三维全五向编织复合材料的切边效应  

Cut-edge effect of three-dimensional full five-directional braided composites

作　　者：刘振国[1] 黄祥[1] 亚纪轩 雷冰[1] 李小康[1] 程新[2] 

机构地区：[1]北京航空航天大学航空科学与工程学院,北京100083 [2]西安航天复合材料研究所,西安710025

出　　处：《航空学报》2017年第8期92-103,共12页Acta Aeronautica et Astronautica Sinica

摘　　要：对切割与未切割的三维全五向(3DF5D)编织复合材料进行了纵向拉伸力学性能研究。首先分别对2种编织角下3种不同情况(未切割、沿厚度方向切边和沿宽度方向切边)的试件进行了力学性能实验,实验结果表明,沿着厚度方向切边使材料的刚度和强度分别下降了约10%和25%;沿着宽度方向切边使材料刚度和强度分别下降了约3%和18%;进一步通过有限元数值模拟对上述实验过程进行了仿真计算,得到了单胞的损伤演化过程、破坏机理以及应力-应变曲线。最后对实验结果和计算结果进行了对比,结果显示二者吻合良好。研究结果表明,三维全五向编织复合材料的编织角越大,拉伸刚度和强度会越小;试件尺寸越大,厚度方向和宽度方向切边的影响越小,并趋于定值。Experimental research on cut-edge and uncut-edge effects of the mechanical performance of three-Dimensional Full five-Directional（3DF5D）braided composites is conducted.The specimens include two different braiding angles and three different cutting ways（uncut-edge,cut along the thickness direction and cut along the width direction）.The mechanical performances of the specimens are obtained and studied to get the conclusion of the cut-edge influence.It is found that for the specimen cut along the thickness direction,there is approximately 10% reduction in average stiffness and 25% reduction in average strength,compared with specimens without cut-edge;while for the specimen cut along the width direction,the stiffness and strength decrease by 3% and 18%,respectively.The progressive damage and failure process of mesoscopic braided structures are investigated based on the repeated unit cells,and then the stress-strain curve of the specimen is obtained.Good agreement is obtained between the numerical and experimental results.Results show that the tensile stiffness and strength decrease with the increase of the braiding angle.The cut-edge effect on the performance of full 5-directional braided composites performance weakens and comes close to a constant with the increase of inner cells.

关 键 词：三维全五向 编织角 切边效应 实验研究 力学性能 

分 类 号：V258.3[一般工业技术—材料科学与工程] TB332[航空宇航科学与技术—航空宇航制造工程]