某机载雷达天线端轴断裂原因分析与结构改进

End Shaft Fracture Reason Analysis and Structure Improvement for an Airborne Radar Antenna

某机载雷达天线在耐久振动试验中,调心轴承处的端轴出现了断裂现象。文中利用宏观断口观察、化学成分检验及金相组织检验等手段,对断裂的端轴进行了全面分析,并通过有限元仿真得到了断裂端轴的应力分布。结果表明,断裂端轴的化学成分及晶体结构符合规范要求,断裂端轴的最大应力水平大于材料的疲劳极限是断裂的主要原因。针对端轴的断裂原因,对端轴的结构进行了改进,最后通过有限元仿真和耐久振动试验验证了端轴结构改进的有效性。

The end shaft of self-aligning bearing appears fracture phenomenon in the durable vibration test of an airborne radar antenna. In this paper the scientific analysis of the end shaft fractured in the test is done using different measures such as macro-fracture analysis,chemical composition test and metallography structure test. The stress distribution of the fractured end shaft is obtained by finite element simulation. The result shows that the chemical composition and crystal structure of the fractured end shaft meet standard requirements and the maximum stress of the fractured end shaft being greater than material fatigue limit is the main fracture reason. According to the fracture reason,the structure of the end shaft is improved. Finally,the effectiveness of the structure improvement is verified through finite element simulation and durable vibration test.