Study On The Relationship Between Frame Load And Wheel Rail Force And Dynamic Stress Of Frame

Due to the increasing speed and density of passenger train,the service environment of train and track material is deteriorating day by day.When the train is running,the line under the action of the various deterministic and non deterministic irregularities and dynamic irregularity and so on,will increase the wheel rail action force.In the process of operation,it can be regarded as a dynamic input/output system.When the wheel rail force changes continuously,the load of the frame is changing constantly,and the dynamic stress of the frame is constantly changing.A lot of research at home and abroad show that many accidents are caused by the fatigue damage of the bogie welded frame under complex alternating load,the frame as a key component of high-speed train,the service life of the structure is highly concerned and valued.At present,there is a high level actual measurement of track and rail force,frame load and dynamic stress of the frame,but if we can use the relationship between them to use the load of the frame to predict the wheel rail force,analysis the influence of structure dynamic stress,which will have great economic significance,inconvenience for some test data to avoid the line measure,and through the correlation analysis of the measured data to evaluate the results.This paper study on the relationship between frame load and wheel rail force and dynamic stress of frame,the bogie frame is treated with ANSYS finite element software,and build a rigid flexible coupling dynamics model in SIMPACK,analyze the relationship between vertical and horizontal respectively.The work and conclusions are as follows:(1)In the vertical direction,the correlation coefficient between the wheel rail force and the load of frame at different speeds is less than 0.3,which is a weak correlation;with the increase of velocity,the high frequency components of the wheel rail force significantly,and the load of the frame due to the damping effect of a vehicle suspension system,the impact is limited;the main vibration frequency of the frame load,which is the same as the suspension vibration frequency;when the vehicle is running as 300km/h at different wavelength as the excitation,which can be founded the frequency in more than 4Hz,the load of the frame and the wheel rail force has obvious phase difference,therefore we can not ignore the different frequency components of phase difference effect on the correlation coefficient of the transfer;and there was a significant correlation between the change of wheel rail force and the load of the frame in different speed RMS and amplitude.According to the vibration frequency of the frame defines the scope,analysis the correlation between the wheel rail force and the load of the frame in low,medium and high frequency region respectively,finally come to a suspension of the natural vibration frequency of the frequency and different speed when the load of the frame frequency distribution is selected according to the frequency interval,the effective value ratio as fitting transfer coefficient can complete the load of the frame and the wheel rail force time history,and to evaluate the fitting curve.(2)Using ANSYS to analyze the maximum stress point of the bogie frame of the vertical force,and also utilizing the transient analysis to analyze the changes of dynamic stress.Because of the frequency component of the frame load is lower than the first order natural frequency of the frame,the effective value ratio of the bogie frame stress and the load of the frame which can be used as the transfer coefficient to analyze the influence of dynamic stress.(3)According to the lateral force in time domain and frequency domain characteristics,extract the related information,put forward the method to use the lateral load of the frame to fit the wheel rail lateral force,and analyze the influence of the dynamic stress of the frame under the action of lateral force.