Research on service behaviour of brake pad fastener snap ring during high-speed train braking process

Disc brake performance is an important guarantee for the safe operation of high-speed trains. Brake pad fastener snap rings may fail during train braking, causing the friction body to fall off, which is a serious threat to the safety of train operation. This article establishes a finite element model of brake pads/discs taking into account the thermal-mechanical coupling field in the braking process. The temperature distribution of the brake disc surface, the displacement and stress results of the snap rings at different positions are investigated. The results show that the temperature of the brake disc rises and then falls during braking, and the surface temperature of the brake disc is spread in the form of an annular band. The highest displacement and stress variations are found in the snap ring group around the speed entrance area and the inner side of the brake pad. In the x and z directions, the average displacement changes are 0.1967 and 0.1233 mm, respectively. The average changes in contact stress and internal stress are 9.8 and 15.5 MPa. The results of the service behaviour of the snap ring provide a basis for the study of snap ring failure.