CFRP构件抽芯铆接损伤及拉伸剪切性能

Damage and tensile shearing property on core pulling riveting for CFRP components

为了提高飞机碳纤维增强树脂基复合材料构件的铆接质量,针对飞机开敞性较差的CFRP构件,通过试验研究其单侧抽芯铆接损伤行为及拉伸剪切性能。研究结果表明:CFRP构件单侧抽芯铆接后,外观并未出现明显损伤,钉杆长度过大将造成镦头过高甚至歪斜;铆接过程中,构件受镦头挤压作用,钉孔局部发生折弯变形,产生挤压损伤,且损伤主要集中于镦头处CFRP构件的孔口外表面,钉孔直径越大,单侧铆接损伤越明显;构件的拉伸剪切力-位移响应依次呈现明显的线性增长阶段、屈服阶段和断裂破坏阶段的特征,构件的屈服和最终失效由铆钉主导,构件的失效模式均为铆钉剪切失效;构件的拉伸屈服极限随着钉孔直径的增加而提高,钉杆长度为8 mm时构件的屈服极限均大于钉杆长度为6 mm的构件。

In order to increase riveting qualities of carbon fiber reinforced polymer(CFRP)composite material components in aircraft,and also considering CFRP components with poor openness of aircraft,the damage behavior and tensile shearing property of unilateral core pulling riveting for CFRP components were investigated by tests.The results show that the obvious damage is not observed on the surfaces of CFRP components after unilateral core pulling riveting,but the excessive length of rivet shank leads to a high or even tilted upsetting head.However,during the riveting process,the components are squeezed by the upsetting head,and the local bending deformation and extrusion damage occur in the rivet hole.Moreover,those damages are mainly concentrated on the outer surface of hole for CFRP component at the upsetting head.The larger diameter of rivet hole is,the more serious damage in unilateral riveting is.The tensile shearing force-displacement response of components presents the characteristics of linear growth stage,yield stage and fracture failure stage in sequence.The yield and final failure of components are dominated by the rivets,and the failure modes of components are all rivet shear failure.At the same time,the tensile yield limit of components is improved with the increasing of the diameter of rivet hole,and when the length of rivet shank is 6 mm,the yield limit of the components is greater than that of the components with the length of rivet shank of 6 mm.