倒Ω法测试织物弯曲性及悬垂性

织物悬垂性和弯曲性的测试是纺织品检测的重要内容,目前这2种性能是分开进行的。针对此现状,以13块常见织物为研究对象,分别测试其弯曲性和悬垂性指标——抗弯刚度和悬垂系数,然后用自行设计的倒Ω法进行测试,并利用图像处理软件提取了水滴高宽比和下垂纵横比等特征参数。经过相关分析得出以下结论:作为尝试提出的倒Ω法可同时用来检测织物弯曲性和悬垂性,所提取的指标与抗弯刚度和悬垂系数具有较好的相关性,相关系数由大到小依次是下垂纵横比、水滴高宽比和水滴面积;利用下垂纵横比与抗弯刚度及悬垂系数的关系式,可以预测织物的弯曲性及悬垂性。     

可视化织物弯曲性测试方法

针对纺织面料弯曲性测试需要多次裁样、费时等问题,提出1次可得到多组结果且快速简便的太阳花法测试方法。通过选择经纬2个方向的试样,裁剪5个宽度为2 cm、长度为6 cm的单条测试样,搭建测试装置并选取特征指标：展开面积、展开周长、展开长度和下垂高度。将太阳花法所得指标与斜面法测试的抗弯长度与抗弯刚度进行对比分析。结果表明：4个新指标均与斜面法中的抗弯长度和抗弯刚度具有较好的相关性,证明本文方法具有良好的可行性。该方法既可将织物正反面弯曲性差异及弯曲稳定性结果可视化,还可提高测试效率,节省检测时间。     

用蝴蝶结法测试毛织物弯曲性

针对现有织物弯曲性测试需要用多块试样才能得到多个测试结果的现状,提出一种既简便又节约面料的预测毛织物弯曲性的方法蝴蝶结法。详细阐述了用蝴蝶结法测试织物弯曲性的实施步骤及采用的表征参数:蝴蝶结面积、宽度、高度和角度。以18块毛织物为研究对象,用新方法与传统方法进行对比测试分析。结果表明:新方法中的4个参数与毛织物的抗弯刚度都具有较好的相关性,且越硬挺的毛织物形成的蝴蝶结角度、宽度和面积越大,高度越小,其中蝴蝶结面积与抗弯刚度的相关性最高;用蝴蝶结法建立的蝴蝶结面积与织物抗弯刚度的关系式可预测毛织物的抗弯刚度。     

织物多方向硬挺度测试方法研究

现有的织物硬挺度检测方法每次只能得到织物某一个方向的数据。针对这种情况,提出一种简便的、可同时测试织物多方向硬挺度的方法,并给出了具体的检测步骤及评价指标:硬挺度系数、凹陷深度、平均翘起高度。将常见试样经凹陷法所得的这3项指标与斜面法中织物5个方向的平均弯曲长度及平均抗弯刚度进行了对比分析,得出这3项指标与平均弯曲长度及平均抗弯刚度相关性从大到小依次是硬挺度系数、凹陷深度和平均翘起高度,且这3者与平均弯曲长度及抗弯刚度都具有高度线性相关关系。这说明笔者提出的织物多方向硬挺度的测试方法有一定的可行性,值得进一步深入研究。     

悬挂穿孔法测试织物弯曲悬垂性

为探究同时测试织物弯曲性和悬垂性的方法,文章以24块常见机织物为研究对象,分别用斜面悬臂梁法和圆台法测试抗弯刚度和悬垂系数,之后自行设计悬挂穿孔法测试装置并进行实验,提取得到四项特征指标:侧轮廓面积、底轮廓面积、载荷峰差值、峰值膨胀角。相关分析和回归分析的结果表明:悬挂穿孔法可以同时测量织物弯曲性和悬垂性,且四项特征指标都与抗弯刚度、悬垂系数具有高度相关性,得到的两个回归方程可用于预测织物整体的抗弯刚度和悬垂系数。悬挂穿孔法只用一块试样就能综合表达织物整体的弯曲悬垂性,既节约测试时间,又节省测试面料。     

织物悬垂性能的各向差异性研究

为研究织物悬垂性能的各向差异性，对传统的伞式测量法进行改进。选取15种常见织物，采用XDP-1织物悬垂仪对织物0°、90°、45°和135°4个方向的悬垂性进行测试并获取悬垂图像；基于所得图像提出最大展宽、投影面积和悬垂系数3个新指标；最后分析织物各向悬垂性与弯曲长度和抗弯刚度的关系。结果发现：这3个新指标与弯曲长度和抗弯刚度均具有较好的相关性；织物硬挺的方向易形成波峰，柔软的方向易形成波谷，织物某方向的悬垂性越好，越易弯曲，该方向的抗弯能力越小。这表明通过一块圆形试样的悬垂投影可以预估织物某方向的弯曲性能，利用改进的伞式法可以测量织物悬垂性能的各向差异性。     

缝制条件下织物的弯曲和悬垂性能

本文首先调查分析不同类型缝份部位整体弯曲性能的变化,然后着重研究在不同接缝位置、不同缝型和不同缝份宽度条件下有缝织物的悬垂性能变化及其原因。结果显示：缝份部位的抗弯长度和抗弯刚度与原织物相比有明显增加;有缝织物的悬垂系数、平均半径、硬挺系数等指标均大于无缝织物;一般缝份宽度增加,悬垂系数有稍微增大趋势;接缝的位置对悬垂性的影响与织物经纬向性能有关;抗弯长度大的缝型一般比抗弯长度小的缝型对悬垂系数影响大;试样边缘缝份会导致圆周方向的抗弯性能提高,从而使悬垂系数增加。该研究将对缝制后面料及服装造型评价及模拟具有一定的实践指导意义。     

