Abstract: To solve the problem of time-consuming and labor-intensive prediction of the mechanical properties and appearance effects of fabrics by enterprises through weft knitted plain weave and sampling, a method using ABAQUS finite element analysis to predict the mechanical properties of fabrics was proposed. Firstly, the yarn and fabric were photographed by using the Axio Cam Erc 5S Zeiss polarizing microscope at different zoom angles to obtain the geometric parameters of the fabric coil. 19 feature points of the coil for three times of NURBS curve fitting were selected, the coil center curve was obtained, and the obtained geometric parameters were used to establish a fabric model. According to GB/T 3916-2013 "Textiles—Yarns from Packages—Determination of Single-end Breaking Force and Elongation at Break Using Constant Rate of Extension(CRE) Tester", GB/T 3923.1-2013 "Textiles—Tensile Properties of Fabrics—Part 1: Determination of Maximum Force and Elongation at Maximum Force Using the Strip Method", and GB/T 19976-2005 "Textiles—Determination of Bursting Strength—Steel Ball Method", tensile and breaking tests were conducted on fabrics. Then, ABAQUS was used to perform finite element analysis and simulation on the constructed fabric model.
The accuracy of the model is a prerequisite for the ideal results of finite element analysis. The similarity between the model and the fabric was measured by measuring the coordinates of 19 feature points. Firstly, the ABAQUS finite element analysis simulation results and experimental results of a single yarn were compared to analyze whether the material properties of the yarn are accurate. The comparison in Fig. 11 (b) proves the correctness of yarn material properties. Yarns are defined as a nonlinear elastic-plastic material, and material properties are determined by the tensile properties of the yarn, as shown in Tab. 2. Under the premise of national testing standards, finite element models with different seed sizes and friction coefficients were analyzed and simulated. It was found that when the seed size was 0.1 and the friction coefficient was 0.25, the difference rate between the simulated and experimental values was the smallest. In the finite element analysis, a seed size of 0.1 and a friction coefficient of 0.25 were selected to simulate longitudinal stretching and bursting of the fabric. By comparing the experimental values with the simulated values, as shown in Fig.12 (b) and (d), it is found that the maximum difference rate is 4.76%, the minimum difference rate is 0.29%, and the difference rates are all less than 5%. This indicates the feasibility of ABAQUS finite element analysis of fabrics’ mechanical properties.
After comparing the finite element analysis simulation and actual experimental results of five different fabrics, it has been proven that finite element analysis is not only applicable to engineering structural problems, but also to complex interwoven fabrics. The use of ABAQUS finite element analysis simulation can provide some auxiliary functions for enterprise sampling and weaving, which can further reduce the cost and time of enterprises.

Key words: finite element analysis, ABAQUS, mechanics, image processing, 3D modeling 

摘要： 针对用纱线进行纬平织物打样试织来预测织物力学性能和外观效果费时费力的问题，通过有限元分析对5种纬平针织物进行力学模拟测试实验。首先拍摄织物图像，选取19个特征点并获取坐标，用3次NURBS曲线对特征点进行拟合，构建微观单线圈中心曲线3D模型；根据该模型建立细观线圈单元模型，并通过衔接嵌套得到宏观织物模型。然后依次利用ABAQUS软件对单根纱线进行拉伸模拟实验，验证其在ABAQUS中赋予的材料属性正确性；对织物模型进行纵向拉伸和顶破实验，将材料属性在ABAQUS中赋予宏观织物模型，根据国家标准赋予分析步并提交分析，模拟结果与实验结果基本一致。

关键词: 有限元分析, ABAQUS, 力学, 图像处理, 3D建模