Page 31 - 摩擦学学报2025年第8期

第 8 期 刘雄强, 等: 多次制动工况下列车制动闸片摩擦块磨损行为的演变规律分析 1129

reaches its wear limit. The wear of the friction block not only affects the tribological behavior at the brake interface but
can also, in severe cases, threaten the safety of the train’s braking. Therefore, studying the wear behavior of the friction
block during its service is of significant importance. Different service environments, braking parameters, material
compositions, and friction block structures make the wear behavior of the friction block extremely complex. Scholars
have primarily studied it through experiments and simulations. However, existing research is generally limited to
analyzing the damage to the friction block, the distribution of contact pressure and the evolution of wear under single
braking conditions. Yet, in the actual service process, the friction block has to undergo multiple braking conditions
repeatedly. Current research seldom analyzes the impact of multiple braking conditions on the wear behavior of the
friction block. To clarify the wear behavior of friction block under multiple braking conditions, single and multiple
braking tests were conducted using a scaled braking test bench. Furthermore, a thermo-mechanical coupled wear
analysis was performed using finite element models to explore the evolution of contact pressure and wear during the
braking process. The results indicated that after multiple braking conditions, the size of spalls on the friction block
surface increased, the number of spalls decreased, and edge spalling was more pronounced. The number and size of
matrix cracks near the friction interface had increased; the average crack length was 51 μm after a single braking and
increased to 149.2 μm after multiple braking conditions. During the running-in process, severe wear was observed at the
cutting-in end of the friction block, and significant wear in the middle of the friction block was noted during the first
braking, with a maximum wear depth of 56.1 μm and a minimum wear depth of 37.8 μm, showing a difference of
18.3 μm. In subsequent braking processes, the wear of the friction block became more uniform, with the difference
between the maximum and minimum wear depths within 1 μm, and the overall wear depth continually increased with the
number of brakings. The distribution of contact pressure of the friction block and the evolution of the main wear areas
were influenced by the initial wear state, thermal expansion behavior and wear behavior. The research results revealed
the evolution law of the wear behavior of the friction block under multiple braking conditions, which could provide
necessary theoretical support for the design optimization of the friction block.
Key words: multiple brakings; friction block; wear behavior; pressure evolution; railway train

空气制动系统是列车运行安全的重要保障之一， 磨损行为的影响，发现接触压力分布与宏观接触形态
其通过制动盘与制动闸片摩擦块间的摩擦作用，将列 密切相关，压力的不均匀分布会导致损伤形态的多样
[1]
车动能转换为热能从而实现制动 . 列车在服役过程 性，从而恶化磨损状态，进而增加摩擦系统的不稳定
[17]
中频繁的停车、降速和调速等，会导致制动闸片摩擦 性. Chen等 采用仿真方法研究了热膨胀和制动参数
块不断磨损，直至磨耗到限 [2-3] . 摩擦块磨损不仅影响 的共同竞争作用对摩擦块磨损的影响，并通过制动试
制动界面的摩擦学行为 [4-6] ，甚至会威胁列车的制动安 验验证了仿真结果的准确性. 研究发现，摩擦块的动
全. 因此，研究列车服役过程中摩擦块的磨损行为具 态磨损分布受到热膨胀和摩擦副相对运动的共同影
有重要意义 [7-9] . 响，热膨胀引起凹面磨损，相对运动引起偏心磨损. 制
[11]
[12]
[10]
不同的服役环境 、制动参数 、材料成分 和 动压力和速度的增加分别加剧了摩擦块的偏心磨损
[13]
摩擦块结构 等条件，使得摩擦块的磨损行为极其复 和凹面磨损.
杂，学者们主要通过试验和仿真这2种手段对其进行 以上研究中对摩擦块磨损行为的揭示具有重要
[14]
研究. 卢纯等 研究了摩擦块在跑合阶段的摩擦学行 意义，但不难发现，现有研究中一般局限于对单次制
为，发现在跑合初期，摩擦块上的接触压力不均匀导 动工况下摩擦块的损伤情况、接触压力分布及磨损演
致切入端迅速磨损，宏观接触面积增加. 随着跑合过 变进行分析. 然而，在摩擦块的实际服役过程中要重

程的进行，平均接触应力逐渐保持稳定. 范志勇等 [15] 复经历多次制动，目前的研究中鲜有分析多次制动工
选取CRH380A型高速动车组制动闸片作为研究对象， 况对摩擦块磨损行为的影响.
利用多种微观分析手段对该闸片摩擦粒子的损伤特 为此，本文中利用缩比制动试验台，针对同一制
征进行了分析，发现摩擦粒子的主要损伤特征为剥 动工况分别进行了单次和多次制动试验，利用光学显
落和裂纹. 应力集中和材料加工过程中形成的气穴和 微镜、白光干涉仪和扫描电子显微镜(SEM)等微观特
不同组元之间结合强度不足等原因导致了裂纹的萌 征分析仪器，对比研究了单次制动工况与多次制动工
[16]
生与扩展. Qian等 研究了不均匀磨损对摩擦块摩擦 况下摩擦块磨损行为的区别. 同时，建立了热机耦合