Analysis on the formation cause for the high-order wheel polygonization of the high-speed trains based on the finite element method

The formation cause of high-order wheel polygonization of high-speed trains is investigated. A modelling of wheelset/track interaction based on the finite element method (FEM) is set up. The stability of the wheelset-track system (WTS) is studied by using the complex eigenvalue analysis (CEA) based on the modal coupling theory. The dynamic response of the wheelset rolling on the rails is simulated by the transient dynamic analysis (TDA). The results show that the friction-induced vibration (FIV) of the WTS at about 540 Hz, which is composed of the fifth-order bending mode of the wheel axle and the antisymmetric yaw of the wheels, is the principal cause of the 23-order wheel polygon. The frequency of the FIV responsible for the 23-order polygonal wear hardly changes with the vehicle speed and the coefficient of friction (COF) between the wheel and rail, which coincides with the fact that the wheel polygon of high-speed trains in China tends to be frequency-fixed. The order of wheel polygon is inversely proportional to vehicle speed. The higher the wheel-rail COF and the vehicle speed, the faster the wheel polygonization evolves.