三维五向编织复合材料的弹性性能

根据实际编织工艺和编织预制件的细观结构模型,利用刚度等效的思想,导出了三维五向编织复合材料的刚度矩阵并计算了其弹性常数.在此基础上,对比分析了三维五向和三维四向编织复合材料的弹性常数随编织角及纤维体积分数的变化规律,讨论了编织预制件的截面尺寸对三维五向编织复合材料弹性常数的影响.结果表明,三维五向编织复合材料在保持三维四向编织复合材料良好性能的同时对纵向力学性能进行了增强;编织预制件的截面尺寸只在较小的情况下才对编织复合材料的弹性常数影响较大. 

Elastic properties for 3 dimensional and 5 directional braided composites

According to actual braiding process and the micro-structural model of braiding preform,using stiffness averaging method,the stiffness matrix of 3D&5D(3 dimensional and 5 directional) braided composites is deduced and their elastic properties are calculated.On the basis of calculation,the changing characteristics of elastic constants with the braided angle and volume fraction of fibers is described and the difference of elastic properties between 3D&5D and 3D&4D(3 dimensional and 4 directional) braided composites as well as the effect of cross-section size of performs are discussed.Numerical calculation shows that 3D&5D braided composites not only keep the certain merits of 3D&4D braided composites but also enhance the mechanical properties of axial direction or braided direction.The effect of cross-section size of braiding preform on the elastic properties of braided composites is larger only if the cross-section size is smaller.