摩擦块形状对制动盘摩擦温度及热应力分布的影响

列车制动产生的摩擦热在制动盘表面的分布与闸片结构密切相关,并影响到制动盘的耐热疲劳程度.基于实际应用的圆形、六边形、三角形3种形状摩擦块的制动闸片,利用有限元分析软件ABAQUS,模拟制动时制动盘的温度及热应力分布情况.结果显示:制动盘摩擦表面温度及热应力呈环形带状分布,沿周向变化不明显,在径向上分布的均匀程度差异较大;其变化程度与摩擦块形状和位置有关,摩擦块为圆形时,盘面的温差和热应力最小,摩擦块为三角形时,盘面的温差和热应力最大;摩擦块的位置分布影响到摩擦副接触弧长度,接触弧长度增加,对应的摩擦环带温度升高;各环带对应的接触弧长度偏差越小,制动盘温度越低,分布也越均匀.

Influence of Brake Pad Shape on Friction Temperature and Thermal Stress of Brake Disc

The distribution of friction heat generated during braking action on brake disc surface is closely related to the brake pad and affects the thermal fatigue resistance of the brake disc.By the finite element software ABAQUS,the temperature and thermal stress of the brake discs were calculated,when they practically coupled with three types of brake pads whose cross-sections were round,hexagon and triangle,separately.The results show that the distributions of temperature and thermal stress on brake disc surfaces are displayed in ring band,with no obvious change in circumferential direction but larger difference of uniformity in radial direction.The variations of temperature and thermal stress distributions are related with the shapes and positions of the friction pads.When the friction pad cross-section is round,the temperature difference and thermal stress of the disc are at minimum,and when the friction pad cross-section is triangle,the temperature difference and thermal stress of disk are at maximum.The contact arc length of the friction pair is influenced by the distribution of friction pad position,and the temperature on friction ring rises when the contact arc length of the friction pair increases.The less difference of the contact arc length for the ring bands,the temperature is lower and the temperature distribution more uniform.