摘要
黏着力是列车安全与平稳运行的关键因素之一.最大黏着力与摩擦力有关,摩擦力的减小会导致黏着力的降低.表面粗糙度及其取向是影响摩擦系数的重要因素,然而,有关表面粗糙度取向对于混合润滑状态下摩擦系数的影响的研究结论似乎是矛盾的.用激光离散改性技术将车轮试样表面制备成具有菱形、纵纹、横纹3种典型的形貌,并且与不作激光离散改性处理的车轮试样作对比,用基于确定性模型的统一雷诺方程数值分析法和小比例尺度的轮轨试样摩擦学实验,得到的结论是:在油润滑状态下,激光表面形貌大幅提高摩擦系数,其中菱形对应的摩擦系数最大,纵纹与横纹的摩擦系数相差不大,摩擦系数的大小主要取决于由表面粗糙度取向决定的接触区内粗糙峰接触压力与总压力之比,侧流效应也是影响摩擦系数的重要因素,它主要取决于接触区内表面粗糙度的取向.
Adhesion is one of the key factors to maintain safety and stability of train running. Maximum adhesion is related to the friction. The decline of friction results in decrease of adhesion. In fact the friction coefficient on mixed lubrication is not only greatly influenced by surface roughness, but also by roughness orientations. However, the previous investigations regarding the effect of roughness orientation on friction coefficient seem to be contradictory. In this paper,the three typical surface roughness orientations, i.e., longitudinal, transverse and rhombus were treated by laser discrete modification technology. The behavior of three patterns of roughness orientations under mixed lubrication were compared to those of without laser treatment. A numerical analysis based on deterministic model with unified Reynolds equation was adopted. Tribology tests with scaled wheel/rail specimens were carried out. It is concluded that the wheel surface with laser patterns greatly enhanced the friction coefficient comparing with the surface without laser pattern. The friction coefficient of rhombus pattern is the greatest one among that of the three laser patterns. The friction coefficient of longitudinal and transverse pattern is almost the same, but the former is a little higher than that of the latter. The friction coefficient is mainly depended on the ratio of asperity contact pressure to the total pressure in mixed lubrication. The orientation effect on friction coefficient is also determined by lateral flow which is highly depended on the geometry of contact region.
作者
蔡宝春
蒋华臻
王文中
李正阳
王保安
杨兵
任志远
Cai Baochun Jiang Huazhen Wang Wenzhong Li Zhengyang Wang Baoan Yang Bing Ren Zhiyuan(Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China Mechanical and Vehicular Engineering College, Beijing Institute of Technology, Beijing 100190, China)
出处
《力学学报》
EI
CSCD
北大核心
2016年第5期1114-1125,共12页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家自然科学基金(51275510)
国家重点基础研究发展计划(973)(2011CB711103)资助项目
关键词
弹流润滑
表面形貌
滚动接触
轮/轨
elasto-hydrodynamic lubrication
surface topography
rolling contact
wheels/rails
