缝合连接三维编织复合材料拉伸性能试验研究

研究了多种缝合方向、 搭接长度和缝合密度对缝合连接三维编织复合材料拉伸性能的影响 , 并与三维整体编织复合材料的拉伸性能进行对比。结果表明: 缝合连接三维编织复合材料与三维整体编织复合材料相比 ,拉伸强度下降了 25 %～50 % , 初始模量下降了 35 %～55 %; 搭接长度对拉伸强度和模量的影响较大 , 拉伸性能随搭接长度的增加呈现先增大后减小的特征 , 当搭接长度与试件宽度的比值在 2. 5 左右时 , 试件的拉伸性能较好 ,与未缝合的三维整体编织试件相比 , 仅下降了 25 %; 相对而言 , 中密度缝合试件的拉伸性能最优 ; 缝合方向对试件拉伸性能的影响不明显。 

Experimental investigation on tensile property of stitching joint 3D braided composites

The stitching joint 3D braided composites with various stitching direction , lap length and stitching densi2ty were experimentally studied to reveal the effect of stitching parameters on the tensile property. The tensile prop2erty of the stitching joint 3D braided composites was compared with that of 3D integral braided composites. The re2 sult s indicate that the tensile st rength and modulus of the stitching joint 3D braided composites are lower than those of 3D integral braided composites. The tensile st rength reduces about 25 %～50 % , and the initial modulus decreases 35 %～55 %. The tensile st rength and modulus are influenced by the lap length greatly. The tensile property of the composites shows the character , which the tensile property increases earlier , and then falls with the lap length increasing. When the ratio of lap length to width of the sample is about 2. 5 , the tensile property of the stitching joint 3D braided composites is bet ter , only a decrease of 25 %. The tensile property of the middle stitching density is bet ter comparatively. However the tensile property has no notable change with the stitching direction.