瞬时滑动状态下轮轨摩擦系数试验研究

为研究瞬时滑动状态下荷载、速度对轮轨摩擦系数的影响规律,基于摩擦学第二定律,以U71 Mn钢轨为试验材料,研究瞬时滑动状态下,荷载、速度对轮轨摩擦系数的影响。结果表明:在瞬时滑动状态下,速度对摩擦系数的影响较为显著,摩擦系数随速度的增加而减小,当瞬时滑动速度达到2.6 m/s时,摩擦系数为0.34,较初始测定速度降低10%。摩擦力与荷载的增加成正比,但在瞬时滑动速度恒定的条件下,摩擦系数几乎不受荷载改变的影响。车轮发生瞬时滑动时,较大列车轴重和较小车轮自旋速度有利于车轮获得较大摩擦力,这对行车安全是有利的。列车瞬时滑动状态与制动状态下的摩擦系数是有差异的,在工程实际和轮轨接触分析时应根据车轮的滑动状态选用相应的摩擦系数。

Experimental Research on Wheel/Rail Friction Coefficient under Transient Sliding Condition

To study the transient sliding condition,the influence of load and speed on the wheel/rail friction coefficient,U71 Mn rail is used as the experimental material to analyze the influence of load and speed on the wheel/rail friction coefficient under transient sliding condition based on the second law of friction. The results show that the effect of velocity on the friction coefficient is significant,and the friction coefficient decreases with the increase of the velocity. When the transient sliding speed reaches 2. 6 m/s,the friction coefficient is 0. 34,which is 10% lower than the initial measurement speed. The friction is proportional to the increase of load,but the friction coefficient does not change with the load at constant transient sliding speed. When the wheel instantaneously slips,the larger train axle load and smaller wheel spin speed help the wheel to obtain a greater friction,which is beneficial totraffic safety. The friction coefficient under rain instantaneous sliding state is different from that under braking state,thus,corresponding friction coefficient should be selected according to wheel sliding state in engineering and wheel-rail contact analysis.