高速列车制动闸片摩擦块形状对制动界面摩擦学行为的影响

在自行研制的高速列车制动缩比试验台上，对六边形、五边形和圆形摩擦块进行拖曳制动试验，研究摩擦块形状对高速列车制动界面摩擦学行为的影响，并采用有限元方法分析了不同摩擦块形状下制动界面接触行为的差异，探讨了摩擦块形状对接触压力分布及表面热分布的影响. 结果表明:摩擦块形状显著影响了制动界面磨损特性及接触压力分布，使得制动盘产生不同的温度分布现象. 在本试验条件下，六边形摩擦块表面磨损轻微，接触平台大小较为均匀，而五边形和圆形摩擦块表面呈现明显的犁沟和剥落特征，且大接触平台占比较高；六边形摩擦块与制动盘拖曳制动过程，界面具有较大的接触面积，使得接触压力分布较为均匀，表现出较好的接触行为，而五边形和圆形摩擦块的接触行为相对较为复杂，与之对摩的制动盘产生明显的热聚集现象. 

Effect of Brake Pad Friction Block Shape on Tribological Behavior of Brake Interface of High-Speed Train

The dragging brake experiments using hexagon, pentagon and circular friction blocks were conducted on a self-developed high-speed train braking shrinkage ratio dynamometer, to investigate the influence of friction block shapes on the tribological behavior of brake interface of high-speed train. The finite element method was performed to analyze the difference of the brake interface contact behavior under different friction block shapes, and the influences of the friction block shapes on the contact pressure distribution and surface heat distribution were discussed. The results showed that the friction block shape can significantly affect the wear characteristics and contact pressure distribution of the brake interface, resulting in different temperature distribution of the disc. In this study, the surface of the hexagonal friction block was slightly worn and the size of the contact platform was relatively uniform, while the pentagonal and circular friction blocks showed visible ploughing and exfoliation, and the large contact platform accounted for a relatively high proportion. For the hexagonal friction block, a larger contact area was formed during the drag braking process between the block and the disc, which made the contact pressure more uniform and showed better contact behavior. By contrast, the contact behaviors of the cases of pentagonal friction block and the circular friction block were relatively more complex, which resulted in visible temperature concentration on the disc.