Chapter 10 - Brake testing

Abstract

This Chapter describes and explains the role and methods of experimental testing in the design and verification of brakes and their components. It starts by discussing the increasing capability of computer-based predictive techniques, which can simulate many aspects of brake operation and save time and cost compared with previous methods of experimental evaluation. Preparation, procedures, instrumentation, data acquisition and results analysis, interpretation, and reporting for experimental testing ranging from whole vehicle braking performance on a test track to component performance, particulate emissions, and material thermophysical properties in the laboratory, are explained and discussed. The design and operation of test rigs including inertia dynamometers for full-size brakes, scale rigs for small-sample friction and wear measurement, and machines for cyclic loading, and material property measurement are described. The importance of careful preparation of the friction pair (bedding-in and burnishing) for brake performance testing and the evaluation of variability by repeat testing is emphasised. Considerations relating to inaccuracy in experimental techniques, such as temperature measurement, including the characteristics of thermocouples and the effect of surface emissivity on IR temperature, are discussed.