高速列车盘形制动系统热机耦合特性分析

为了研究热机耦合对高速列车制动系统动力学行为的影响，建立了高速列车制动系统三维瞬态热机耦合有限元模型，进行拖曳制动状态下热机耦合特性的计算与分析；采用ABAQUS/Explicit热-位移瞬态分析法，探讨列车制动过程中的温度分布特性和振动行为，并与忽略热机耦合状态的系统动力学行为进行对比分析. 研究结果表明:制动过程中闸片温度动态变化，且会形成局部高温区导致热斑形成；由于制动盘和闸片发生一定程度弹性翘曲变形，导致闸片温度周向分布和径向分布出现复杂的温度分布特性，在闸片的内外径处和进/出摩擦区域的温度分布差异显著；制动过程中闸片在法向和切向上的振荡程度逐渐减弱，但是总体变形量逐渐增大，位移形变量达到6 μm；热变形主要发生在闸片两侧，闸片在进摩擦区的变形量（35 μm）明显大于出摩擦区处（25 μm），而闸片的中部出现明显的"凹陷"，即随着制动进行，闸片中部区域没有出现明显的热变形；在热机耦合状态下，制动系统振动先增大后降低，整体振动强度比忽略热机耦合时强；界面接触力的波动程度先增大后降低，总体呈上升趋势. 

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.