多重针织结构复合材料的制备及拉伸性能

Fabrication and Tensile Properties of the Composites Reinforced with Multilayer Knitted Fabrics

将两种不同的针织结构以一定的方向和顺序进行叠加,用玄武岩纤维纱手工缝合;将缝合与未缝合的增强体预制件采用真空辅助树脂转移模塑成型(VARTM)工艺加工成复合材料,对两种复合材料的纵纬向拉伸性能进行测试与分析.结果表明,取向度和拉伸方向上受力纱线根数的不同是造成经纬向拉伸性能差异的原因;缝合的复合材料的单位纤维体积分数的拉伸强度与模量比未缝合的复合材料大;复合材料的拉伸破坏模式说明缝合显著改善了复合材料的分层现象.

Two different knitted structures made of basalt fiber yarn were layered according to given direction and order, then sewed together with basalt fiber yarn. The preforms with and without sewing were used for manufacturing composites by vacuum assisted resin transfer molding （VARTM） process. Tensile properties of two kinds of reinforced composites were tested and analyzed along the course and wale directions. The results show that the orientation and numbers of load-bearing yarns are main reasons for influencing tensile properties in the two directions. The stitched composites have higher tensile strength and modulus per unit fibre volume percentage than those of no-stitched composites. The damage modes demonstrate that stitching plays a significant role against the delamination.