三维五向编织复合材料拉伸试样参数设计

3D five-direction braided composite tensile specimen dimension design

三维五向编织复合材料由于特殊的空间网状结构,使其具有优异的面外性能和良好的面内性能,近年来获得广泛应用。但对其建模时施加的周期性边界条件与实际进行力学性能测试时试样的尺寸间存在一定差异,未考虑到试样宽度对三维五向编织复合材料力学性能测试过程及结果的影响。本文基于三胞模型分析方法,按照与实际材料一致的比例及堆叠方式构造不同宽度的经向无缺口拉伸和纬向无缺口拉伸试样,分析不同尺寸下试样的应力分布及材料弹性性能,明确尺寸效应对三维五向编织复合材料的影响,为指导三维五向编织复合材料试样尺寸设计提供理论依据。

3D five-direction braided composites have been widely used in recent years due to their special spatial network structure.which enables them to have excellent out-of-plane properties and good in-plane properties.However,there is a certain difference between the periodic boundary conditions imposed during the modeling and the size of the sample during the actual mechanical performance test,and the influence of the sample width on the mechanical performance testing process and results of the 3D five-direction braided composite material is not considered.In this paper,based on the three-cell model analysis method,according to the proportion and stacking method consistent with the actual material,the warp unnotched tensile specimens and the weft unnotched tensile specimens of different widths are constructed,and the stress distribution and material of the specimens under different sizes are analyzed.The elastic properties and the influence of the size effect on the 3D five-direction braided composite material provide a theoretical basis for guiding the size design of the 3D five-direction braidedcompositematerial.