Luo Bin, Xue Liyang, Wang Qingsong, Zou Peng
School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an 710072, China.
AVIC Chengdu Aircraft Industrial (Group) Company, Chengdu 610041, China.
Materials (Basel). 2024 Apr 30;17(9):2117. doi: 10.3390/ma17092117.
Hybrid bonded-bolted composite material interference connections significantly enhance the collaborative load-bearing capabilities of the adhesive layer and bolts, thus improving structural load-carrying capacity and fatigue life. So, these connections offer significant developmental potential and application prospects in aircraft structural assembly. However, interference causes damage to the adhesive layer and composite laminate around the holes, leading to issues with interface damage. In this study, we employed experimental and finite element methods. Initially, different interference-fit sizes were selected for bolt insertion to analyze the damage mechanism of the adhesive layer during interference-fit bolt installation. Subsequently, a finite element tensile model considering damage to the adhesive layer and composite laminate around the holes post-insertion was established. This study aimed to investigate damage in composite bonded-bolted hybrid joints, explore load-carrying rules and failure modes, and reveal the mechanisms of interference effects on structural damage and failure. The research results indicate that the finite element prediction model considering initial damage around the holes is more effective. As the interference-fit size increases, damage to the adhesive layer transitions from surface debonding to local cracking, while damage to the composite matrix shifts from slight compression failure to severe delamination and fiber-bending fracturing. The structural strength shows a trend of initially increasing and then decreasing, with the maximum strength observed at an interference-fit size of 1.1%.
混合粘结-螺栓连接的复合材料干涉连接显著增强了粘结层和螺栓的协同承载能力，从而提高了结构承载能力和疲劳寿命。因此，这些连接在飞机结构装配中具有巨大的发展潜力和应用前景。然而，干涉会对孔周围的粘结层和复合材料层压板造成损伤，导致界面损伤问题。在本研究中，我们采用了实验和有限元方法。首先，选择不同的干涉配合尺寸进行螺栓插入，以分析干涉配合螺栓安装过程中粘结层的损伤机制。随后，建立了一个考虑插入后孔周围粘结层和复合材料层压板损伤的有限元拉伸模型。本研究旨在研究复合材料粘结-螺栓混合接头的损伤，探索承载规律和失效模式，并揭示干涉对结构损伤和失效的影响机制。研究结果表明，考虑孔周围初始损伤的有限元预测模型更有效。随着干涉配合尺寸的增加，粘结层的损伤从表面脱粘转变为局部开裂，而复合材料基体的损伤从轻微压缩失效转变为严重分层和纤维弯曲断裂。结构强度呈现出先增加后降低的趋势，在干涉配合尺寸为1.1%时观察到最大强度。
