Influences of friction self-excited vibration characteristics of various types of high-speed trains on rail corrugations in braking sections

To study the typical rail corrugation in braking sections at large slope downhills of Chinese highspeed railways, finite element models of wheelset-rail-brake systems of various high-speed trains are established in the present paper. Then, the complex eigenvalue analysis method is used to study friction self-excited vibration characteristics of wheelset-rail-brake systems in braking sections at large slope downhills. Finally, the influences of friction coefficient of the braking subsystem and vertical fastener stiffness of the wheelset-rail subsystem are analyzed. Results show that the friction self-excited vibration of the entire system induced by the stick-slip friction coupling effect of the wheelset-rail subsystem and the rolling-slip friction coupling effect of the braking subsystem is the dominant cause of rail corrugation. Then, the brake combination of the wheel disc and axle disc is more likely to cause the friction self-excited vibration of the wheelsetrail-brake system than the single braking mode. Parametric analyses show that with the increase of the friction coefficient of the braking subsystem, the self-excited vibration of the entire system increases, which means that the possibility of rail corrugation increases. Furthermore, with the increase of the vertical fastener stiffness of the wheelset-rail subsystem, the self-exicted vibration of the entire system first decreases and then gradually increases. When the vertical fastener stiffness is 30 MN/m, rail corrugations can be suppressed to a certain extent.