This contribution presents an approach to generate unit-cell models of structural stitched non-crimp fabric composites. Resin-rich regions and out-of-plane undulations caused by the stitching yarn are represented by initially straight discretised lines, while the stitching yarn is represented initially by a single discretised line which can be transformed into a multi-line configuration to model stitch cross-section variations. The discretised lines are shaped by geometrical operations with a contact treatment and boundary conditions being used to account, respectively, for line interactions and to control the shape of the bottom and top surfaces of each lamina respectively. A fiber-reinforced distorted zone with local variations in fiber volume fraction and fiber direction is modelled in cross-sections of the lamina in a post-processing step. Models for different stacking sequences and stitching parameters are then automatically generated and subsequently being in the stiffness calculation and damage initiation assessment using finite element based mechanical simulations.

中文翻译：

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用于评估结构缝合非卷曲织物复合材料中微损伤起始的自动 RVE 计算

这一贡献提出了一种生成结构缝合非卷曲织物复合材料的单元模型的方法。由缝合纱线引起的富含树脂的区域和平面外波动由最初的直线离散线表示，而缝合纱线最初由一条离散线表示，该线可以转化为多线配置以模拟十字绣-部分变化。离散线通过几何运算形成，接触处理和边界条件分别用于说明线相互作用并分别控制每个层的底面和顶面的形状。在后处理步骤中，在层的横截面中模拟了纤维体积分数和纤维方向局部变化的纤维增强扭曲区域。