Investigation on Thermo-Mechanical Coupling Characteristics of Disc Brake System of High-Speed Train

To study the effect of thermo-mechanical coupling on the dynamic behavior of high-speed train disc braking system, a three dimensional transient thermo-mechanical coupling finite element model of high-speed train braking system was established, and thermo-mechanical coupling characteristics were calculated and analyzed. The ABAQUS/Explicit heat-displacement transient analysis method was used to discuss the temperature distribution characteristics and vibration behavior during brake process. Additionally, the system dynamic behavior was compared with the situation when ignores the thermo-mechanical coupling state. The results show that the temperature distribution of brake pad is in the process of dynamic change, and local high temperature zone will be formed on the pad surface and accordingly lead to hot spots. Due to the elastic heat deformation of disc and pad in a certain extent, the temperature distribution characteristics of brake pad in circular and radial directions are complicated. In the process of braking, the oscillations of brake pad in both the normal and tangential directions gradually become weaken, but the overall deformation tends to increase gradually, and the deformed displacement can reach 6 μm. Thermal deformation mainly occurs on two sides of the pad, the amount of deformation in the entering friction area (35 μm) is visibly larger than that in the out friction area (25 μm), and the center of the pad presents an obvious “sunken” phenomenon, which indicates that there is no significant thermal deformation generated in the center of the pad. The vibration of the braking system increases firstly and then decreases and the vibration level is stronger than that in the case of ignoring the thermomechanical coupling of brake system. The fluctuation level of interface contact force firstly increases and then decreases, but it possesses a visible increase trend.