基于数字图像相关法的纱线和织物微观变形测量

为连续、精确地测量纱线和织物组织单元的拉伸变形量，结合数字图像相关法(DIC),提出一种微观尺度下的单轴拉伸变形测量方法。首先选取4种织物，从织物中抽取纱线、裁剪织物试样，并制作合理的散斑。然后对纱线和织物试样分别进行单轴拉伸实验并用相机记录整个过程。最后在DIC测试软件中添加引伸计，计算拉伸过程中单纱分段线应变以及织物单元结构在经、纬方向上的线应变。结果表明：单纱拉伸过程中，各处线应变增长速率不同；织物微小变形下内部结构呈非均匀变形，其中纬编针织物线圈变形不均匀性更为明显。基于DIC的微观变形测量方法揭示了纱线和织物生产、应用中的微量变形规律，为智能可穿戴电子纺织品的设计与应用提供指导。

Measurement of micro deformation of yarns and fabrics based on digital image correlation method

In order to measure the tensile deformation of yarns and structural repeat in fabrics accurately and continuously, a method for uniaxial tensile test was proposed in micro scale based on a digital image correlation method (DIC). Four types of fabric were selected, and yarn samples were acquired from the fabrics before the fabrics were cut into testing samples. A designed speckle pattern was made on each sample. As the next step, the yarn and fabric samples were subjected to uniaxial tensile tests and the whole process was recorded by camera. Extensometers were introduced in the DIC testing software to calculate the linear strain of segmented parts on single yarn and the linear strain of fabric along the warp and weft directions. The results show that the linear strain increases at different rates in each part on the yarn during the tensile process. When the fabric is stretched by small deformation, the deformation of fabric is non-uniform, especially for weft knitted fabrics. The method to measure the micro deformation based on DIC reveals the deformation patterns for yarns and fabrics in production and application, and it provides information for the design and application of intelligent wearable electronic textiles.