螺栓夹持填充孔复合材料层压板层间应力分析

为了研究含螺栓复合材料层压板连接接头的层间应力分布规律,提出了采用填充孔形式和虚拟界面层方法求解层间应力,并建立了三维有限元模型对受面内压缩载荷的螺栓夹持填充孔层压板进行分析。结果表明:层压板层间应力集中不仅发生在孔边,还会在螺栓头边缘附近出现,且夹持力越大螺栓头边缘附近的层间应力集中越严重;合理的螺栓夹持力能改善孔边应力状态,提高孔边抵抗分层的能力,但无法改善螺栓头边缘附近的层间剪切应力集中状态。因此,在进行含螺栓夹持的层压板机械连接结构孔边层间强度设计时,也要考虑螺栓头边缘的层间剪切应力集中问题,以提高复合材料结构的安全性。

Interlaminar stress analysis of filled-hole composite laminate with bolt clamping

Filled-hole form and virtual interlaminar boundary method were proposed to solve interlaminar stress to study interlaminar stress distribution law of composite laminates connector with bolts, and three-dimensional finite element model was established for analyzing the filled-hole laminate with bolt clamping under in-plane compression load. The results show that interlaminar stress concentration of laminates occurs not only at the hole edge, but also in the vicinity of bolt head edge, and the greater bolt-clamping force, the more serious interlaminar stress concentration near the bolt head edge. A reasonable bolt-clamping force can improve the stress state of hole edge, and enhance the ability to resist delamination of hole edge, but can not change the interlaminar shear stress concentration state near the bolt head edge. Therefore, to improve the safety of composite structures, the interlaminar shear stress concentration problems near the bolt head edge should be considered in the laminate mechanical joint interlaminar strength design of hole edge with bolt clamping.