复合材料-钛合金多钉连接结构疲劳试验研究

Experimental Study of the Fatigue Performance in Multi Fastener Composite-to-titanium Single Lap Joints

为验证疲劳加载下复合材料-钛合金多钉连接的安全性,对其疲劳失效行为及剩余强度进行了试验研究。在试验过程中考虑了不同钉径、不同钉孔配合的影响,并综合应用应变位移跟踪、声发射及C扫描等方法对试验中以及试验后试验件的力学反应和破坏行为进行了检测分析。试验结果表明:在规定的载荷下,试验件经过6万次循环没有破坏发生,连接件安全可靠。不同钉径和钉孔配合方式对于连接的疲劳性能和钉载分配影响较小。钉径越大,连接件剩余强度越大,而钉孔配合方式对连接的剩余静强度影响较小。

Experimental study was performed in the pursuit of fatigue behavior and residual strength of composite- to-titanium single lap joints multi fastener to verify its safety. The influences of bolt diameters and clearances were taken into account. Via the approach of hole elongation tracking, acoustic emission, ultra-sonic and C-scan, the experimental results indicate no failure and no load distribution change throughout 60 000 cycles under the assigned fatigue load, which guarantes the safety of the joint ; various bolt diameters and clearances have trivial influence on the fatigue performance and load distribution during the fatigue process. The residual strength of the joint shows a inclining trend with the increase of the bolt diameters, while is affected little by the bolt clearances.