Interactions between Third-Body Flows and Localisation Phenomena during Railway High-Energy Stop Braking

During railway braking, dissipation of high energy due to friction leads to transient and localised thermal phenomena such as hot bands and hot spots. These localisation phenomena interact with third body flows and friction mechanisms activated in the contact. To study these couplings, an experimental approach has been developed, based on an inertial tribometer able to reproduce high thermo-mechanical brake-disc loadings. This paper focuses on the coupling between flows of third-body and hot-band migration. Transient localised thermal phenomena are described for high-energy stop-braking. The monitoring of the disc track during friction in the visible and infrared wavelengths evidences the interactions between third-body flows and hot-band migration. The consequences relatively to load-bearing areas and third-body compaction in the contact are studied, allowing the proposal of a synthetic diagram of the coupling between friction mechanisms, third body flows, hot-band migration and first-body distortion.Cross Reference: