Effect of Wheel Polygonization on Vehicle-Track Coupling System with Different Track Structures

Wheel polygonal wear aggravates the dynamic responses of vehicle-track coupling systems, especially for the wheel-rail interaction force and rail vibration acceleration, which will influence train operation safety. Previous studies about wheel polygonal wear mostly focused on high-speed trains, while freight trains and track systems are rarely involved. This paper presents a comprehensive investigation of the wheel polygonization effect on the dynamic responses of vehicle-track coupling systems, involving a high-speed train, a heavy haul freight train, ballasted tracks, and slab ballastless tracks. With the combined excitation of track irregularity and wheel polygons of different orders and wave depths, the simulation results are analyzed in the time domain and frequency domain, and this indicates that the rail accelerations and wheel/rail forces of slab tracks induced by over-15th order polygonal wear are more intense than those of ballasted tracks as high-speed trains pass at speeds of 300 km/h and above, and the responses of freight trains are more severe than those of passenger trains on ballasted tracks. For the vehicle system of freight wagons, wheel polygonization has a more obvious effect on the wheelset than the car-body and bogie frame. Moreover, rail vertical acceleration is more sensitive to the various types of wheel polygonal defect in different track structures, and this can serve as a vital indicator of polygonal wear.