Continuous Measurement Of Wheel-rail Vertical Force And Identification Of Wheel Flat

With the train speed and axle load increasing,wheel-rail relationship becomes more intense and complex.Railway transport security situation becomes more severe.so the accurate measurement of wheel-rail force is particularly important.In the method of wheelrail force measurement,the ground test wheel-rail force is one of the more accurate and lowcost methods.This way through the composition of the bridge and paste the strain gauge,and connect the test system to record and analyze the state of wheel and rail contact force to determine whether there are security risks.During the running of the train,the wheel-rail contact change is very complicated.Changes in the contact caused the train wheel and rail different degrees of defects.The defects of the train wheel and rail will affect the stability,safety,comfort and service life of each part of the track.In this paper,the following research work is carried out on the basis of the continuous measurement of wheel / rail vertical force and the recognition of wheel flat.1.The finite element model of wheel-rail is established by ABAQUS finite element software.the simulation results of wheel-rail force are considered without considering the flatness of the wheel and the track irregularity.In the analysis of the model,considering the different speed,the influence of the defect on the rail state is analyzed by extracting the vertical displacement and vibration acceleration of the rail and the spring deformation.The results show that the influence of different speed on the vertical displacement of the rail is very small,and the acceleration of the rail vibration increases with the increase of the vehicle speed.At the same time,the influence of the train speed on the deformation of the spring is not obvious,that is to say,there is little influence on the buckling pressure of the rail fastener.2.In this paper,the method of continuous testing of wheel-rail force is proposed,and the finite element model is established for simulation analysis.Comparing with the scale test data,it is proved that the theory and simulation model are correct.The method is applied to the actual subway line,and the actual wheel-rail force strain signal is obtained.In order to eliminate the Gauss white noise in the acquisition signal,the experimental simulation signal and measured wheel rail force strain signal are processed by wavelet packet and EMD correlation algorithm.It is proved that this method can effectively improve the signal noise reduction and improve the accuracy of signal analysis and highlight the characteristics of the signal.3.The wheel flat model is used to analyze the characteristics of wheel-rail impact on different wheel flat lengths.The results show that the wheel-rail impact force increases with the increase of the length of the wheel flat.The method of EEMD decomposition is used to analyze the wheel rail impact force caused by wheel flat,and then to identify the wheel flat.