表面粗糙度对轮轨黏着特性影响

Effect of surface roughness on adhesion characteristic of wheel/rail

水油介质下极易发生轮轨低黏着现象,结合轮轨黏着试验和根据二维滚动接触理论和部分弹流润滑理论建立轮轨黏着数值仿真模型,给出了水油介质下轮轨表面粗糙度对轮轨黏着系数和增黏的影响规律,验证了数值仿真模型的有效性.结果表明:水介质下随蠕滑率增加黏着系数呈先快速增加后小幅减小并稳定的变化;水、油介质下随表面粗糙度增加轮轨黏着系数呈增加趋势;水介质下轮轨表面粗糙度从1μm提高到50μm,黏着系数增加126.5%,油介质下轮轨表面粗糙度从5μm提高到20μm,黏着系数增加61.4%.

Water and oil mediums easily lead to low adhesion phenomena of wheel/rail. This study uses the wheel/rail adhesion experiment, two-dimensional rolling contact theory and par- tial elastohydrodynamic lubrication theory to establish the simulation model of wheel/rail adhe- sion values, and concludes the influence of surface roughness on adhesion coefficient and in- crease adhesion. Besides, this paper verifies the validity of numerical simulation model. The results show that： with the increase of the creep ratio, the adhesion coefficient of wheel/rail firstly increases quickly, and then slightly decreases, finally stays at stable stage under the condition of water medium; As the surface roughness increases, the adhesion coefficient of wheel/rail shows an increasing tendency under the condition of water and oil mediums; under the condition of water medium, the surface roughness of wheel/rail increases from 1 μm to 50 tim, and the adhesion coefficient of wheel/rail increases by 126.5% ; under condition of oil me- dium, the surface roughness increases from 5 μm to 20 μm, and the adhesion coefficient of wheel/rail increases by 61.4%.