加油吊舱转接件裂纹失效分析

Cracking Analysis of Refueling Pod Adapter

飞机地面试验时发现加油吊舱转接件出现裂纹并漏油,该加油吊舱转接件为焊接组合件,裂纹出现在盖板的近R角处,盖板铸件材料为ZL116铝合金。通过采用外观观察、断口分析、金相组织分析、成分分析、力学性能测试等方法,对加油吊舱转接件裂纹产生原因进行分析,并进行人工断口的对比分析。结果表明:加油吊舱转接件开裂是由大应力和组织塑性差共同作用所致,大应力主要来源于结构应力集中、焊接内应力、焊接后校形应力、装配及试验应力等;提出铸件改为预拉伸板或增加焊道距R角的距离等改进措施。

The refueling pod adaptor of an aircraft was found to have crack and leak during testing. The refueling pod adaptor was welding assembly. The crack was found near R angle of the cover plate, whose material is ZL116 alumium alloy. The failure mode and cause were analyzed by macro and micro observation, microstructure examination, chemical composition analysis, and mechanical property testing. The results show that the crack of the adapter was caused by the co-effect of the poor plasticity and excessive stress. The excessive stress mainly came from the structure stress concentration, welding stress, shape correction stress, assembly and test stress. It is suggested that the cover plate should be replaced with a pre-stretching plate or the distance between R angle and the welding path should be increased.