软油箱连接管开裂与鼓泡分析

Analysis of Cracking and Bubbling for Connecting Tubes

一架飞机在地面试车时发生起火,检查发现是软油箱连接管漏油所致。本文采用视频显微镜对软油箱连接管宏观失效特征进行检查,采用扫描电子显微镜对开裂处断口进行微观形貌观察,结合硬度测试,对软油箱连接管开裂原因进行分析。结果表明,软油箱连接管的开裂为疲劳开裂,开裂的主要原因是连接管无夹布、紧固钢丝和胶层之间粘结不良,使得连接管的疲劳抗力下降所致。连接管内外表面的鼓泡也是由于胶层层间粘结不良使得燃油在间隙处积累所致。

Leakage of fuel because of cracking of the tank connecting tubes led to fire of the airplane during trial run. Appearantes of the connecting tubes of tank were observed by 3D video microscope. The fracture surface of the cracks on the tubes was analyzed by Scanning Electron Microscope and the hardness of the tubes was inspected. The results show that the cracks on the tubes are fatigue cracks, which caused by the reduction of fatigue resistance due to absence of fabric and fasten steel wire and poor agglutination of rubber layers in the tube. As well the bubbling on the tubes is formed through the accumulation of the oil in the gap between the rubber layers due to the poor agglutination of the rubber layers.