40t轴重货车制动热负荷分析

增加轴重是重载运输提高运能的重要途径之一,然而轴重的增加对制动系统提出了更加严格的要求。采用数值方法,对40t轴重货车紧急制动和长大下坡道制动的车轮热负荷情况进行了模拟,对其温度场和热应力场进行了分析,基于制动热负荷对轴重40t货车车轮的强度进行了预测。结果表明紧急制动和长大下坡道制动最高温度均出现在车轮踏面处,其幅值分别为233℃和231℃;最大热应力分别出现在踏面和辐板外侧靠近轮毂处,其幅值分别为348MPa和252MPa。不同温度下的von Mises应力计算结果表明最大应力值均未超出材料的屈服极限。

Thermal Load Analysis of Wheels for 40tAxle-load Freight Car under Braking Conditions

The increase of axle-load is one of the important ways for heavy-haul freight car to improve its transport capacity.However,the demand on the braking system is much higher.With a numerical method,the thermal load of the emergency braking and the grade braking of 40tAxle-load freight car are imitated,and the temperature field and thermal stress are analyzed.The strength of the wheel based on thermal load is predicted.The result shows that the maximum temperature of the emergency braking and the grade braking both occur on the tread of the wheel.The maximum value is 233℃and 231℃respectively.The maximum thermal stress of the emergency braking occurs on the tread of the wheel,however the maximum thermal stress of the grade braking occurs on the wheel plate near wheel hub.The maximum value is 348MPa and 252MPa respectively.Compared with the yield limit of the material,it is found that the von Mises stresses on different temperatures are not beyond it.