Friction-induced vibration and noise characteristics, and interface tribological behavior during high-speed train braking: The effect of the residual height of the brake pad friction block

Abstract

A tribology test was carried out on a test device to simulate the braking performance of a high-speed train and investigate the effect of the friction block's residual height on friction-induced vibration and noise (FIVN) characteristics and interface tribology behavior. A finite element model (FEM) of the test device was established using the real boundary conditions and component material parameters. A wear simulation of the friction block was performed, and the Archard wear equation was used to obtain the surface wear of the friction block after stable friction had occurred. Complex eigenvalue analysis (CEA) and implicit dynamic analysis (IDA) were carried out. The effect of the friction block's height on the surface wear level, the complex mode and dynamic response, and the interface contact behavior are discussed. The results show that the friction block wears at an angle due to the friction force at the braking interface. Thus, the contact stress occurs predominantly at the leading edge of the friction block, leading to significant wear, high temperatures, and eccentric wear of the friction block. The taller the friction block, the larger the inclination angle is, and the more significant the eccentric wear degree is. Excessive wear at the leading edge causes debris to enter the brake interface. As a result, the wear surface of friction block is significantly damaged, including large contact plateaus and extensive exfoliation and ploughing. This damage increases the complexity of the braking interface's tribological behavior and causes high-intensity FIVN. However, the inclination angle decreases as the friction block's height decreases, resulting in better wear behavior of the friction interface and lower FIVN intensity. Although the friction block height significantly affects the intensity and evolution of FIVN, it does not change the system's inherent frequency.