Slender fibrous assembled structures can easily buckle under longitudinal compressive load. The limitation in characterizing the longitudinal compression behavior poses a significant challenge to the mechanics optimization of such structures. To address this challenge, we use one-dimensional yarns as a model system, and the yarns are deformed in bending to form a strain gradient, from tension to compression, along the radial direction of the yarns. The compression modulus as a function of compression strain is calculated based on bi-moduli elastic theory. The evolution of the fiber arrangement and the position of the neutral layer in the yarn is interpreted along with the change of compression modulus. Also, the local stress distribution in the bent yarn was determined by finite element simulation, and it is remarked that the bending property of yarns is sensitive to the compression modulus. The present study offers insights on the modeling and simulation of fabrics and garments in drape and bending deformation. Results from such investigations can provide effective guidance for the mechanical and structural design of textiles and textile-based composites.

细长的纤维组装结构在纵向压缩载荷下很容易弯曲。表征纵向压缩行为的局限性对此类结构的力学优化提出了重大挑战。为了应对这一挑战，我们使用一维纱线作为模型系统，纱线在弯曲时变形，形成沿纱线径向从拉伸到压缩的应变梯度。基于双模量弹性理论计算作为压缩应变函数的压缩模量。纤维排列的演变和纱线中中性层的位置随着压缩模量的变化而被解释。此外，弯曲纱线中的局部应力分布是通过有限元模拟确定的，并指出纱线的弯曲性能对压缩模量很敏感。本研究为织物和服装的悬垂和弯曲变形的建模和模拟提供了见解。此类调查的结果可为纺织品和纺织品基复合材料的机械和结构设计提供有效指导。