【摘要】 利用W-M分形函数，建立考虑钢轨表面粗糙的二维轮轨弹性接触模型，进而引入温度对材料参数和摩擦系数的影响，采用直接耦合法模拟车轮以1m/s速度沿钢轨滑动45mm，阐明粗糙表面的轮轨滑动接触热响应的特性。利用Hertz理论验证了有限元接触算法的精确性，在此基础上研究了表面廓形影响下的接触应力随分形函数自变量维数D和尺度系数G变化的规律，验证了有限元模型模拟粗糙表面的可靠性。研究结果表明：粗糙表面对轮轨温度场分布特点没有影响，但会引起轮轨表面温度和温升过程的波动；车轮最高温度相差4℃，钢轨最高温度相差10℃，且车轮最高温度更高；车轮和钢轨表面的温度波动受D和G的控制，但影响规律存在差异：钢轨表面温度随D和G的改变线性变化，而车轮表面温度变化未体现类似的线性关系。因此，可借助轮轨表面粗糙度特征对钢轨温度波动进行合理预测。更多还原

【Abstract】 The W-M fractal function is used to establish a two-dimensional wheel-rail elastic contact model considering the roughness of the rail surface, the influence of temperature on the material parameters and the friction coefficient is introduced in the model. The direct coupling method is utilized to simulate the wheel sliding 45 mm along the rail at a speed of 1 m/s, and the characteristics of the thermal response of the wheel-rail sliding contact with rough surface are illustrated. The accuracy of the finite element contact algorithm is calculated by Hertz theory. On this basis, the variation of contact stress with fractal function independent variable dimension D and scale coefficient G under the influence of surface profile are studied, and the reliability of the finite element model to simulate rough surface is verified. The results show that the rough surface does not affect the distribution characteristics of the wheel-rail temperature field, but it will cause the fluctuation of the wheel-rail surface temperature and temperature rise process. The maximum surface temperature difference of the wheel pre and post of the test is 4 °C, while that of the rail is 10 °C. Furthermore, the maximum surface temperature of the wheel is higher larger than that of the rail. The temperature fluctuation of the wheel and rail surface is controlled by D and G, but the influence law is different: the rail surface temperature changes linearly with the change of D and G, while the wheel surface temperature does not reflect a similar linear relationship. Therefore, the rail temperature fluctuation can be reasonably predicted with the help of the wheel-rail surface roughness characteristics.更多还原