CFRP构件带垫圈铆接损伤及剪切性能

碳纤维增强树脂基复合材料(CFRP)在航空领域应用广泛,但极易发生铆接损伤。因此,针对航空CFRP构件,本文通过试验方法研究带垫圈铆接损伤行为,评估不同宽径比和宽径比西铆接构件拉伸剪切性能,研究结果表明：CFRP铆接损伤主要由镦头径向过度膨胀和镦头材料轴向变形挤压造成,以挤压损伤为主,带限制垫圈铆接可有效减少铆接损伤,其损伤主要发生在镦头附近层板孔周附近表层局部区域,由垫圈内孔附近区域挤压下凹造成；所有试件力-位移响应曲线特征由钛合金铆钉主导,呈现出明显弹性变形阶段、塑性变形阶段和最终失效阶段,最终失效模式均为铆钉剪切失效；拉伸失效过程中,垫圈均未发生明显变形,CFRP层板钉孔周围表层发生明显局部挤压损伤,拉伸过程中伴随纤维断裂声响；宽径比对试件刚度和最终失效强度均具有明显影响,而边径比对试件力-位移响应影响不明显。

Damage and Tensile Shearing Property Investigation of CFRP Riveted Joints with Gaskets

Carbon fiber reinforced polymer composites (CFRP) are widely used in aeronautic industry, however, CFRP is prone to be damaged during riveting. Therefore, the riveting damage behaviors of the CFRP riveted joint with a gasket were investigated experimentally in this paper. The tensile shearing properties of joints were also evaluated. The results demonstrated that the riveting damage was dominated by bearing damage caused by uneven deformation of rivet tail. The gasket was useful in reducing riveting damage, and the damage only occurred at the local area in the surface of CFRP riveting hole, which was caused by the depression of gasket. The load-displacement curves were dominated by rivets, and exhibited elastic deformation stage, plastic deformation stage, and final failure stage. All specimens failed in rivet shearing failure mode. During tensile shearing testing, the gasket was un-deformed, and only local bearing damage occurred at the local region near the hole of CFRP, moreover, the fiber tensile fracture noise can also be heard. The width to diameter ratio exhibited an obvious influence on load-displacement responses of joints, while edge displacement to diameter ratio had little influence on load-displacement responses of joints.