Fabric objective measurement and drape

This issue of Textile Progress reviews the origins of fabric objective measurement through its research and development phases to its current use in research and industry. It then examines, in greater detail, the use of fabric objective measurement (FOM) methods for the measurement and prediction of fabric drape. Such prediction has become increasingly important in recent times, due to the push from the fashion industry for accurate three-dimensional (3-D) simulation and animation of apparel in its various forms, to allow fashion designers to visually prototype their garment creations without the need for the tedious and time-consuming steps involved in real-garment prototyping. The demand for accurate 3-D simulation and animation is occurring in the face of an ever-increasing variety of fabric types, which means that drape measurement methods must become more sensitive and more widely applicable than has been the case to date. The authors, in the light of this review and their own research experiences with fabric drape, offer the view that the measurements taken by existing methods of FOM and drape are unlikely to provide the accuracy and wide applicability required for realistic on-screen evaluation of apparel, not least because in a garment, fabric is neither draped nor supported horizontally in the way that the fabric is configured in the test methods.     

基于支持向量机的织物悬垂性能评估分析

针对织物悬垂性评估中存在非线性建模困难及评估精度不高等问题,结合织物悬垂性参数数据的特点,基于Mercer核函数的性质,构建Mercer核函数的织物悬垂性评估模型。通过实验,认为其评估精度有了相应的提高,说明基于Mercer核函数的织物悬垂性评估模型是可行的。同时,通过改变参数值进行实验,结果表明这些参数的取值不同对评估结果有影响,且不同参数对评估结果影响的程度也不同,这对基于支持向量机的织物悬垂性评估过程有重要的指导作用。     

Investigation of fabric drape-flexural rigidity relation: modified fabric drape coefficient

Abstract

The drape is an important characteristic of textile fabrics. Several studies have been concerned with the mechanism of fabric drapability and the methods of its measurements. In this study, a new drape coefficient ‘DCM’, evaluating the shape of the fabric drape, is defined in terms of the drape projection, the shape and the number of the folds and the drape angle. The drape of fabric samples with different weft densities and weaves structures was tested. The new formula to express the drape coefficient, taking into consideration the fabric flexural rigidity, was developed. The analysis of the experimental results indicated that the modified drape coefficient is highly correlated with fabric flexure rigidity and other fabric structure properties than the other known formulas.     

织物悬垂性图像测试方法

为了解决图像法织物悬垂性测试中存在的图像采集和边缘轮廓信息提取困难等问题,从图像采集、悬垂图像轮廓分析及悬垂指标提取3个方面探讨织物悬垂性的图像测试方法。设计了新的图像采集方法,确保采集到高清晰度、高对比度的织物悬垂图像;编写了包含边缘检测、二值化、邻域点边界轮廓跟踪等算法程序的织物悬垂性测试软件,应用该软件可提取出悬垂图像边缘轮廓信息;根据织物悬垂图像轮廓信息,经半径确定、轮廓展开和指标计算等步骤,可测得织物悬垂性的多个特征值,如悬垂系数、波数、波峰幅值均匀度、波峰夹角均匀度、最大波峰幅值、最大波峰夹角等。     

涤纶织物性能指标与悬垂形态关系

为利用织物力学性能指标对织物悬垂性能进行预测,通过实验得到织物力学性能指标和基本结构参数,借助多元线性回归分析,得到悬垂性能的系列预测方程,并通过计算机模拟对结果进行验证.结果表明,织物悬垂形态与织物力学性能指标和结构参数密切相关,尤其是织物45.方向的剪切刚度、交织阻力、厚度、纬向密度等指标对织物悬垂形态的影响较大,...     

织物悬垂测试系统中织物边缘的识别

由于织物花纹式样的多样性,传统的图像分割算法常常无法准确地识别出织物边缘轮廓。根据织物悬垂图像的边缘轮廓特点,提出采用基于梯度向量流场(GVF)的动态轮廓模型(Snake模型)来识别织物的边缘轮廓。采用贪心算法实现了Snake边缘检测模型,分别用该模型和基于边缘梯度扫描的算法识别5种典型印花织物悬垂边缘,并将2种算法得到的边缘轮廓进行了比较。实验结果表明,该边缘检测模型能准确地识别多种传统图像分割算法所无法准确识别甚至无法识别的特殊织物的边缘轮廓。     

