车轮扁疤对轮轨冲击的影响分析

为探究列车车轮旧扁疤对轮轨冲击的影响规律,建立了考虑柔性轮对的高速动车刚柔耦合模型和有限元扁疤损伤接触模型。分析了不同位置分布的单或双扁疤对轮轨冲击的影响,以避免车辆运行状态下发生跳轨冲击,保证运营安全,并为高速动车组安全运行时车轮损伤限值确定提供依据。分析结果表明:旧单扁疤产生的轮轨垂向冲击力随车速的增大先增大后减小,在100 km/h处达到峰值;速度为100~200 km/h时,当双扁疤间隔70°以下时,第一旧扁疤对第二旧扁疤有增益作用,当间隔70°以上时,增益明显减少,可视作独立扁疤;当车轮存在长度为30 mm的双扁疤时,车轮发生跳轨后最大冲击应力可以达到1059 MPa。

Analysis on the Influence of Flat Spot on Wheel rail Impact

In order to explore the influence law of train wheel old flat spot on wheel rail impact, a rigid flexible coupling model of high speed train considering flexible wheelsets and the finite element contact model of flat spot injury were established. The influence of single or double flat spot on wheel rail impact in different position distribution was analyzed to avoid the rail jump impact under the running state, in order to guarante the operation safety and provide basis for determining the limit of wheel damage during the safe operation of high speed EMU. The analysis results show that the wheel rail vertical impact force generated by the old single flat spot first increases then decreases with the increase of the vehicle speed, and reaches the peak value at 100 km/h; if the speed is between 100~200 km/h, when the interval between the double flat spot is below 70°, the first old flat spot has a gain effect on the second old flat spot,when the interval is above 70°, the gain decreases significantly and both flat spot can be regarded as the independent flat spot; when there is a double flat spot with a length of 30 mm on the wheel, the maximum impact stress can reach 1 059 MPa after rail jump.