Research On Tracking Measurement Method Of In-Service Wheel And Axle Of EMU

As bogies contribute greater effect to the EMU’s operation, it is necessary to take deeper research on wheels and axles tracking and testing method on EMU bogie to guarantee safe operation. This paper, setting CRH6A powered and non-powered wheels as studying objects and referring technical guidance of Lucchini RS spa, did feasibility analysis on instrumented wheelset. The author finally makes the verification and fatigue strength assessment on the measure scheme by simulation calculation and practical measurement. The main contents and conclusions are summarized as the followings:(1) Developing instrumented wheelset bridging form solution, planning wheel-rail force solving method and analyzing harmonic on wheel and axle bridging form, this research result showed:axle bridge waveform is close to cosine wave, and its combined output is close to a constant value; the wheel bridge output is triangular wave little fluctuation.(2) Author took simulation calibration test on instrumented wheelset, and then statistical analyzed the results. The results showed:wheel and axle bridge outputs were corresponded with harmonic analysis result.(3) Based on simulation result and other working conditions, the writer made research on wheel-rail force solving method by least square method. The results showed: the calibration matrix solved by the wheel bridge was the most accurate; otherwise the calibration matrix solved by the axle bridge was least accurate. Overall consideration, the author decided to test vertical force by axle bridge and test horizontal force by wheel bridge. In addition, there is solving accuracy on bending moment method.(4) Based on practical testing data and spectral analysis on axle signal, author did time-domain analysis on wheel-rail force solved by calibration matrix and bending moment method in typical working conditions. Then author researched the different speed effects on load spectrum feature in line and curve working conditions. The results showed:the wheel-rail force solved by the two methods corresponds with the practical working situation; the calibration matrix method solved horizontal force better.(5) Based on strength simulation and practical measurement on wheels and axles, the writer made the assessment on the axle strength of instrumented wheelset. The simulation results showed:wheel meets the requirements of static strength and fatigue strength. The test data showed:non-powered axle meets the requirement of 12 million kilometers operation.