基体中含有随机分布裂纹的纤维增强复合材料的总体弹性常数

本文应用自洽方法计算了含随机分布裂纹的基体的等效弹性常数,然后利用GMC方法计算了复合材料的总体弹性常数.结果表明,随着裂纹密度的增加,基体的等效弹性模量和泊松比会降为零;而同时,复合材料的纤维方向的弹性模量的下降,但是仍然能达到没有裂纹时的90%.这表明当基体完全破坏的时候,纤维仍能够在纵向承受载荷.另外,当基体的等效弹性模量和泊松比会降为零时,复合材料的横向弹性模量和剪切模量都接近为零,表明这时复合材料无法承受横向的拉压力和剪切力.

GLOBAL ELASTIC CONSTANTS OF FIBER REINFORCED COMPOSITES WITH RANDOM DISTRIBUTION CRACKS IN MATRIX

The effective elastic constants of the matrix with random distribution cracks are obtained by means of the self-consistent method,then generalized method of cells is used to get the global elastic constants.It is shown that with the increase of the crack density,the effective elastic module and the Poisson's ratio will decrease to zero.At the same time,the elastic module of the composite along the fiber will decrease,but still can be 90% of that with no cracks.That means when the matrix is entirely broken,the fiber can still endure the longitudinal load.What's more,with the increase of the crack density,the transverse elastic module and the transverse shear module will decrease to zero,which means the composite can't withstand the transverse tension and shear.