某型机主减接头断裂失效分析

Failure Analysis of XX Type Helicopter MGB Fitting

某型机主减接头疲劳试验过程中发生断裂。采用断口的宏观和微观分析、能谱分析、金相分析等方法,对主减接头断口进行失效分析。结果表明:主减接头为疲劳断裂,源区侧面的磨损缺陷是引起失效的主要原因;疲劳裂纹萌生于钢衬套安装孔内表面,靠近倒角的位置。最后提出了预防和改进措施,经验证满足设计要求。

The MGB fitting fractured during the fatigue testing. The failure cause was analyzed by EDS analysis, metallographic examination, macro and micro observation on fracture surface. The results show that ： the fracture mode of MGB fitting was fatigue fracture, abrasion was the failure cause of MGB fitting; the crack of MGB fitting sprouted from the assemblage hole surface of bush, close to the corner.