铆钉疲劳断裂原因分析及疲劳应力估算  

Fatigue Fracture Cause Analysis and Fatigue Stress Calculation of Rivet

作　　者：陈星[1,2,3] 卢增威 胡成江[5] 

机构地区：[1]北京航空材料研究院中航工业失效分析中心,北京100095 [2]航空材料检测与评价北京市重点实验室,北京100095 [3]材料检测与评价航空科技重点实验室,北京100095 [4]中航工业沈阳飞机工业(集团)有限公司,沈阳110850 [5]中航工业成都飞机工业(集团)有限责任公司,成都610091

出　　处：《失效分析与预防》2016年第4期246-249,共4页Failure Analysis and Prevention

摘　　要：飞机服役90 h后检查发现15a框与进气道蒙皮连接处第一个铆钉头发生断裂。通过外观观察、断口宏微观观察分析,金相、硬度、以及断口定量反推疲劳应力方法,结果表明铆钉为疲劳断裂。铆钉连接的框和蒙皮之间安装孔同轴度存在偏差,导致异常的转配弯曲应力与正常的工作时承受剪切应力不符,再叠加气流振动应力,使得铆钉的起始应力较大,是铆钉断裂的原因。通过断口定量分析还给出了铆钉为疲劳综合起始应力较大、扩展应力较小。The first rivet between the frame and the aircraft skin was found to have fractured after serving for 90 h. In the present work,macro and micro observation,microstructure examination,hardness testing,and quantitative analysis on fracture surface were carried out. The results show that the failure mode of the rivet is fatigue fracture. The poor axiality of the mounting holes of the frame and the skin resulted in abnormal assembly bending stress. The abnormal assembly bending stress combined with the vibration stress by air current led to greater initiation stress,which is the main cause for the fracture of the rivet. Last,based on quantitative analysis of fracture,it is found that the initiation stress of the rivet is greater and the propagation stress is smaller.

关 键 词：铆钉 疲劳断裂 断口定量分析 应力反推 异常装配 

分 类 号：TH131.1[机械工程—机械制造及自动化]