结构参数对三维机织复合材料拉伸和剪切性能的影响

The effect of structural parameters on the tensile and shear properties of 3Dwoven composites

为了研究三维机织结构参数与复合材料力学性能之间的关系,设计织造了4种不同结构的三维机织物,包括浅交直联、层层角联锁、接结纬接结和接结纬接结+衬纬纱结构,并分别将其制备成复合材料,通过材料试验机探究所得复合材料的结构参数对拉伸、剪切性能的影响。结果表明:纤维体积分数相同时,纱线的屈曲和纱线交织结构决定了复合材料的拉伸性能及尺寸稳定性。经向上,浅交直联结构复合材料拉伸性能和尺寸稳定性最佳,经纱屈曲大的接结纬接结+衬纬纱结构复合材料拉伸性能和尺寸稳定性最差;纬向上,接结纬接结结构复合材料拉伸性能和离散性最差。对比2个方向的拉伸性能发现,复合材料的纬向拉伸性能远远优于经向拉伸性能。织物的交织结构决定了剪切性能及尺寸稳定性,浅交直联复合材料的结构紧密,剪切模量最大,接结纬接结复合材料的结构疏松,剪切模量最小,而剪切强度几乎呈相反的规律。该研究明确了纤维体积分数、纱线屈曲程度、织物交织结构等结构参数对三维机织复合材料拉伸和剪切性能的影响,为三维机织复合材料的研究和应用提供了参考。

To investigate the relationship between the parameters of Three-dimensional(3D)woven structures and the mechanical properties of composites,four structures of 3D woven fabrics were prepared,including shallow cross-linked,layer-by-layer angle-interlock,"stitching weft"weft knitted and"stitching weft"weft knitted+inserted weft structures.They were prepared into composites,and by using a material testing machine,the effects of structural parameters on tensile and shear properties of the composites were explored.The results show that with the same fiber volume fraction,the yarn crimp and the interlacing structure of yarns determine the tensile properties and dimensional stability of the composites.In the warp direction,the shallow cross-linked woven composites exhibit the most excellent tensile properties and dimensional stability,while the"stitching weft"weft knitted+inserted weft reinforced composites with large warp crimp attain the worst tensile performance.In the weft direction,the structure"stitching weft"weft knitted reinforced composites still exhibit the worst tensile property and discreteness.Comparison of the tensile properties in both directions indicates that the tensile property of the composites in the weft direction is superior to that in the warp direction.The interlacing structure of the fabrics determines the shear properties and dimensional stability.The shallow cross-linked composites perform the highest shear modulus with a dense structure,while the"stitching weft"weft knitted composites with a looser structure result in a lowest shear modulus.However,the shear strength shows an almost opposite law.This study clarifies the effects of the structural parameters such as fiber volume fraction,yarn crimp degree,and fabric interlacing structure on the tensile and shear properties of 3D woven composites,providing reference for the research and application of 3Dwoven composites.