A study on an analysis model for the thermo-mechanical behavior of a solid disc brake for rapid transit railway vehicles

One of the primary interests in the railway field is to improve speed as well as to secure the safety of railway vehicles at a high speed. In light of this, the demand for braking systems that offer improved performance and safety has also been growing consistently. The braking system is a critical element directly connected with safety. In order to secure reliability and establish the maintenance standard for the braking system, it is necessary to secure an accurate evaluation technology. As the braking disc of the braking system is very sensitive to safety and maintenance, a method to evaluate thermal cracking must be developed. Because the brake disc goes through a repeated process of heating and cooling due to the friction energy and the heat convection, respectively, in every braking action, it is subject to thermal fatigue. As well, the partial contact area caused by friction between disc and pad during the braking process results in thermal distortion, causing a hot band and a hot spot. This thermal distortion may also cause thermal cracking on the friction surface. The aim of this research was to find the cause of thermal cracking through a thermo-mechanical friction analysis of disc and pad, and to verify the analysis model through the dynamo machine.