Experimental study on mechanical properties and failure behavior analysis of CFRP riveted joints with gaskets and bushings

垫圈和衬套类CFRP铆接接头力学性能的实验研究及失效行为分析

¹ School of Mechanical Engineering, Northwestern Polytechnical University, Xi′an 710072, China
² AVIC Xi′an Aircraft Industry Group Company Ltd., Xi′an 710089, China
³ NPU Xuhang Electromagnetic Technology Co., Ltd., Xi′an 710100, China

Received: 11 May 2024

Abstract

The application of gaskets, bushings or their combination can significantly improve the joining strength of composite structures, but there is still a lack of systematic researches on their combined or individual applications. To solve this problem, this paper reported a comparative assessment on the joint strength and failure behavior of carbon fiber reinforced polymer(CFRP) joints with different combination of gaskets and bushings, i.e., riveting, gasket riveting, bushing riveting and gasket-bushing riveting. The results show that gasket riveting can improve the ability of the joint to absorb energy and resist damage by increasing the load-bearing area and the extrusion deformation of the gasket, so that the joints can obtain the highest strength. This combination also limits secondary bending and delay the damage of the joints, the failure mode of the joints is extrusion failure. Besides, the size of the rivets used in bushing riveting is small, which leads to a decrease in the joint′s resistance to damage and energy absorption. The average joining strength of the specimens is minimal, and the failure mode is a mixed extrusion-pull-off failure. At last, although the gasket-bushing riveting method cannot improve the joints′ ability to resist damage, it can greatly improve the joint′s energy absorption capacity and joining strength.

摘要

垫圈、衬套或其组合对复合材料结构的铆接质量有重要影响, 但目前缺乏对其安装工艺系统研究。通过对铆接接头的准静态拉伸试验对比研究了净铆接、垫圈铆接、衬套铆接和垫圈+衬套组合铆接4种工艺下碳纤维增强树脂基复合材料(CFRP)铆接接头的连接强度和失效行为, 系统评估了不同铆接工艺对接头失效模式的影响。结果表明, 垫圈铆接可通过增大承载面积和垫圈的挤压变形提高接头吸收能量和抵抗损伤的能力, 使接头获得最高的强度, 同时限制次弯曲延缓接头的破坏, 使接头失效模式表现为挤压失效；衬套铆接所使用的铆钉尺寸小, 导致接头抵抗损伤和能量吸收能力下降, 接头强度最小, 失效模式为挤压-拉脱混合失效；垫圈+衬套铆接方法虽不能提高接头抵抗损伤的能力, 但可使接头能量吸收能力和接头强度大幅提高。