钢轨主动打磨磨石界面热应力分析及影响研究

Thermal Stress Analysis and Its Influence at the Grinding Stone-rail Interface

为分析钢轨打磨时的摩擦、磨损及疲劳损伤,根据传热学理论,通过热机耦合方法,运用ABAQUS软件建立钢轨打磨有限元模型,以分析不同车速、打磨电机功率和打磨宽度对钢轨表面温度场和应力场的影响。钢轨与砂轮之间摩擦所产生的热量等效为一个移动热源,数值分析磨削过程中钢轨表面的温度、应力及应变状态。结果表明:钢轨打磨是一个快速升温、缓慢降温的过程;高温区温度场、等效应力场均呈以打磨轴线为中心、向四周扩散的椭圆形分布,且打磨高温区深度较浅,打磨产生的高温影响范围有限;钢轨表面最高温度随打磨车速度和打磨宽度的增加而减小,随打磨电机功率的增加而增加,仿真结果与实际打磨情况较为符合。

To analyze the friction, wear and fatigue damage during rail grinding, finite model is established using ABAQUS based on the heat transfer theory and thermal-mechanical coupling to analyze the influence of speeds, power of grinding machine and grinding width on the temperature field and stress field on the rail surface. The heat generated due to friction between the rail and grinding wheel is like a mobile power source. Data derived from the finite model is used to analyze the rail surface temperature, stress and strain status. The simulation results show that rail grinding may cause rapid temperature rise and slow cooling; both the temperature field and equivalent stress field within the high temperature zone present oval distribution with grinding axis as the center. The high temperature zone has a shallow depth and its influence scope is limited. The highest temperature on the rail surface decreases with increase of the speed of grinding machine and grinding width while increases with increase of power of the grinding machine. The simulation result also proves to be conforming to the field result.