Thermographic Monitoring of Temperature Evolution in Railway Brake Disc

초록

In mechanical brake system, the hot spots on the surface of brake disc have been considered as thermal distortions with high thermal gradient, and the control of hot spots has been an important issue for the lifetime extension of brake disc. The brake disc shows sudden temperature increases due to high speed sliding friction between disc and pad. When the disc undergoes repeated friction with pads, hot spots can be formed on disc surface, and hair cracks and/or thermal deformation on disc surface could be generated. Since the initial hot spot control is of important to ensure premature failure of brake disc, the analysis of hot spot mechanism is needed. In this investigation, the temperature monitoring on the surface of the railway brake disc was performed using infrared (IR) thermography technique. The infrared camera employed for this investigation has max speed of 380 Hz, and the braking tests with the railway brake disc were performed with a full scale dynamometer. During the braking test, the high-speed infrared camera was used to monitor surface temperature changes on the brake disc. Therefore, the main objectives of this investigation are to understand the hot spot phenomenon on the railway brake disc, monitor the temperature evolution on the disc surface during braking using the IR thermography technique, and finally, investigate comparison study on the temperature evolution measurements during brake operation between thermocouples and thermographic method in railway brake disc, which is currently employed for Korean railway operation. In summary, A high-speed infrared (IR) camera was used to measure the surface temperature of brake disc as well as for in-situ monitoring of hot spot evolution during braking operation.