异型截面三维编织复合材料细观结构分析

阐述了异型截面三维编织物编织的基本原理,以"口"字型截面为例,系统地分析了携纱器在机器底盘上的运动规律以及纱线在面内和空间的交织运动规律.采用控制体积单元法建立了异型截面三维编织复合材料中除普通方型三维编织复合材料所具有的内胞、面胞和角胞外,在矩形与矩形相连区域的相连内部单胞、相连表面单胞和相连角单胞模型.这些单胞模型的表面与预制件的表面平行,有利于今后的力学性能分析.此外,在假设纱线具有椭圆形横截面的基础上,推导了编织工艺参数之间的数学关系,为进一步分析异型截面三维编织复合材料的力学性能奠定了基础. 

Micro-structural analysis of three dimensional braided composites with profiled section

The fundamental theory of braiding process of three dimensional braided preform with profiled section was described. The movement rules of the carriers in the machine plane and the planar and spatial yarns paths were analyzed systematically based on the preform with square section. The unit models in the joint rectangle region of interior, surface, and corner of three dimensional braided composites with profiled section were established besides the unit model of interior, surface, and corner of three dimensional rectangular braided composites by means of a control volume method. The surface of these models is parallel to the surface of perform, which is suitable for the analysis of the mechanical properties. In addition, the math relationship between braiding parameters was deduced on the hypothesis of the yarns with the elliptical cross-section. It would be a solid base for the analysis of the properties of three dimensional braided composites with profiled section.