Calculation of the temperature field in the thermal sensitive disc-pad couple during multiple braking

Abstract

An analytical model of frictional heating in a railway disc brake system during a multiple braking process is proposed. It considers the thermal sensitivity of the friction coefficient and the thermophysical properties of the materials. The developed model accounts for convective cooling of the brake disc only during the intervals between consecutive braking applications. The theoretical outcomes were compared with experimental data obtained from simulation on a full-scale inertia dynamometer for a friction node consisting of a cast iron railway brake disc combined with a composite friction material. An increase in temperature (by 30–50 °C) at each subsequent braking, accompanied by a simultaneous decrease in the friction coefficient, was observed. The analysis indicated that the relative difference between the maximum temperature values at each braking stage, derived from the model and the data recorded by the thermocouple system during testing, was less than 5 %. The good agreement of the theoretical results with the experimental data confirms the validity of the proposed model, which can be used to estimate the temperature of a disc brake operating in multiple braking modes with non-uniform cycles. Previously, such schemes have only been developed and validated for single and repetitive short-term braking modes.