This paper presents a non-linear, large strain constitutive approach to modelling the mechanics of fibrous tows. The isotropic and linear St. Venant hyperelastic model was modified to extend its applicability to a transversely isotropic continuum. From this model, a set of large-strain material parameters which resemble the linear-elastic moduli was derived. The non-linear constitutive response of fibrous tows was accounted for through a modelling scheme that incorporates the instantaneous microstructural arrangement of the tows. Tow samples were isolated from the studied textile roll and subjected to a compression study utilising a custom-made tow compression rig, from which a set of material functions that fully defined the constitutive model were generated. The developed model was then implemented as a material subroutine and utilised in a mesoscopic compaction simulation of a multi-layer 2D woven reinforcement. It was found that the constitutive model performed very well in predicting the shape changes and stresses in deforming tows.

本文提出了一种非线性的大应变本构模型来模拟纤维束的力学。修改了各向同性和线性的St​​. Venant超弹性模型，以将其适用性扩展到横向各向同性连续体。从该模型中，导出了一组类似于线性弹性模量的大应变材料参数。纤维束的非线性本构响应是通过一种建模方案来解决的，该方案结合了纤维束的瞬时微结构排列。从被研究的纺织卷中分离出丝束样品，并使用定制的丝束压缩装置进行压缩研究，由此产生了一套完全定义本构模型的材料功能。然后将开发的模型作为材料子例程实施，并用于多层2D编织增强材料的介观压实模拟。发现本构模型在预测变形丝束的形状变化和应力方面表现非常好。