Abstract

The braking phenomenon is an aspect of vehicle stopping performance where with kinetic energy due to the speed of the vehicle is transformed into thermal energy via the friction between the brake disk and its pads. The heat must then be dissipated into the surrounding structure and the airflow around the brake system. The frictional thermal field during the braking phase between the disk and the brake pads can lead to excessive temperatures. In our work, we presented numerical modeling using ANSYS software adapted in the finite element method, to follow the evolution of the global temperatures for the two types of brake disks, full and ventilated disk during braking scenario. Also, numerical simulation of the transient thermal and the static structural analysis were performed here sequentially, with coupled thermo-structural method. Numerical procedure of calculation relies on important steps such that the computational fluid dynamic (CFD) and thermal analysis have been well illustrated in 3D, showing the effects of heat distribution over the brake disk. This CFD approach helped in the calculation of the values of the heat transfer coefficients (h) that have been exploited in the 3D transient evolution of the brake disk temperatures. Three different brake disk materials were tested and comparative analysis of the results was conducted in order to derive the one with the best thermal behavior. The current numerical results were in good agreement with the previous experimental results available in literature. Finally, the resolution of the coupled thermomechanical model allows us to visualize other important results of this research, such as; the deformations, and the equivalent Von Mises stresses of the disk, as well as the contact pressure distribution on the brake pads. According to the results presented in this investigation, several conclusions can be drawn. The choice allowed us to deliver the excellent rotor design to ensure and guarantee the better braking performance of the vehicles.

摘要

制动现象是车辆停止性能的一个方面，其中由于车辆速度而产生的动能通过制动盘与其刹车片之间的摩擦转化为热能。然后热量必须消散到周围的结构和制动系统周围的气流中。在制动阶段，制动盘和制动片之间的摩擦热场会导致温度过高。在我们的工作中，我们使用适用于有限元方法的 ANSYS 软件进行了数值建模，以跟踪两种制动盘（全盘和通风盘）在制动情况下的全球温度演变。此外，瞬态热和静态结构分析的数值模拟在这里依次进行，采用耦合热结构方法。数值计算过程依赖于重要步骤，因此计算流体动力学 (CFD) 和热分析已在 3D 中得到很好的说明，显示了制动盘上热量分布的影响。这种 CFD 方法有助于计算已在制动盘温度的 3D 瞬态演变中利用的传热系数 (h) 的值。测试了三种不同的制动盘材料，并对结果进行了比较分析，以得出具有最佳热性能的一种。目前的数值结果与文献中先前的实验结果非常一致。最后，耦合热机械模型的分辨率使我们能够可视化这项研究的其他重要结果，例如；变形，和盘的等效 Von Mises 应力，以及刹车片上的接触压力分布。根据本次调查的结果，可以得出几个结论。该选择使我们能够提供出色的转子设计，以确保和保证车辆具有更好的制动性能。