通风盘式制动器热抖动现象仿真分析

Hot Judder Simulation for a Ventiled Disc Brake

制动器是汽车制动系统的核心部件,以目前轿车上普遍采用的通风盘式制动器为例,应用非线性有限元软件Abaqus建立制动器摩擦接触的热—机耦合的有限元模型,模拟紧急制动时制动盘由于热力耦合引起的热抖动现象。仿真结果表明制动过程中温度场和应力场是相互耦合的,并且呈周期性波动,频率和制动盘的转动频率是一致的,制动过程中形成的一个时变的移动热载荷和对流换热的共同作用是温度场和应力场波动的主要原因。不均匀分布的热应力引起制动盘产生向盘毂内侧翘曲和厚度变化的热变形,并由此导致接触状态和接触压力发生变化,引起制动时的热抖动。

Brake is the main components of the vehicle brake system.The paper takes a ventilated disc brake which is currently widely used for passenger cars as an example.The thermal-mechanical coupled finite element model for braking system was established using the non-linear finite element software ABAQUS.The hot judder phenomenon appears for transient temperature field and stress field of the disc are simulated during emergency braking.The results show that the stress field is coupled with the temperature field and they are periodically fluctuated,and the frequency of the fluctuation is consistent with the rotational frequency of the disc brake.The coactions of the time-varying moving thermal load and the convection heat transfer play the major role in the fluctuations of temperature and the stress field.The uniform distribution of the thermal stress causes the disc thermal deformation of warping toward the hub and the thickness variation of the disc.And the thermal deformation causes the contact state and contact pressure changes during braking,then the hot judder appear.