An experimental investigation on the tribological behavior of brake pads for high-speed trains in sandy environments

Addressing the tribological issues of train braking in sandy railway areas, an experimental study was conducted utilizing a self-developed high-speed train brake dynamometer. Three different sand particle size ranges served as mediums to investigate the friction and wear characteristics of brake pads, thermal distribution at the interface, and interfacial vibration and noise characteristics in sandy environments. The study focused on the evolution and disparities in interfacial tribological behavior and explored the relationship between the surface wear of brake pads and other interfacial behaviors. The results indicate that introducing all three types of sand particles increases the interfacial friction coefficient and disrupts the original wear debris layer on the brake pad surface. However, significant differences were observed in the surface wear behavior under different sand particle sizes. The incorporation of very fine sand (VFS) led to the formation of three distinct wear characteristic regions on the brake pad surface, gradually increasing interfacial temperature difference. In contrast, the interfacial temperature difference gradually became more uniform under fine sand (FS) and medium sand (MS) conditions. Furthermore, a diminishing trend in the tendency for interface-induced vibration and noise was noted under VFS and FS conditions, while its intensity progressively increased under MS conditions.