FRICTION MATERIAL DOWNSCALING AND ITS EFFECT ON BRAKE SYSTEM PERFORMANCE

Coefficient of friction is considered to be a system property. Unlike physical properties of a material, coefficient of friction is dependent on an entire system. Surface roughness, wear rate, temperature and velocity are some of the factors that influence the COF in a brake system. Due to these factors, current testing strategies fail to make an accurate prediction about the performance of a brake system in smaller scale. This paper explores how a small-scale tester correlates to a full scale dynamometer test when proper scaling strategies are utilized. Series of tests are carried out on non-asbestos organic, semi metallic and low steel using the Bruker’s Universal Mechanical Tester (UMT) TriboLab. Results are then compared to the Greening full-scale dual ended brake dynamometer (Horiba) using AK master standard procedure. Area based Scaling laws are applied as the approach to scale down the conditions of the full- scale dyno test for UMT test. As friction is a system property, dynamometer and UMT tests showed different results. However, performance (COF) for these tests between UMT and Dyno has the same general trend. Therefore, with more repetition on different friction material, it is possible to make more relevant and accurate predictions of performance