摘要
螺栓是汽车、桥梁等钢结构中广泛使用的紧固件。重要螺栓的断裂常常导致灾难性事故。本文通过几起BJ/XJ213汽车转向机固定螺栓的断裂分析,指出了事故发生的客观原因及存在于人们思想中的主观原因。测定了螺栓预紧扭矩与产生预紧应力之间的对应关系,同时用扫描电镜观察了典型的螺栓断口特征。结果表明,螺栓联接部位的加工缺陷及不合理的装配,使得固定螺栓在服役过程中承受了异常的交变弯曲载荷,导致了最终的疲劳断裂。
Threaded fasteners are widely used in steel structures such as automobiles, bridges, etc. The failure of key bolts ofuen results in vital incidents. Based on the failure analysis of Steering Gear Case bolts of BJ/XT 213 jeeps, the spujective and objective reasons for the failure were found. From desigened tests, the relation between preload torque and the corresponding clamping axial stress on a bolt was established. Fracture surfaces of failed bolts were examined using a scanning electron microscope. It came to the conclusion that the welding misfit of the Spacer-Steering Gear Case with the shell as well as the unreasonable assembly made the bolts bear an abnormal alternaring bending load during the service and caused fatigue failure finally.
出处
《机械工程材料》
CAS
CSCD
1992年第1期53-58,共6页
Materials For Mechanical Engineering
