高速列车合金锻钢制动盘温度场仿真分析

Simulation Analysis on the Alloy-forge Steel Brake Disc Temperature Field for a High-speed Train

紧急制动时的制动盘温度状况与其使用寿命密切相关,而如何准确预测制动盘摩擦表面的温度及温度场分布成为研究摩擦制动盘表面磨损、金相转变及热裂纹的关键技术。本文提出了一种把热辐射系数折算成对流换热系数的方法,建立了锻钢制动盘三维循环对称有限元模型、热输入数学模型及对流散热数学模型。用平均轴制动功率法,对高速列车“中华之星”在270 km/h紧急制动时制动盘温度场分布进行仿真。仿真结果表明,高速列车实施紧急制动时,制动盘摩擦升温最高可达935℃,且高温区域集中在制动盘摩擦表面的中部区域。在1∶1制动动力台进行紧急制动试验,试验结果与仿真数据比较接近,从而验证了该模型的有效性,为制动盘应力场分析及其结构参数优化提供了直接依据。

The service life of a brake disc depends on the temperature status during emergency braking. How to forecast the surface temperature and its distribution accurately becomes the key technology to study surface wearing, metallographic transformction and thermal cracking of the brake disc. A new method which translates the heat radiation coefficient into the film coefficient is put forward. The 3-D cyclic symmetric structure model, heat imported model and heat convection disperse model are established. Using the method of the average axle braking power, the temperature distribution of the brake disc of the high-speed train China Star was computed. The numerical simulation result shows the highest temperature will attain to 935℃ in emergency braking and the high temperature zone will concentrate in the middle of the friction area of the brake disc. The test of emergency braking was made on the 1 ： 1 test-bed, and the highest temperature of the brake disc was obtained. The convergence between the simulation results and the test data is sufficient to validate the mathematical model, which will offer a direct basis for the stress analysis and structure parameter optimization.