基于三维悬垂模型和织物面密度的织物匹配

为能够根据织物的悬垂形态快速准确地匹配到与给定织物综合性能相近的织物样本,利用自主搭建的悬垂织物三维扫描装置获取了悬垂织物的三维点云数据。将三维点云封装为三角形网络后,利用局部线性嵌入的方法对悬垂织物三角形网格重采样,使不同的悬垂织物三维模型具有相同的顶点数目和三角形拓扑结构;然后基于重采样三角形网格提出了2种织物匹配方法,即基于传统悬垂指标和织物面密度的织物匹配以及基于曲率统计直方图和织物面密度的织物匹配;最后计算了织物力学特征的相似度,以此相似度为基准对织物匹配结果进行评价。结果表明:基于悬垂指标和织物面密度的织物匹配准确率为86.91%;基于曲率统计直方图和织物面密度的织物匹配准确率为93.79%。     

织物静态悬垂系数试验时间的确定

为了科学地确定织物静态悬垂系数的试验时间,选用自行设计的利用图像技术测试悬垂性能指标的XDP-1型织物悬垂仪,其试样放置方法为试样托盘平稳上升,织物试样自重下垂,能有效地测试1块处于静止状态的织物试样在1个时间序列下的多个静态悬垂系数值。通过对织物静态悬垂系数随测试时间变化曲线的分析,认为试验时间设定为固定时间的规定是不合理的,并提出采用最小试验时间来测量织物静态悬垂系数,这样可提高测量结果的合理性与重现性。     

Prediction of fabric drape using the FAST system

In this study, we investigated the relationship between the fabric drape coefficient from the drape meter and mechanical properties tested on the fabric assurance by simple testing system (FAST). Different kinds of woven fabrics with two kinds of weave (plain and twill) were tested. Three regression models are proposed for each type of weave and for all fabrics using the multiple linear regressions. The regression results were analyzed in terms of correlation coefficients, T and p-values. A neural model is proposed using the neural networks and it is compared to the regression one.     

风格仪转速与织物悬垂性的关系研究

以16块织物为研究对象,用KES-FB风格测试系统测试了织物的拉伸性能、剪切性能和弯曲性能,运用YG(L)811-DN织物动态悬垂风格仪测试了5个转速下各织物的悬垂系数和波纹数,通过相关分析和方差分析研究了转速对织物悬垂系数与波纹数的影响,结论如下:随转速的增加,织物悬垂系数基本呈线性增加;试样结构参数与织物悬垂系数增加率之间的相关性不明显;而经向弯曲刚度及经、纬向剪切刚度与悬垂系数增加率有显著负相关关系,转速对波纹数没有显著影响。     

基于三维人体形态的织物立体悬垂测试方法与表征

针对传统织物悬垂性能测试法的固有缺陷,以人体三维形态为基准,提出了一种测试自然悬垂状态下织物立体悬垂性能的新方法,研制了织物三维立体悬垂仪,并依此原理设计和制作了简易模型测量装置。提取织物的波纹数、悬垂系数、平均弯曲指数、弯曲变异指数等指标,对织物立体投影曲线进行CAD模拟分析研究结果发现：与传统伞式悬垂测试法相比,新方法所得悬垂系数与织物的悬垂性能成正相关,2种方法所测波纹数接近,相关性高达0.9,表明三维立体悬垂性能测试方法可更逼真地反映织物的真实悬垂性能与形态。由此建立的织物悬垂性能指标体系可更好地反映织物的造型能力。     

织物悬垂性影响因素分析

织物面料制成服装或窗帘等家居用品后，其力学性能构成悬垂性。文章利用实验测试的方法对织物的结构参数和机械性能进行研究，分析织物结构参数和机械性能与悬垂性之间的关系。结果表明，织物的断裂伸长、纬向弯曲刚度和活络率与悬垂性能之间存在密切的关系，而织物厚度和质量对悬垂性的影响不显著。     

Drape simulation of woven fabrics using a mass-spring system

Abstract

In this paper, a mass-spring system is used to predict the draping behavior of woven fabrics. The material properties important to fabric draping are measured from the Kawabata system and the experimental data are incorporated into the simulation to calculate internal forces, based on which the draping behavior of particular types of woven fabrics is dynamically demonstrated. The hysteresis behavior in mechanical tests of a certain fabric is displayed virtually by calculating the internal restoration forces of the system. To evaluate the validity of the method, both the virtual drape measurement and the real drape measurement are performed to compare the same drape attributes derived from the two measurements. The simulation results and the experimental data are in good agreement.     

