| Wheel-rail relationship is the most important and basic relationship in railway system.Wheel-rail load is the basis of wheel-rail relationship,which has a very important impact on the dynamic performance and structural reliability of high-speed EMU/rail system.It is also of great significance to the study of wheel-rail load distribution and its law,especially the statistical distribution law of high-speed EMU.In this thesis,the wheel-rail loads of high-speed EMUs are taken as the research object.Relying on the wheel-rail loads obtained from the continuous measurement of force-measuring Wheelsets on the West Line test,the stress-load transfer coefficient is obtained by processing the calibration test data,and the time history of the measured wheel-rail load is obtained by filtering,deburring and envelope processing.Combined with the rigid-flexible coupling dynamic simulation method,the wheel-rail load characteristics of high-speed EMUs are studied.(1)From the time domain analysis,it can be concluded that the wheel-rail vertical force is affected by the vehicle load state.When running in a straight line,the wheel-rail vertical force mainly fluctuates around the static wheel weight and wheel-rail lateral force fluctuates around 0 kN,mainly under small load.When the curve passes,the wheel-rail vertical force occurs eccentric load,and the wheel-rail lateral force on both sides increases.The main frequency of wheel-rail vertical force is distributed in the range of 10-100Hz.The main frequencies of wheel-rail vertical force is distributed in the range of 10-50 Hz;In the straight line condition,the correlation between vertical force and transverse force is weak;In the curve condition,the effective value and amplitude of the vertical and lateral force of the outer wheel-rail are highly correlated.(2)Statistical results of all data points of wheel-rail load show that the vertical force of wheel-rail is normal distribution,and the lateral force of wheel-rail has two peaks.Because of different statistical data,the distribution shape of peak-valley value of wheel-rail load is different,but it shows the same law.(3)The train running speed,load status and line condition will have certain influence on the wheel-rail force.The specific performance is as follows:the higher the train running speed,the larger the distribution range of the wheel-rail vertical force.At the same speed,the maximum value and amplitude of the wheel-rail force of the heavy-duty working conditions are greater than the empty working conditions.When entering the curved section from a straight line,if the running speed of the train is greater than the equilibrium speed,the vertical force of the outer wheel will increase,the vertical force of the inner wheel will decrease.Additionally,the lateral force will also increase,but the degree of increase of the outer wheel is large.When the running speed is lower than the balancing speed,the vertical force of the inner wheel increases,the vertical force of the outer wheel decreases,and the lateral force of the inner wheel increases.(4)In order to obtain the wheel-rail load data of more lines,a rigid-flexible coupling dynamic model was established.The Wu-Guang line excitation is used to study the wheel-rail load characteristics.The fluctuation range of wheel-rail vertical force and transverse force obtained by simulation based on rigid-flexible coupling model of train is smaller than the measured results.The vertical force of wheel-rail and the measured vertical force load of track have the same characteristics in time domain and are normal distribution;unlike the measured transverse force of wheel-rail,the simulated transverse force of wheel-rail is normal distribution.The vertical force of wheel and rail fluctuates around the static wheel weight and the lateral force of wheel and rail fluctuates around 0 kN when the train is in the straight line section.In the curve section,the vertical force of wheel and rail appears unbalanced load,and the fluctuation center and range of the lateral force of wheel and rail all tend to increase.56 pictures,25 tables,69 references. |
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