多次紧急制动工况下的鼓式制动器热-结构耦合分析

Thermal-Structure Coupling Analysis of Drum Break under Multiple Emergency Braking Conditions

针对汽车鼓式制动器在制动过程中的开裂失效问题,基于运动学、动力学、摩擦学与热-结构耦合的综合分析技术及实验技术,建立了三维瞬态热-结构耦合理论模型及有限元模型;分析多次紧急制动工况下制动鼓温度场和应力场在径向、周向、轴向的分布特征,得到了结构场与温度场的耦合作用结果 ;分析了温度、应力应变、压力三者间的相互耦合作用规律.结果表明:制动鼓的开裂失效主要处于温升大的区域,是由热应力引起的热疲劳失效,且由于周向压应力比径向和轴向压应力大,从而导致制动鼓的裂纹方向均为沿轴向伸展.

In view of the automotive drum brakes in cracking failure in the process of braking, based on the kinematics and dynamics of tribological and thermal structure coupling comprehensive analysis technology and experimental technology, the three-dimensional transient thermal coupling theory model and the finite element model are established, the temperature field and stress field in the radial, circumferential and axial distribution characteristics under the multiple emergency braking condition are analyzed. The coupling analysis of structure field and temperature field are obtained, the mutual coupling effect among pressure, stress and strain, temperature is analyzed. The research results show that the brake drum cracking failure is mainly in temperature large area, thermal fatigue failure caused by thermal stress, and due to the axial compressive stress is larger than the radial and axial compressive stress, which result in the crack of brake drum along the axial direction.