柔性多轴向经编聚氨酯涂层织物的拉伸性能

摘要

In order to study on the reinforcement properties of PU⁃coated multi⁃axial warp knitted fabric, five directions with 0 ° , 22�5 ° , 45 ° , 67�5 ° and 90 ° of this material were cut for uniaxial tension experiment. The tensile curves and the elastic modulus were analyzed. The deformation behaviors were observed and Poisson′s ratios were calculated by utilizing the digital image correlation ( DIC ) system. Lastly, orthotropic model was used to predict the elastic modulus and Poisson′s ratio in 22�5° and 67�5° directions. It is found that this coated fabric has a great elongation with more than 400% in five directions. And the closer to 67�5° is, the greater of the elastic modulus is. At the beginning of tensile, it can be obtained by the DIC system that the transverse shrink deformations are inhomogeneous, it shrinks faster in the center but slower at the edge of the specimens, but the longitudinal tensile deformation is relatively uniform. There is a good prediction of the elastic modulus and Poisson′s ratio by using orthotropic model, and the absolute error value is less than 23�69%.%为获得多轴向经编聚氨酯涂层织物的各向增强性能，沿涂层织物0°、22�5°、45°、67�5°和90°5个方向裁取试样，以单轴拉伸试验为基础，分析了织物的拉伸曲线和弹性模量；同时采用数字图像相关系统（ DIC），分析了织物的形变特征，计算了泊松比。利用正交各向异性模型对22�5°和67�5°方向的弹性模量和泊松比进行预测。结果表明：该材料具有良好的延伸性，各个方向试样的延伸度均大于400％；越接近67�5°弹性模量越大；由DIC云图分析得知，拉伸初期该材料的横向收缩变形是不均匀的，中间收缩较快，边缘收缩得较慢，而纵向拉伸变形相对均匀；使用正交各向异性关系对涂层织物的弹性模量和泊松比有较准确的预测，误差的绝对值都小于23�69％。