Frictional Characteristic Evaluation of Composite Brake Block Using a Reduced-Scale Brake Dynamometer

Abstract

Brake blocks are important components that function to decelerate the speed of train. The safety of railway transportation depends on the reliability of this component. One of the important characteristics of the brake block material is the friction coefficient. The brake block material should have the required friction coefficient. The friction coefficient of material is measured by friction test. Previous research showed that the braking conditions including contact pressure and sliding speed affect the friction coefficient of a material. Many friction methods have been developed to study the characteristics of friction material. In contrast to previous studies, in this study, frictional characteristic of composite brake block with resin phenolic matrix was evaluated using a reduced-scale brake dynamometer. By pressing the brake block specimen against the wheel tread friction test was conducted. The size of the brake block specimen and the train wheel were reduced to ¼ original size. Friction measurements were carried out at contact pressure of 0.10, 0.15, 0.20, and 0.25 (MPa) and sliding speed of 3, 6, 9, and 12 (m/s). The results showed that the friction coefficient of the composite brake block decreased with increasing sliding speed, but increased with increasing contact pressure. The friction coefficient of composite brake blocks addressed values that was vary from 0.296 to 0.404. Meanwhile, wheel temperature increased with increasing sliding speed and contact pressure.