摘要:
根据三维正交机织复合材料中纤维束的空间几何特征,提出了改进的单胞模型,此模型包含经纬纱正交单胞、接结经单胞与接触单胞3种结构。考虑到各个单胞中的纤维束空间结构与变形特点,对纤维束截面尤其是对挤压处的纤维束进行了合理等效,以达到模型通用和简化计算目的。基于均匀化方法分别求得各单胞弹性常数,进一步运用刚度平均化方法获得三维机织复合材料的工程弹性常数。数值结果与实验结果对比表明新建模型的预测精度较好,且相同纤维体积含量情况下,横向弹性模量随机织角的逐渐增大而增大但纵向弹性模量减小。
Abstract:
An improved three-cell model,which includes warp-weft cell,warp tying cell and contact cell,is proposed based on the geometry characteristics of the yarns for 3D orthogonal woven composite. The deformation and structural characteristics of yarns in cells are considered. The cross-section of yarns,especially extrusion yarns,is equivalently deal with so that the present model is common and the corresponding calculation is simple. The effective elastic properties of cells are obtained by using the homogenization method. Then based on the stiffness volume average method,the elastic stiffness of 3D orthogonal woven composite is calculated. Comparing with the available experimental data,the result of numerical example shows the present model is effective and reasonable. Also,the effect of the woven angle on the elastic stiffness of 3D orthogonal woven composite is discussed,i. e.,the increase of the woven angle leads to the increase of the transverse modulus and the decrease of the longitudinal modulus.