Jansson Anton, Pejryd Lars
School of Science and Technology, Örebro University, 701 82 Örebro, Sweden.
Heliyon. 2019 Feb 5;5(2):e01200. doi: 10.1016/j.heliyon.2019.e01200. eCollection 2019 Feb.
In this work, aluminium-carbon-fibre reinforced plastic joints have been studied. Three types of samples were designed as double lap joints where the aluminium inserts were fabricated using both classical methods (milling) and additive manufacturing. Two versions of the joint were fabricated using additive manufacturing, one flat, and the other with small teeth designed to hook into the carbon-fibre plies. The joints were characterised using a non-linear, dual-energy computed tomography method to evaluate the bond between the composite and the metal inserts. The mechanical strength of the bonds was evaluated, both through tensile tests and four-point bending. A simple finite element model was used to discuss the joints behaviour. It was found that the joints fabricated using additive manufactured inserts were more resistant to peel stress than the milled inserts. In four-point bending tests the moment that the joint could withstand was increased by roughly 300% with the use of additive manufacturing and 400% with the use of additive manufacturing and small teeth. However, in tensile tests it was found that the teeth design reduced the maximum load capacity of the joints by roughly 30% due to porosity. Further, it was found that the additive manufactured samples did not add to the capability of withstanding shear stress. The information gained with the dual-energy computed tomography method was highly valuable as the behaviour of the joints would have been difficult to explain without the porosity information.
在这项工作中，对铝 - 碳纤维增强塑料接头进行了研究。设计了三种类型的样品作为双搭接接头，其中铝制插入件采用经典方法（铣削）和增材制造两种方式制造。使用增材制造制造了两种接头版本，一种是平的，另一种带有设计用于钩入碳纤维层的小齿。使用非线性双能计算机断层扫描方法对接头进行表征，以评估复合材料与金属插入件之间的结合情况。通过拉伸试验和四点弯曲试验对接头的机械强度进行了评估。使用简单的有限元模型来讨论接头的性能。结果发现，使用增材制造的插入件制造的接头比铣削的插入件更能抵抗剥离应力。在四点弯曲试验中，使用增材制造时接头能够承受的弯矩增加了约300%，使用增材制造和小齿时增加了400%。然而，在拉伸试验中发现，由于孔隙率，齿形设计使接头的最大承载能力降低了约30%。此外，发现增材制造的样品在承受剪切应力方面没有优势。通过双能计算机断层扫描方法获得的信息非常有价值，因为如果没有孔隙率信息，接头的性能将很难解释。
