Effect of wheelset eccentricity on the out-of-round wheel of high-speed trains

Wheelset geometric eccentricity and mass eccentricity are generally considered to be the main reasons behind the formation of the 1st order out-of-round (OOR) wear (or eccentric wear) of railway wheels. Based on finite element simulation, the relationship between wheelset geometric eccentricity and the high-order OOR wheels of high-speed trains was studied in this paper. Moreover, the reason for the phase difference between the polygonization on the left and right wheels of a railway wheelset was discussed. The results show that, when the train runs at a high speed of 237 km/h, a wheelset's geometric eccentric value greater than 0.7 mm can lead to longitudinal creep forces on the left and right wheels to periodically reach saturation during operation, causing frictional self-excited vibrations of about 605 Hz in the wheel-rail systems; and resulting in 24th - 25th order wheel polygonal wear. The phase difference between the geometric eccentric directions of the left and right wheels can cause the phase difference between the saturation states of the creep forces on these wheels, resulting in the phase difference between the 1st and 24th - 25th order OOR shapes on these wheels. In addition, during the assembly of the trailer wheelset, when the phase difference between the residual static unbalance values of the wheel and brake disc is 180 degrees, the unbalanced force couple caused by the wheelset mass eccentricity is minimal, which then slows down the formation of 1st order OOR shapes on the trailer wheels.