捆绑纱线密度变化对经编织物复合材料性能的影响

Effect of binding yarn linear density change on properties of non-crimp fabrics composites

以30 dtex线密度捆绑纱经编织物和50 dtex线密度捆绑纱经编织物(Non-Crimp Fabrics,NCF)为原料,考察了捆绑纱线密度变化对LCM工艺中涉及到的经编织物性能的影响。结果表明:降低捆绑纱线密度有利于提高经编织物的渗透率,金相照片表明承受压缩载荷后,相比之下线密度较低的捆绑纱所占体积更小,捆绑纱处纤维体积分数更小;降低捆绑纱线密度有利于纤维间的滑移和嵌套,经编织物可以被压缩到更薄的厚度;在30~50 dtex区间内,捆绑纱线密度变化对经编织物变形后回弹效果无明显影响;与50 dtex线密度捆绑纱经编织物复合材料相比,30 dtex线密度捆绑纱经编织物复合材料0°拉伸强度降低10.1%,0°压缩强度提高21.9%,弯曲强度提高9.5%,层间剪切强度提高3.3%,0°拉伸模量提高6.3%,0°压缩模量提高11.3%,弯曲模量提高9.9%;金相照片表明30 dtex线密度捆绑纱经编织物制备的复合材料层间树脂易分布不均匀。

Using linear density of 30 dtex and 50 dtex non-crimp fabrics as raw materials,the effect of linear density change of binding yarn on the properties of non-crimp fabrics involved in LCM process was investigated.The results show that the decrease of linear density of binding yarn is beneficial to improve the permeability of non-crimp fabrics.Metallographic pictures show that the binding yarn with lower linear density has a smaller volume and the fiber volume fraction at the binding yarn is smaller.The decrease of linear density of binding yarn is beneficial to slip and nesting between fibers,and the non-crimp fabrics can be compressed to a thinner thickness.In the range of 30 dtex to 50 dtex,the change of linear density of binding yarn has no obvious influence on the springback effect of non-crimp fabrics after deformation.When the binding yarn density is reduced from 50 dtex to 30 dtex,the 0°tensile strength decreased by 10.1%,the 0°compression strength increased by 21.9%,the bending strength increased by 9.5%,the interlaminar shear strength increased by 3.3%,the 0°tensile modulus increased by 6.3%,the 0°compression modulus increased by 11.3%,and the bending modulus increased by 9.9%.Metallographic pictures show that the interlaminar resin distribution of the composites prepared by 30 dtex binding yarn is easy to be nonuniform.