On the modelling of the friction characteristics of railway vehicle brakes

Abstract

The rules and standards that define the requirements and methods for the layout of friction brake systems for railway vehicles still demand extensive experimental surveys since the general confidence in the theoretical predictability of the brake pad friction behaviour is limited. In fact, a review of numerous measurements from dynamometer test rigs exposes a large variation of the friction characteristics. Nevertheless, these measurements could be exploited to develop an elaborate friction modelling approach that includes deterministic and stochastic influences. The comparison of vehicle measurements from field tests with simulation results reveals that a significant improvement of the theoretical predictability of braking distances is within reach. Consequently, this applies as well for a more virtual layout and acceptance procedure for railway vehicle brake systems in the future.