Objective On fast metro lines with speeds of 120 km/h and above, wheel wear develops quite rapidly, and intense wheel-rail interactions occur when trains pass through turnouts, necessitating an investigation into the influence laws of wheel wear depth on the dynamic performance of trains passing through turnout.

Method Taking a fast metro line in Chengdu (with a maximum operating speed of 140 km/h) as the case study, and focusing on the damage characteristics of the 12# alloy steel combination turnout on the line, wheel profile measurements are conducted on six trains with different operating mileages (corresponding to different wheel wears). Based on measured wheel and turnout data, a vehicle-turnout coupled dynamics model is established using SIMPACK. The wheel-rail relationship and the dynamic response during the train reverse crossing turnout under different wear depths are analyzed, revealing the influence laws of wheel wear depth on the dynamics performance during crossing turnout.

Result & Conclusion As the train operating mileage increases, wheel tread wear gradually deepens, showing a positive correlation between wear depth and mileage, and the wheel wear is primarily located within ±30 mm of the nominal rolling circle. With the increased wheel wear depth, the equivalent conicity of wheel tread also rises, worsening the wheel-rail relationship and intensifying wheel-rail impact during crossing turnout, greatly affecting the running safety of the train. At an operating mileage of 217 000 train-km, the wheel wear depth is approximately 2.22 mm compared to the new wheel condition. Dynamics indicators such as lateral and vertical wheel-rail force, derailment coefficient, wheel lift-off, and bogie frame lateral acceleration show relatively significant increases, all exhibiting a positive correlation with the wheel wear depth. To ensure the safety of metro trains crossing turnout and reduce wheel-rail interaction forces, it is recommended to perform wheel reprofiling when the wear depth reaches 2 mm or after approximately 200 000 train-km of operation.