三维五向圆型编织复合材料细观分析及弹性性能预测

 基于三维圆型编织的主要工艺，系统研究了三维五向圆型编织的纱线交织结构，建立了内部单胞和表面单胞模型。推导了单胞的几何特性、编织工艺参数之间的数学关系。基于此模型，采用改进的刚度平均化方法，计算了三维圆型编织复合材料的弹性性能参数，并与实验的结果进行了对比，吻合较好。分析了编织角和纤维体积含量对弹性性能的影响，结果表明，五向圆型编织复合材料保持了四向圆型编织复合材料良好的力学性能，同时由于轴纱的加入，使得轴向的力学性能得以提高。

Microstructure Analysis and Prediction of the Elastic Properties of 3D and 5-D Tubular Braided Composites

The yarn traces of 3D and 5-D tubular braiding are analyzed systematically base d on 3D tubular braiding process, then the interior cells and surface cells are established. The geometric properties of the cells, and the relationship of the braiding parameters are deduced. Based on this model, the elastic properties of 3D tubular braided composites are deduced with the method of improved stiffness averaging and the predictions have shown a good agreement with the experiment re sults. This paper also analyzes the influence of the braiding angle and the fibe r volume fraction, and the results show that the 3D and 5-D tubular braided com posite has good mechanical properties of 3D and 4-D tubular braided composite a nd it improves the axial mechanical performance of the material by joining the a xial yarns.