织物弯曲性与悬垂性测试新方法

织物弯曲性和悬垂性是影响服装外观的重要性能,其测试目前是分开进行的,文章旨在寻找可将其合二为一的方法。首先测试25块织物的弯曲长度和悬垂系数,然后用自行设计的M形测试法提取新的指标,并将其与弯曲长度和悬垂系数进行对比。研究表明:新方法中的指标均与弯曲长度具有较好的相关性,相关性由大到小依次是柔悬系数、横向投影宽度和纵向投影高度,且柔悬系数与悬垂系数也具有较好的相关性。新方法可同时测试织物弯曲性和悬垂性,即利用1块试样可得到2组数据,且可表达织物在任意一个方向上的悬垂性,尤其适合风衣、休闲裤等有方向性要求的织物。     

织物多方向弯曲性能测试新方法

针对现有的织物弯曲性能测试方法利用一块试样只能得到一个方向结果的问题,探索了织物多方向弯曲性能测试方法。首先,选取20块常见织物,用传统的斜面法测试织物0°、90°、45°和135°的弯曲长度;然后,用自行设计的多方向弯曲性能测试方法测试织物4个方向(0°、90°、45°和135°)的投影长度和投影面积;最后,用相关分析研究了投影长度和投影面积与弯曲长度的关系。结果表明:投影长度和投影面积均与弯曲长度具有较好的相关性,相关系数约为0.95;本文方法可利用一块试样同时测试织物0°、90°、45°和135°的弯曲性能,且每个方向有2组结果,比传统的斜面法更高效,还可将织物弯曲各向异性可视化,在一个图像上体现某一方向的弯曲稳定性。     

数字图像技术在织物悬垂性上的应用及影响悬垂性的因素分析

利用现代化的数字图像技术来检测织物的静态悬垂性,具有传统伞式法不可比拟的优势,可以大大提高效率,同时获得多项悬垂性指标;初步研究了织物伸出长度、弯曲刚度、剪切刚度对静态悬垂系数的影响.     

织物马鞍状弯曲试验研究

为更好地表征织物在实际弯曲状态下的力学特性,使用自制的织物马鞍状弯曲测试装置,分别选用两种不同厚度和面密度的纸、塑料薄膜与织物为试样,在马鞍状弯曲情况下采用单因素分析法探讨了织物长度、宽度和加载速度等测试条件对织物受力负荷-位移的影响,并确定出织物马鞍状弯曲测试参数。结果表明当评价指标为抗弯刚性时,在下端距离16mm,试样宽度50mm,加载速度50mm/min条件下,采用马鞍状弯曲测试方法测定织物弯曲性能与采用斜面法测定性能相比,具有较好的一致性。     

利用十字交叉法测试织物弯曲悬垂性

为探索可同时测试织物弯曲性和悬垂性的方法,以20块常见织物为研究对象,分别用斜面法和圆台法测试弯曲长度和悬垂系数,然后用自行设计的十字交叉法进行测试,并提取了横向下垂距离、纵向下垂距离和弯曲悬垂系数。研究结果表明：十字交叉法既可用来检测织物弯曲性,也可检测织物悬垂性,且3个指标与斜面法的弯曲长度都具有较好的相关性,其相关系数由大到小依次是弯曲悬垂系数、横向下垂距离、纵向下垂距离;弯曲悬垂系数与圆台法侧得的悬垂系数也具有高度相关性;十字交叉法将传统的织物弯曲性和悬垂性的测试合二为一,既简化了操作步骤,又节约了时间。     

丝织物抗弯刚度仪的原理和研制

丝织物抗弯刚度仪是采用高精度测力传感器和位移传感器，并据纺织总会“织物弯曲试验方法”的原理研制而成的。该机设计合理，测试精度同，操作简易，使用方便能检测各种真丝与仿真丝织物的弯曲刚性。文章着重介绍了电路设计与工作原理。     

Analysis of bending properties of worsted wool yarns and fabrics based on quasi-three-point bending

Abstract

The bending behavior of worsted wool yarns and fabrics plays a crucial role in handling and performance of end-use textiles. Hence, the fabric/yarn bending properties were studied based on a quasi-three-point bending model by means of the theoretical modeling and the corresponding measuring method. By means of the formula and the measured curves, the curve of bending rigidity and the curvature of a fabric or a yarn can be calculated so as to characterize the bending behavior more precisely than in the previous work. All the experiments on the fabric/yarn bending rigidity have been conducted for both the worsted wool fabrics and the corresponding yarns procured from the fabrics, with the same apparatus bending evaluation system of fabric and yarn, which was developed independently. The measured results of bending rigidity and curvature curve show good correlation with the bending moment and the curvature relationship of the theoretical modeling, and the comparisons of bending rigidity among KES-FB2 (Kawabata Evaluation System for Fabrics-2 pure bending tester), FAST-2 (Fabric Assurance by Simple Testing-2 bending meter), and the independently developed apparatus show that the three systems exhibist reasonably high correlations. It is confirmed that the new apparatus and the theoretical model are both viable and precious. Meanwhile, the theoretical relationship between the yarns and the fabrics has also been discussed, and the theoretical analysis of the bending behavior between the yarns and the fabrics is helpful in selecting a better theoretical model of the fabric-to-yarn bending rigidity ratio.     

Theoretical and experimental analysis of bending rigidity of plain and twill woven fabrics

The study of bending behavior of woven fabrics is an important issue in textile scientific researches and its industrial applications. