汽车减振器连杆磨损失效和断裂力学分析

Wear Failure and Fracture Mechanics Analysis of Automobile Absorber Connecting Rod

采用扫描电子显微镜观察连杆磨损表面形貌 ,并结合断裂力学方法研究了减振器连杆的磨损机理 .研究结果表明 :导向器衬套中的玻璃纤维在服役过程中崩出 ,作为磨粒存在于连杆和衬套摩擦副接触表面之间 ,可压碎铬镀层使裂纹扩展 ,并且断裂的铬镀层也可成为磨粒 ;连杆铬镀层存在裂纹缺陷加剧其磨损 .连杆磨损机理是以断裂机制为主导的磨粒磨损机制 ,裂纹扩展是磨损的控制因素 ,并且以 型断裂为主导 ;摩擦力是裂纹扩展的主要驱动力 .

The wear mechanism of the automobile absorber connecting rods was investigated by means of fracture mechanics and scanning electron microscopy. The results show that the glass fibers in the guiding bush are pulled out and existed between the contacting surface of the connecting rod and the guiding bush during the operation of the connecting rod. The detached glass fibers can act as abrasive particles to cause the abrasive wear by way of crushing the chromium-plating layer on the rod surface and accelerating the propagation of cracks. The crush chromium-plating layer can then also act as abrasive particles to enhance the abrasive wear of the connecting rod, which is also accelerated by the crack defects in the chromium-plating layer. The wear mechanism is characterized by abrasive wear, which is dependent on the crack propagation near the interface of the chromium-plating layer and the rod matrix. The fracture mechanism is characterized by mode I fracture, while the friction force is the dominant driving force for the propagation of cracks.