Research On The Scheme Of Wheel Rail Force Instrumented Wheelset Bridge Scheme In Urban Rail Transit

In recent years,urban rail transit in China has been developed rapidly,anddense transportation networks have been formed in many cities in China.The issue of operational safety has always been a key focus in urban rail transit operations.Accurately obtaining wheel rail forces is an important foundation and prerequisite for evaluating the operational safety of urban rail transit vehicles.The force measuring wheel set technology is currently the most accurate way to measure wheel rail force,so it is of great significance to use force measuring wheel set technology to more accurately measure wheel rail force.Based on this issue,in this article,a threedimensional finite element model was established to simulate the bridge assembly calculation of the force measuring wheel set;And through the calibration test bench of the force measuring wheel set,a large number of experimental tests were completed,and a new type of force measuring wheel set bridge combination scheme was proposed.Finally,the effectiveness of the new force measuring wheelset bridge combination scheme was verified.The main research content and conclusions of this article include:1.Research has been conducted on the knowledge related to force measuring wheel sets.The research status of wheel rail force detection methods both domestically and internationally was Summarized;The composition and continuous measurement principle of wheel rail force was introduced;The measurement principle of wheatstone bridge and conducted strain calculation for single bridge harmonics was elaborated;The measurement scheme of the force measuring wheel set in the national standard GB/T5599-2019 is introduced.2.A simulation analysis was conducted on the force measuring wheelset bridge scheme,and parameters such as the number of patches,bridge radius,and patch angle of the force measuring wheelset bridge scheme were selected for calculation.The force measuring wheelset bridge scheme at the simulation level was obtained.A threedimensional finite element model of the vehicle wheelset was established using ANSYS software,the strain distribution of the wheelset spoke plate under static load is obtained through simulation calculation.The response of the pickup point to a single direction force is used as the selection index for the bridge radius,and the optimal bridge radius is obtained.Through the gradient descent method,based on the periodic strain time curve obtained from simulation analysis,the bridge combination scheme is calculated in the national standard GB/T5599-2019 and the multiple working conditions of a single bridge containing 4～8 sets of axisymmetric strain gauge using PYTHON software.With the average error as the selection index of the bridge combination scheme,the dynamometer wheel set bridge combination scheme at the simulation level was proposed.3.An experimental study was conducted on the scheme of force measuring wheelset bridge assembly,and a force measuring wheelset bridge assembly scheme based on measured data was obtained.The force measuring wheel set test system was introduced,the static load tests on the strain response of 1/4 bridge single piece,and rotational tests on the strain response of 1/4 bridge single piece were completed.Similarly,the optimal bridge radius is determined by the strain distribution of the spoke plate;Using the gradient descent method,based on the periodic strain time curve obtained from the test,the test data were analyzed and processed using PYTHON software,and the multiple working conditions of a single bridge containing 4 to 8 sets of axisymmetric strain gauge were calculated.Taking the average error as the selection index of the bridge combination scheme,the bridge combination scheme of the dynamometer wheel set based on the measured data was proposed.By comprehend sively comparing and analyzing the calculation results of simulation and actual measurement,the final determination of the force measuring wheel set bridge scheme was made.4.A straight spoke plate force measuring wheel set calibration test was conducted to verify the bridge assembly scheme of the force measuring wheel set.A calibration plan for the force measuring wheel set was developed,and the calibration coefficient matrix was solved through analysis and calculation of the data collected from the calibration experiment.A rotation test was conducted on the strain response of the straight spoke plate full bridge,and the measured wheel rail force curve was calculated using the calibration coefficient matrix.The accuracy of the force measuring wheelset was tested,and the measured curve of the wheel rail force was compared with the actual curve,verifying the effectiveness and accuracy of the straight spoke plate force measuring wheelset bridge combination scheme was studied in this thesis.