Thermal and tribological study of a periodic contact under braking conditions

The present work concerns the tribological and thermal studies of periodic contact obtained during successions of railway stop-brakings. Tests with heat accumulation, performed on a braking tribometer, permit the observation of a modification of the friction coefficient, a wear increase and the presence of a large compacted third body layer on the pad surface. An analytic model of thermal conduction is developed for the determination of the disc surface temperature evolution during the succession of stop-brakings. The results obtained using mass temperature measurements during the succession are compared with those estimated by pyrometry; a good agreement is found.