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高速列车在制动过程中,制动盘在制动块的摩擦力作用下温度急剧升高,从而产生了热应力。过高的热应力往往会引起制动盘的疲劳破损,因此在设计制动盘时考虑温度场的影响非常重要。对速度为300km/h的列车在紧急制动工况下的制动盘,建立了含有局部内热源的数学模型和瞬态热传导方程。采用微分求积法,对热传导方程中的温度函数进行关于空间坐标的离散,得到了离散节点上仅含时间自变量的温度函数表示的一阶常微分方程组,然后采用龙格-库塔法求解。最后,对Mechanite Cast Iron G.C.40、AISI301、Chromium Copper Casting三种材料制造的制动盘进行分析和计算,得到了制动过程中温度随时间和沿轮轴半径的变化情况。结果表明:导热好的材料的温度沿径向分布的均匀程度好;制动过程中有动压力作用时,导热好的材料在有效摩擦区域沿径向的温度场与热流的分布规律基本一致,并逐渐趋向于稳态值。
During the braking process of high-speed train, the temperature of the brake disc rises sharply under the friction force of the brake pad, thereby generating thermal stress. Excessive thermal stress tends to cause fatigue damage to the brake disc, so it is important to consider the effect of the temperature field when designing the brake disc. On the brake disc of the train with speed of 300km / h under the emergency braking condition, the mathematical model with local internal heat source and the transient heat conduction equation are established. The differential quadrature method is used to discretize the temperature function in the heat conduction equation with respect to the spatial coordinates. The first-order ordinary differential equations, which are represented by the temperature function with time-dependent variables on the discrete nodes, are obtained, then the Runge- Solve. Finally, the brake discs made of Mechanite Cast Iron G.C.40, AISI301 and Chromium Copper Casting were analyzed and calculated, and the change of temperature with the radius of the axle during braking was obtained. The results show that the temperature distribution of the material with good thermal conductivity is uniform along the radial direction. When dynamic pressure is applied during the braking process, the distribution of the thermal conductivity along the radial direction in the effective friction region is basically the same, And gradually tend to steady-state value.