Research On The Wheel-rail Force Indirect Measuring Method Of Urban Rail Transit

In recent years,China’s urban rail transit has been developed rapidly,a dense transportation line network has been formed in many cities in China.Among them,the safe operation has always been the top priority of the urban rail transit industry.When evaluating the safety of the vehicle,the wheel-rail force is needed.Due to the disadvantage of wheel-rail force direct measuring method on the law of high installation costs,high operation difficulties,complicated wheelset calibration and incidental damage to the wheels,it is necessary to study the indirect measuring method.In this thesis,the safety problems of urban rail transit vehicles in operation were mainly studied.From the perspective of vehicle dynamics,combined with the indirect measuring method of basic theory analysis,vehicle dynamic model numerical simulation analysis,and direct measuring method and indirect measuring method were analyzed in comparative experiments.The rail vertical force and the lateral force of the wheel axle are obtained by indirect measuring method,and the safety indicators such as the derailment coefficient and the wheel load reduction rate are calculated.Finally make the wheel-rail force indirect measuring method has been made on-site applicability while meeting the accuracy requirements.The specific research work is as follows:(1)Research has been conducted on the theory of wheel-rail force indirect measuring method.The principle of wheel-rail force indirect measuring method in urban rail transit were analyzed,and the theoretical calculation formula of the lateral force of the wheel axle and the rail vertical force were derived.A corresponding calculation program was developed using the MATLAB toolbox.By inputting data such as vehicle parameters and measured vehicle responses into the program,the lateral force of the wheel axle and the rail vertical force can be identified.(2)Research has been conducted on the feasibility of wheel-rail force indirect measuring method.Through the vehicle dynamics simulation software SIMPACK,the urban rail transit vehicle simulation model was established,and the responses of urban rail transit vehicles under different speeds and lines are analyzed.The simulation results were compared with the wheel rail force results obtained by the indirect measuring method calculation program,and the feasibility of the indirect measuring method was verified.(3)Research has been conducted on the application of wheel-rail force indirect measuring method.Install the direct measuring method and indirect measuring method testing equipment on the urban rail transit test vehicle.Firstly,based on the joint safety domain of the wheel-rail force indirect measuring method and traditional derailment evaluation indicators,the safety evaluation analysis of vehicle operation was conducted to verify that the calculation program of the indirect measuring method can accurately evaluate the safe operation of vehicles.Then compare and analyze the error between the wheel-rail force test results of the direct measuring method and the indirect measuring method under the same working condition,so that the calculation program of the wheel-rail force indirect measuring method has on-site applicability while meeting the accuracy requirements.