三维机织复合材料的连接性能与失效机制

Connection performance and failure mechanisms of three-dimensional woven composites

为了研究织物结构对三维机织复合材料连接性能的影响,设计了多层多向机织结构和层联机织结构复合材料,建立了开孔连接结构宏细观耦合分析模型,揭示了三维机织复合材料连接失效机制。研究表明:±45°纱所占的比例对复合材料机械连接的挤压强度具有重要影响,±45°纱线的引入,可以提高承载纱线的含量,能够有效改善孔边的应力集中现象;多层多向机织复合材料主要发生0°纱、90°纱和斜向纱的横纵向的损伤,损伤最初发生在孔边并逐渐扩展且呈对称分布,载荷的传递方向和损伤的传播方向呈现角度的特征。

In order to study the influence of fabric structures on the connection performance of three-dimensional woven composites,multi-layer multi-directional woven structure and layer-to-layer interlock woven structure composites were designed,and a macro-meso coupling analysis model of the open-hole connection structures was established to reveal the failure mechanism of 3D woven composite connections.The study shows that the proportion of±45°yarn has an important effect on the extrusion strength of the mechanical connection of the composite material,and the introduction of±45°yarns can improve the content of load-bearing yarns,which can effectively improve the stress concentration at the hole edge;the multi-layer multi-directional woven composites are mainly subjected to transverse and longitudinal damages of 0°yarn,90°yarn,and bias yarns;these damages start at the hole edge and progressively spread symmetrically.The transmission direction of load and the propagation direction of damage show angular characteristics.