覆冰条件下轮轨黏着特性研究

Research of Wheel-Rail Adhesion Characteristics under Rail Icing Caused by Low-Temperature Precipitation

摘要: 在开放环境中服役的轮轨系统接触界面有时会受到冻雨、冰等污染，极大地影响轮轨间的黏着水平，造成列车车轮制动滑行和牵引空转，严重影响列车的运营安全。针对这一问题，利用首创的绕行式轮轨黏着特性模拟试验台及其配套的高低温箱，进行了模拟冻雨天气下覆冰时，不同速度、轴重、喷水量和轨面温度下的轮轨黏着特性测试试验，进而研究覆冰条件下轮轨黏着特性。试验结果表明：在模拟冻雨形成的覆冰条件下，速度、轴重、喷水量和温度会影响黏着系数。同时，速度与喷水量影响着覆冰厚度，覆冰厚度到达一定阈值(1 μm左右)也会显著影响黏着系数，在速度较低，喷水量较大时，黏着系数会降低至0.05左右。

Abstract: In open operating environments, the wheel-rail contact interface of railway systems can occasionally be contaminated by freezing rain and ice, which greatly reduces the adhesion level between the wheel and rail, leading to braking wheel slide and traction wheel slip and thus seriously compromising operational safety. To address this problem, a series of adhesion tests were conducted under simulated icing conditions induced by freezing rain using a newly developed bypass-type wheel-rail adhesion characteristic simulation test rig and a supporting high/low-temperature chamber. Tests were performed at different speeds, axle loads, spray-water flow rates, and rail-surface temperatures to investigate wheel-rail adhesion characteristics under ice-covered conditions. The results indicate that, under ice formed by simulated freezing rain, speed, axle load, spray-water flow rate, and temperature all affect the adhesion coefficient. In addition, speed and spray-water flow rate influence the ice thickness; when the ice thickness reaches a threshold (approximately 1 μm), it also significantly affects the adhesion coefficient. At relatively low speed and high spray-water flow rate, the adhesion coefficient can decrease to around 0.05.