Abstract:
A finite element analysis (FEA) was conducted to examine the behaviour of single-lap quasi-isotropic (QI) and cross-ply (CP) hybrid bolted/bonded (HBB) configurations subjected to tensile shear loading. Several critical design factors influencing the composite joint strength, failure conditions, and load-sharing mechanisms that would optimise the joining performance were assessed. The study of the stress concentration around the holes and along the adhesive layer highlights the fact that the HBB joints benefit from significantly lower stresses compared to only bolted joints, especially for CP configurations. The simulation results confirmed the redundancy of the middle bolt in a three-bolt HBB joint. The stiffness and plastic behaviour of the adhesive were found to be important factors that define the transition of the behaviour of the joint from a bolted type, where load sharing is predominant, to a bonded joint. The load-sharing potential, known as an indicator of the joint\'s performance, is improved by reducing the overlap length, using a low-stiffness, high-plasticity adhesive, and using thicker laminates in the QI layup configuration. Enhancing both the ratio of the edge distance to the hole diameter and washer size proves advantageous in reducing stresses within the adhesive layer, thereby improving the joint strength.
摘要:
进行了有限元分析(FEA),以检查单搭接准各向同性(QI)和交叉层(CP)混合螺栓连接/粘结(HBB)结构在拉伸剪切载荷下的行为。影响复合材料接头强度的几个关键设计因素,失效条件,并对优化连接性能的负载共享机制进行了评估。对孔周围和沿粘合剂层的应力集中的研究突出表明,与仅螺栓连接的接头相比,HBB接头受益于显着较低的应力。特别是CP配置。模拟结果证实了三螺栓HBB接头中中间螺栓的冗余。发现粘合剂的刚度和塑性行为是定义接头从螺栓连接类型过渡的重要因素。在负载共享占主导地位的地方,连接到粘合接头。负载共享潜力,被称为关节性能的指标,通过减少重叠长度来改进,使用低刚度,高塑性粘合剂,并在QI铺层配置中使用较厚的层压板。提高边缘距离与孔直径和垫圈尺寸的比率证明有利于减小粘合剂层内的应力。从而提高了接头强度。