单层编织增强复合材料力学特性计算

单层编织增强复合材料具有优异的比强度、比刚度和变形特性,逐渐被应用于空间可展结构。其一般采用薄壳形式,应用基于均匀化ABD刚度矩阵的壳体理论可提高结构计算效率。对于非对称编织增强物,如按经典复合材料理论计算,中性面偏移会导致不准确的耦合效应。本文提出了一种基于单胞模型的多尺度方法,通过确定中性面并施加周期边界条件,计算任意单层编织复合材料的ABD刚度矩阵和模量值。对比试验验证了方法的准确性,预测了平纹、破斜纹1/3、斜纹1/3编织增强复合材料刚度及模量随编织密度的变化趋势,给出了单胞的合理应变分布。

Calculation of Mechanical Properties for Single-Ply Weave-Reinforced Composites

Single-ply weave-reinforced composites have been gradually applied to deployable space structures because of their excellent specific strength, specific stiffness, and deformation characteristics. Generally, the space structures made of single-ply weave-reinforced composites are thin shells. It is computationally efficient to analyze these structures with the shell theory based on the homogenized ABD stiffness matrix. For asymmetrical weave-reinforced materials, the shift of the neutral plane will lead to inaccurate coupling effects if the calculations are according to the classical laminate theory. In this paper, a multi-scale method based on the representative volume element (RVE) is proposed, with which the homogenized ABD stiffness matrix and modulus of any single-ply weave-reinforced composite can be calculated accurately. Comparative experiments verify the correctness of the proposed method, predict the trends of stiffness and modulus of plain, broken 1/3, and twill 1/3 weave-reinforced composites with different weaving densities, and provide the reasonable strain distribution of the RVE.