湿热环境下钉孔间隙对复合材料螺栓连接结构静力失效的影响  

Effects of Bolt-Hole Clearance on Static Tensile Failure of Composite Bolted Joints Under Hygrothermal Environment

作　　者：武涛 任鹏 朱兆轩 方嘉晨 耿亚南 Tao Wu;Peng Ren;Zhaoxuan Zhu;Jiachen Fang;Yanan Geng(College of Transportation Science and Engineering,Civil Aviation University of China,Tianjin 300300,China;College of Aeronautical Engineering,Civil Aviation University of China,Tianjin 300300,China;Aerospace Technology Research Institute,China Air Power Research and Development Center,Mianyang 621000,China)

机构地区：[1]中国民航大学交通科学与工程学院,天津300300 [2]中国民航大学航空工程学院,天津300300 [3]中国空气动力研究与发展中心空天技术研究所,四川绵阳621000

出　　处：《高分子材料科学与工程》2024年第10期97-108,共12页Polymer Materials Science & Engineering

基　　金：天津市教委科研计划项目(2021KJ054)。

摘　　要：湿热环境对复合材料连接结构的性能有较大影响。在25℃干态(RTD)和70℃平衡吸湿(ETW)2种环境条件下开展静力拉伸试验,分析了0 mm,0.2 mm和0.4 mm这3种钉孔配合间隙的复合材料螺栓连接静强度变化规律,结合扫描电镜试验揭示了接头的微观失效机理,并建立有限元模型分析了不同钉孔间隙试件的孔周应力状态。结果表明,钉孔间隙和湿热环境均对结构强度有显著影响,相较于0 mm间隙的试件,0.2 mm和0.4 mm试件在RTD环境中的极限失效载荷分别降低了2.78%和3.45%,在ETW环境中的极限失效载荷分别降低了4.64%和5.01%;分别对比0 mm,0.2 mm和0.4 mm钉孔间隙的试件,ETW环境中的极限载荷较RTD环境中分别下降了9.34%,11.07%和10.81%;ETW环境中层合板孔周的损伤更为严重,基体断裂面比较粗糙,裂纹也更加明显,且存在更明显的纤维束拔出及纤维碎裂,在层合板厚度方向可以发现黏附的树脂较少,纤维分布形貌较为平整。The hygrothermal environment has a significant impact on the mechanical properties of composite bolted joints.In this paper,static tensile tests were carried out under two environmental conditions:room temperature and dry(RTD)and 70℃equilibrium moisture absorption(ETW),to analyze the static strength variation laws of composite bolted joints with three different pin-hole clearances of 0 mm,0.2 mm,and 0.4 mm.Combined with scanning electron microscopy(SEM)test,the microscopic failure mechanism of the joints was revealed,and a finite element model was established to analyze the stress state around the holes of specimens with different pin hole clearances.The results show that both pin-hole clearance and hygrothermal environment have significant effects on structural strength.Compared with the specimens with a 0 mm clearance,the ultimate failure loads of the specimens with 0.2 mm and 0.4 mm clearances are decreased by 2.78%and 3.45%,respectively,under the RTD condition,and by 4.64%and 5.01%,respectively,under the ETW condition.By comparing the specimens with 0 mm,0.2 mm,and 0.4 mm clearances,the ultimate loads under the ETW condition are decreased by 9.34%,11.07%,and 10.81%,respectively,compared with those under the RTD condition.The damage around the holes in ETW environment is more severe,while the fracture surface of the substrate is relatively rough,the cracks are more obvious.And it could also find some fiber bundle pulling and fiber fragmentations.In the thickness direction of the laminated board,it could be noticed that there is less adhesive resin,and the fiber distribution morphology is relatively flat.

关 键 词：复合材料 湿热环境 钉孔间隙 螺栓连接 单钉单剪 静力失效 

分 类 号：TH131.3[机械工程—机械制造及自动化]