Experimental study on the temperature evolution in the railway brake disc

Abstract

Increasing operating speed of modern passenger railway vehicles leads to higher thermal load on the braking system. Organic composite brake pads are poor thermal conductors, hence frictional heat is absorbed mainly by the disc. In this study three brake pad types were tested on the dynamometer. Metallic fibres, steel and copper, were introduced to the formulation of two materials. The third was a non-metallic material – a reference case. Dynamometer test comprised emergency brake applications to determine the frictional characteristics of the materials and constant-power drag braking to analyse the effect of metal fibres on temperature evolution, measured by six thermocouples embedded in the brake disc. Mean friction coefficient is analysed and discussed. It is concluded that conductive fibre in the friction material formulation may influence its tribological characteristics. Despite high thermal conductivity, metal fibres in the concentration tested in this study, did not reduce temperature of the brake disc. Keywords: Railway disc brake, Heat partition, Thermal conductivity, Full-scale dynamometer test