioration of the environment.In order to ensure operation safety of high-speed railway,there is an urgent need to further study the interaction mechanism between train and track.In this paper,dynamics model of high-speed railway system is improved on the basis of previous research.This model is more consistent with the actual work of high speed train.And it has carried on the analysis of engineering example using the model,providing a theoretical guidance for the design of high speed railway system.The main contents of this paper are as follows:(1)Firstly,a dynamic model of high-speed railway system is built.Bearing model is joined into this dynamic model.The bearing model can couple vertical and transverse vibration of high-speed railway system.The dynamics model of system can reflect the reality and close to reality.It also shows the solving method of coupling dynamic equations.(2)A detailed study on contact model of the wheel-rail is carried out.Firstly,it determines the actual position of the wheel-rail contact point to determine the geometric relationship between the wheel-rail contact.Then the method to solve the wheel rail normal contact force and wheel rail creep force is introduced in this paper,Through the contact model of wheel-rail,the vehicle system and track system are linked closely.(3)Typical model of wheel-rail excitation during operation process of train is discussed.This paper clarifies the relevant characteristics of the track irregularity.It carries out the comparative analysis of Chinese and foreign track spectrum.At last,to ensure the accuracy of the system excitation,it introduces the method of numerical simulation of track irregularity power spectrum.(4)An experiment is carried out to test the coupling dynamics model of the bearing.Comparing the response parameters from experimental platform of bearing vibration with the results of the numerical simulation of dynamics,the rationality of coupling dynamics model of bearing is verified.(5)The model of system dynamics is taken into the analysis of engineering example.Considering the contact between wheel and rail,it analyses the dynamic characteristics of the system under the track irregularity.And the incentive and impact on the train dynamics at different speeds and parameters of the system are discussed.