摘要
飞机锁闭机构的连接螺栓在修理过程中发生断裂,利用体视显微镜、扫描电子显微镜、金相显微镜、能谱仪等,对断裂螺栓断口及螺牙的宏微观形貌、微区成分、金相组织、显微硬度等进行分析,并与未断裂螺栓进行对比,探究其断裂原因。结果表明螺栓断裂原因为过载。由于工艺文件中未明确力矩要求,为研究拧紧过程中螺栓应力分布情况,确认合理的拧紧力矩数值,通过有限元进行仿真模拟分析。结果表明,计算所得的最大应力位置与实际断裂部位吻合,验证了过载是螺栓失效的主要原因。由此确定合理的装配力矩应不超过12 N•m,改进工艺后未再发生断裂。
The connecting bolt of locking mechanism in aircraft fractured during the repair process.To investigate the cause of the fracture,failure analysis was conducted using characterization instruments such as stereomicroscope,scanning electron microscope,metallographic microscope,and energy dispersive spectrometer.The macroscopic and microscopic morphology,micro zone composition,metallographic structure,and microhardness of the fracture surface and screw teeth of the fractured bolt were analyzed,and compared with the unbroken bolt.The results indicate that the cause of bolt fracture is overload.As there is no clear torque requirements in the process documents,in order to study the stress distribution of bolts during the tightening process and confirm scientific tightening torque values,finite element simulation analysis was conducted.It was found that the calculated maximum stress position matched the actual fracture location,verifying that overload is the main cause for bolt failure.It is determined that the reasonable assembly torque should not exceed 12 N•m,and no fracture occurs after improving the process.
作者
徐春艳
张鹏
魏振伟
阎大伟
国晨
许建亮
XU Chun-yan;ZHANG Peng;WEI Zhen-wei;YAN Da-wei;GUO Chen;XU Jian-liang(Lingyun Science&Technology Group Co.,Ltd.,Wuhan 430000,China)
出处
《失效分析与预防》
2024年第2期127-133,共7页
Failure Analysis and Prevention
关键词
螺栓
失效分析
有限元
过载
预防故障
bolt
failure analysis
finite element analysis
overload
avoid failure
