盘式制动器热—结构耦合的数值建模与分析

Numerical Modeling and Analysis of the Thermal-structure Coupling of the Disc Brake

在充分考虑移动热源且速度可变效应影响、盘与片摩擦界面间热流耦合的基础上,根据制动盘与摩擦片的实际几何尺寸,建立一个紧急制动工况下三维瞬态热-结构耦合的计算模型,运用大型有限元软件ANSYS中的非线性有限元多物理场方法,数值模拟盘式制动器的制动过程。揭示制动过程中制动盘瞬态温度场/应力场的分布规律,发现二者之间存在着耦合关系,二者随制动时间明显地呈现周期性变化,这些周期波动是由移动热源产生的热流冲击和对流换热影响的交替作用所引起的,且其变化周期随制动时间的延长而增大。并初步探讨制动盘产生径向裂纹的原因。

According to the real dimension of the braking disc and the pads, the modeling for three-dimensional transient thermal-structure coupling during the emergency braking is established based on the effect of the moving heat source with relative sliding variation and the coupling of the frictional thermal flow between the disc and the pad. By using the nonlinear multiphysics field of the ANSYS software, the braking process of the disc brake is simulated. The distribution of the temperature and the stress of the disc during the braking are analyzed. The temperature and the stress are coupled. During the braking, the transient temperature/stress variation present periodical fluctuations due to the entering heat flux and the thermal convection alternately. The variational period of the temperature/stress increases with the braking time prolonged. And the reason of radial thermal fatigue fracture of the disc is discussed.