波形褶在服装设计中的应用

服装上采用波形褶是近年来较为流行的一种设计手法。探讨波形褶在不同面料和不同类型服装上的应用,通过对波形褶的处理增加了服装的艺术效果,丰富了现代服装设计的手法。     

A novel approach for simulation of curling behavior of knitted fabric based on mass spring model

Edge curling is a unique property of knitted fabrics which affects on fashion such as using upper and side curling in cloth design. The purpose of this research is to present a new method to simulate drape behavior of knitted fabric considering difference between single and double jersey knitted fabrics. To this point, at first the bending and torsion moments that applied on the fabric edges and caused curling in single knitted fabric are determined. Also it demonstrated that these moments will be neutralized in double knitted and as the results, leads to a non-curling structure. Then, using the mass spring model, curling shape in fabric wale and course directions are simulated. To show efficiency of the proposed model, real 3D shape of single knitted fabric is compared with experimental results. Also, using the proposed model, the drape behaviors of single and double jersey knitted fabrics hanging from two fixed corners with different properties are simulated and then extend to simulation of skirt. Results of simulation are compared with 3D shapes of actual drape behavior in fabric samples which are achieved by depth camera. The simulated results show good agreement with 3D shapes of actual fabrics.     

泡泡袖袖山褶皱凸起量的影响因素

探讨面料性能和袖山剪开量对泡泡袖造型效果的影响。采用5种性能迥异的面料,分别测量出其厚度、悬垂性、面密度、硬挺度等物理性能。结构设计中,在原型袖袖山处加放不同的参数,绘制泡泡袖样板;以袖山褶皱凸起量为主要因素,测量相关数据,并分析得出结论：当袖山剪开量偏小和中等时,面料的厚度和面密度对褶皱凸起量影响最大;当袖山剪开量偏大时,面料悬垂率越大,褶皱凸起量越小;面料性能一定时,褶皱凸起量的大小随着袖山剪开量的增大而增大。     

织物形态风格评价的主因子分析法

在织物形态风格评价上通过主因子分析方法的应用，将评价织物悬垂美感的多个特征参数指标简化为少数几个主因子，同时用因子得分图将织物驾分类，为合理评价织物外观形态美观，满足服装选料要求提供了一种新方法 。     

Evaluating drape shape in woven fabrics

A search of the scientific literature for the period 1950–2013 retrieved 36 different drape indicators. Despite the large number of indicators currently available, the drape ratio (%DR) continues to be the most widely used, even though it has proved inadequate to explain drape shape. In order to assess their actual performance, the 36 currently existing drape indicators were determined in a total of 37 commercial drapery, woolmaking, shirtmaking and lining woven fabrics spanning a wide range of composition, aerial weight and weave type using a digital Cusick drape meter. A correlation analysis between indicators, and subsequent suppression of duplicity and collinearity, revealed that seven were mutually correlated. A principal component analysis of the results revealed an underlying structure consisting of three common factors which allowed the indicators to be classified into three different groups according to drape intensity (a), severity (b) and shape symmetry and variability (c). Cluster analysis was additionally used to examine the results in graphical form and exposed three clusters coinciding with the three factors of the underlying structure. A criterion for distinguishing fabrics with an identical drape ratio in terms of drape shape based on sequential application of four of the seven initially selected indicators was developed and experimentally validated.     

织物静态悬垂性测试过程中图像采集问题的研究

分别采用织物动态悬垂性风格仪和基于织物静态悬垂性风格仪自行组装的DIY仪器,对织物的静态悬垂性进行测试,并对测试过程中图像采集方式的选择和俯视死角问题进行分析。研究结果表明:当纯色织物的颜色与背景颜色反差较大或花色织物的图案花色与背景颜色相差较大时,宜采用上打光直接采集图像;当测试织物为半透明织物时,宜采用下打光直接采集图像;上打光顺光采集图像过程中出现俯视死角导致的图像采集不清晰问题,可通过增大支持盘半径或增大相机与试样间距的方法解决。