Abstract The fiber bundles crossovers, undulations and overlaps are inherent in the helical winding method of filament-would cylindrical structures such as composite tubes and pressure vessels. As a result, material properties will be highly affected because of the presence of these inherent defects in a structure. This research aims to evaluate the effect of these undulation regions on the local material properties and global mechanical performance of the tubes. In this article, a three-dimensional repeated unit cell (RUC) in a meso‑scale is developed to investigate the mechanical and thermal properties of the filament-wound composite tubes with different fiber bundle width. In this regard, three models of classical lamination theory (CLT), mosaic and fiber undulation were used and compared with each other. The given RUC is subjected to periodic boundary conditions (PBCs), and its mechanical and thermal behavior is studied by asymptotic homogenization theory (AHT). All the modeling steps are performed by an ABAQUS scripting interface (ASI) in the Python programming language. As an applied example, the effective material constants of a glass/epoxy tube with [ ± 45] lay-up are determined and the effects of different winding patterns are discussed. The results show that the fiber undulation model can cause up to 15.7% change in the mechanical and thermal properties of interweaved layers compared to the CLT. Moreover, the stress/strain distribution in a composite tube subjected to internal pressure is obtained. The findings of this article confirm that the global mechanical performance of cylindrical structures could be remarkably influenced by the local variations of the mechanical properties due to the fiber bundles crossovers/undulations/overlaps.

中文翻译：

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纤维束宽度对长丝缠绕圆柱结构力学性能的影响

摘要 纤维束交叉、起伏和重叠是复合管、压力容器等长丝圆柱结构螺旋缠绕方法固有的。因此，由于结构中存在这些固有缺陷，材料特性将受到很大影响。本研究旨在评估这些起伏区域对管的局部材料特性和整体机械性能的影响。在本文中，开发了一种中尺度的三维重复晶胞 (RUC)，以研究具有不同纤维束宽度的纤维缠绕复合管的机械和热性能。在这方面，使用经典层压理论（CLT）、镶嵌和纤维起伏三种模型并相互比较。给定的 RUC 受到周期性边界条件 (PBC) 的影响，并通过渐近均匀化理论 (AHT) 研究其机械和热行为。所有建模步骤均由 Python 编程语言中的 ABAQUS 脚本接口 (ASI) 执行。作为应用示例，确定了具有 [ ± 45] 叠层的玻璃/环氧树脂管的有效材料常数，并讨论了不同缠绕模式的影响。结果表明，与 CLT 相比，纤维波动模型可导致交织层的机械和热性能发生高达 15.7% 的变化。此外，还获得了承受内压的复合管中的应力/应变分布。