Abstract: The status of out-of-round high-speed wheels is measured at regular intervals and analyzed in detail. Using the commercial code SIMPACK developed a dynamic model for a high-speed vehicle coupled with a track, which considers an effect of out-of-round wheels on the dynamical behavior of wheel/rail. The model is used to analyze the influences of the status of the out-of-round high-speed wheels on the dynamical behavior of the wheels/rails based on the typical measured data of out-of-round wheels. The analyzed dynamical behavior of the wheels/rails includes the vertical accelerations, the lateral misalignments, the normal forces, the creep-forces and the frictional power of the wheelsets. The mechanism of wheel out-of-roundness development is illustrated by using the characteristics of the creepages and the creep-forces of wheel and rail. The numerical results show that the different out-of-round wheels with similar radial runout have different influences on the wheel/rail behavior. The high-order polygonal wear of the wheels has a great influence on the vertical dynamic performances of the wheels/rails, and the nonuniform working hardening on the wheel circumference, which is caused by the wheel/rail impact at high frequencies, is a main factor to lead to the quick development of the out-of-roundness. The local geometry defects with long wavelengths on a wheel tread often lead to the large impact loads and acceleration and friction power of the wheel. Besides, a larger friction power generates on the circumference with littler radius of a radial runout wheel, which can increase the development of the out-of-roundness.

Key words: Coupling dynamics model of vehicle/track, High-speed train, Measurement, Wheel out-of-roundness, Wheel/rail behavior