Hu Chunxing, Huang Guibin, Li Cheng
School of Mechanical and Power Engineering, Zhengzhou University, Science Road 100, Zhengzhou 450001, China.
Materials (Basel). 2021 Feb 21;14(4):1016. doi: 10.3390/ma14041016.
To investigate the mechanical behavior of the single-lap joints (SLJs) adhesively bonded structure of carbon fiber reinforced polymer (CFRP) laminates under the low-velocity impact (LVI) and tensile-after impact (TAI), tests and simulations were carried out. A finite element model (FEM) was established based on the cohesive zone model (CZM) and Hashin criterion to predict the damage evolution process of adhesive film, intra- and inter-laminar of the SLJs of CFRP laminates, and its effectiveness was verified by experiments. Moreover, three different overlap lengths (20 mm, 30 mm, and 40 mm) and four different impact energies (Intact joint, 10 J, 20 J, and 30 J) are considered in the present study. Finally, the effects of different impact energies and overlap lengths on the residual strength of SLJs after impact were discussed. The results divulged that numerical results of impact and TAI processes of SLJs were in good agreement with experiment results. During the impact process, the damage of the laminates was primarily fiber and matrix tensile damage, whereas the adhesive film was damaged cohesively; the areas of damage increased with the increase of impact energy, and the normal stress of the adhesive film expanded from the edge to the middle region with the increase of impact force. The influence of LVI on SLJs adhesively bonded structures was very significant, and it is not effective to obtain a higher impact resistance by increasing the overlap length. For the tensile process, the failure mode of TAI of the SLJs was interface failure, the surplus strength of the SLJs gradually decreased with the increase of the impact energy because of the smaller overlap length, the overlap length more than 30 mm, and the low energy impact has almost no effect on the residual strength of the SLJs.
为了研究碳纤维增强聚合物（CFRP）层压板单搭接接头（SLJ）粘结结构在低速冲击（LVI）和冲击后拉伸（TAI）作用下的力学行为，进行了试验和模拟。基于内聚力模型（CZM）和Hashin准则建立了有限元模型（FEM），以预测CFRP层压板SLJ的胶膜、层内和层间损伤演化过程，并通过实验验证了其有效性。此外，本研究考虑了三种不同的搭接长度（20 mm、30 mm和40 mm）和四种不同的冲击能量（完整接头、10 J、20 J和30 J）。最后，讨论了不同冲击能量和搭接长度对冲击后SLJ残余强度的影响。结果表明，SLJ冲击和TAI过程的数值结果与实验结果吻合良好。在冲击过程中，层压板的损伤主要是纤维和基体拉伸损伤，而胶膜则发生粘结破坏；损伤面积随冲击能量的增加而增大，胶膜的正应力随冲击力的增加从边缘向中间区域扩展。LVI对SLJ粘结结构的影响非常显著，通过增加搭接长度来获得更高的抗冲击性是无效的。对于拉伸过程，SLJ的TAI破坏模式为界面破坏，由于搭接长度较小，SLJ的剩余强度随冲击能量的增加而逐渐降低，搭接长度超过30 mm，低能量冲击对SLJ的残余强度几乎没有影响。
