The lifting lug is one of the most important structures of aerial bomb, which mainly bears the variable amplitude cyclic loading during the working process. In this paper, the failure analysis of several lifting lugs which failed in fatigue test was carried out. Firstly, through the mechanical analysis, fatigue cumulative damage analysis and fracture surface analysis of the lifting lug structure, it was determined that the fracture failure was not caused by the issue of structural design, but by the Al₂O₃ inclusion defect in the casting process. Next, the crack source defect was equivalent to the initial crack, and the fatigue full-life was predicted by the method of fatigue crack growth (FCG). The FCG process was divided into two stages: small crack growth stage and long crack growth stage for life prediction respectively. Finally, the validity of this method was verified by comparing with the experimental results, and it was suggested to adopt advanced lifting lug casting and detection technology to prevent similar faults.

吊耳是航空炸弹最重要的结构之一，在工作过程中主要承受可变振幅的循环载荷。本文对几种吊耳的疲劳试验进行了失效分析。首先，通过对吊耳结构的力学分析，疲劳累积损伤分析和断裂面分析，确定断裂失效不是由结构设计问题引起的，而是由Al ₂ O _{3引起的。}铸造过程中的夹杂物缺陷。接下来，裂纹源缺陷与初始裂纹等效，并且通过疲劳裂纹扩展（FCG）方法来预测疲劳全寿命。为了预测寿命，FCG过程分为两个阶段：小裂纹增长阶段和长裂纹增长阶段。最后，通过与实验结果的比较，验证了该方法的有效性，建议采用先进的吊耳铸造和检测技术，以防止类似故障的发生。