Abstract: Aimed at the wheel polygonization problem of the subway vehicle, discussed the forming reason of the wheel polygonization, put forward the innovation point that the wheel polygonization is caused by the wheel/rail vibration during many wheel rolling circles, and derived the relation between the phase angle of the vertex, main vibration frequency and the running speed of the polygonization wheel. Take one kind of linear induction motor subway vehicle for example, based on the multi-body system dynamic model, the main frequency of the wheel/rail vertical force under different speed is researched, the speed and main frequency which easily induced the wheel polygonization with 9 vertexes is analyzed, and pointed out that the wheel polygonization with 9 vertexes of the subway vehicle maybe formed during the speed scope from 72 km/h to 80 km/h. Take the case of 72 km/h and 80 km/h for example, the results of the wheel/rail vertical force and the main frequency is given in the paper, as well as the LIM of the front bogie. Simulation results show that the wheel polygonization with 9 vertexes maybe formed by the vibration with the frequency of 39.08 Hz and 43.48 Hz. The phase angle changes between the different speeds are present and the sketch map of the wheel polygonization with 9 vertexes is given, too.

Key words: Dynamic, Frequency, Polygonization, Subway, Wheel