二步法方型三维编织复合材料力学性能及影响因素

RESEARCH ON THE MECHANICAL PROPERTIES AND THE EFFECTORS OF THE TWO-STEP 3D BRAIDED COMPOSITES

对具有不同细观结构参数的二步法方型三维编织复合材料试件进行了轴向拉伸、三点弯曲及轴向压缩的力学性能测试,获得了这种结构材料的基本力学性能数据。针对其细观结构特点,从宏观角度分析了编织纱的种类、编织纱与轴纱的线密度之比以及编织节距长度等参数对力学性能的影响。实验和分析结果表明:二步法方型三维编织复合材料的轴纱对轴向拉伸和压缩性能起主导作用;节距长度增大,编织纱越粗,轴向拉伸强度、拉伸模量以及轴向压缩强度和模量均有增大的趋势。

This paper presents the results of an experimental study conducted on the mechanical property of the two-step rectangle 3D braided composites. The tests include tensile in the axis, flexure and compression in the axis. Thus, the reliable mechanical property data are obtained. On the basis of the character of the microstructure, this paper relates the influence of microstructural variables such as the kinds and sizes of braider yarns, the linear density ratios of axial to braider yarn and the pitch lengths on the mechanical properties of these composites from a macroscopical view. It shows that the axial yarns dominate the tension and compression properties in the axial direction. The strength and modulus of tension and compression in the axial direction increase with the pitch length and size of braider increasing.