三维编织复合材料剪切性能分析

根据三维四向编织复合材料的结构特点，提出了刚度合成法预测编织复合材料剪切弹性模量，比较了整体编织试件和裁剪所得试件理论剪切性能差别，分析了三维编织T300／QY9512复合材料的剪切性能随试件沿宽度和厚度两个方向内部单胞数目的变化规律。结果表明，三维编织复合材料剪切弹性模量是与试件尺寸相关的，只有当试件尺寸较大、沿宽度和厚度两个方向内部单胞数目较多时，试件尺寸的影响可以忽略。当沿宽度方向单胞数目较大时，整体编织试件和裁剪所得试件的剪切模量相近。本文还得到了在复合材料板的纤维体积含量不变的情况下，剪切模量随编织角的变化规律。

Shear Property Analysis of Three-Dimensional Braided Composite

According to material structure of 3-D braided composites, we proposed a method of stiffness combination to predict shear properties. This paper conducted a analysis of 3-D braided T300/QY9512 composite's shear character with change of specimens' width and height. Result indicates that specimen's shear modulus can be got using stiffness combination method. Specimen's shear modulus is relative to specimen's dimensions. It is only when the number of inner unit cells in both width and height directions is large enough Specimen's shear modulus is nearly a constant. We also analyzed the change of shear modulus of specimen with the change of the braiding angle.