车轮表面宏观形貌取向对高速轮轨水润滑黏着系数的影响  

INFLUENCE OF MACROSCOPIC TOPOGRAPHY ORIENTATIONS OF WHEELS ON ADHESION COEFFICIENT OF HIGH SPEED WHEEL/RAIL UNDER WATER LUBRICATION

作　　者：蒋华臻 王保安 李正阳[2] 蔡宝春[2] 杨兵[2] 任志远[2] Jiang Huazhen;Wang Baoan;Li Zhengyang;Cai Baochun;Yang Bing;Ren Zhiyuan(School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049,China;Key Lab of Mechanics in Advanced Manufacturing,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]中国科学院大学工程科学学院,北京100049 [2]中国科学院力学研究所先进制造工艺力学重点实验室,北京100190

出　　处：《力学学报》2018年第1期157-166,共10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计划)(2011CB711103)资助项目

摘　　要：轮胎和沥青都属于低弹性模量材料,即使运动速度较低,流体动压导致的水膜也足以产生润滑作用.对于列车轮轨这类高弹性模量材料,只有当运行速度达到200 km/h以上,水的润滑作用才体现出来,使轮轨黏着系数大幅降低,给高速列车运行带来重大安全隐患.增大表面粗糙度一般能够提高轮轨黏着系数,然而研究表明,在表面粗糙度基本相同的条件下,表面形貌取向对混合润滑状态下的黏着系数有显著影响.文中用统一雷诺方程模型,计算了在水润滑状态下,具有纵纹、横纹、菱形等特定形貌取向的车轮在高速运动时(最高500 km/h)对黏着系数的影响,并将计算结果与平均流量模型计算的结果和已有的实验结果进行了比较.结果表明:各种形貌下,轮轨黏着系数都随速度的增大而减小,其中菱形的黏着系数大于横纹的,而横纹的黏着系数又大于纵纹的,影响黏着系数的主要因素是固体接触压力与总压力之比.在轮轨点接触椭圆率k<1时,接触区的侧流效应不可忽略,用平均流量模型计算会导致谬误.Though tyre and asphalt are low elastic modulus materials,water lubrication resulting from hydrodynamic action would present even the speed is low.For high elastic modulus of materials,such as wheel and rail,water lubrication would present when the speed is over 200 km/h,causing potential unsafety for train operations.Increasing surface roughness will improve the wheel/rail adhesion coecient.However it is shown that the topography orientation also has great e ect on adhesion coecient when the value of surface roughness is nearly the same under mixed lubrication.In this paper,a numerical analysis based on unified Reynolds equation was adopted.The behavior of three patterns of roughness orientations on wheels,i.e.longitudinal,transverse and rhombus,with high speed up to 500km/h under mixed lubrication were analyzed.The simulation results were compared with the results of the average flow model and the existing experimental results.It is concluded that the adhesion coecients of wheel/rail decreased with speed increasing,while the adhesion coecient of rhombus pattern is greater than that of the transverse,and transverse pattern is greater than that of the longitudinal.The adhesion coecient is mainly depended on the ratio of asperity contact pressure to the total pressure.When the ellipticity k<1 in wheel/rail point contact,the lateral flow e ect could not be neglected,the results of average flow model will result in error.

关 键 词：弹流润滑 表面形貌 黏着系数 轮/轨 

分 类 号：TB125[理学—工程力学]