铝合金7B04长桁及2B06支架开裂失效分析  

Failure Analysis of Cracking in 7B04 Aluminum Alloy Stringer and 2B06 Bracket

作　　者：宋体杰 王珏[1] 孙梦梦 康凯[1] 王琳[2] 于妍妍 SONG Ti-jie;WANG Jue;SUN Meng-meng;KANG Kai;WANG Lin;YU Yan-yan(Shenyang Aircraft Industrial Group Co.,Ltd.,Shenyang110850,Liaoning,Chian;College of Mechanical Engineering,Inner Mongolia University of Technology,Hohhot 010051,Inner Mongolia,China)

机构地区：[1]沈阳飞机工业集团有限公司,辽宁沈阳110850 [2]内蒙古工业大学机械工程学院,内蒙古呼和浩特010051

出　　处：《铸造》2025年第1期68-74,共7页Foundry

摘　　要：针对某型铝合金长桁及支架在振动环境中开裂失效的问题,结合现场调查、宏观形貌检测、微观检测、开裂过程推演和受力情况有限元模拟等,全面分析开裂模式和原因。结果表明:根据宏观断口及显微断口中疲劳特征形貌,可判定长桁开裂起始位置在支架安装背侧面的安装孔上方附近,裂纹扩展由背侧向支架安装侧单向扩展;支架上存在两条裂纹,均呈双向扩展特点;有限元仿真结果表明,应力集中位置与裂纹起始位置基本一致,沿着支架自由端法向的循环载荷是导致两零件同时开裂的主要外部载荷。确定长桁及支架开裂模式为高周疲劳开裂。To address the cracking failure of a certain type of aluminum alloy stringer and bracket under vibrational conditions,a comprehensive analysis was conducted,incorporating on-site investigation,macrostructural examination,microstructural analysis,crack propagation inference,and finite element simulation of the stress conditions.The results indicate that based on the fatigue fracture features observed in both the macro and microfracture surfaces,the crack initiation point of the stringer was located near the upper area of the mounting hole on the rear side of the bracket installation.The crack propagated unidirectionally from the rear side toward the bracket installation side.Two cracks were observed on the bracket,both exhibiting bidirectional propagation characteristics.Finite element simulation results showed that the stress concentration area coincided with the crack initiation point,and the cyclic load along the normal direction of the free end of the bracket was the primary external load causing simultaneous cracking of the two components.The cracking mode of the stringer and bracket was identified as high-cycle fatigue failure.

关 键 词：铝合金 长桁 支架 开裂 失效分析 

分 类 号：TG245[金属学及工艺—铸造]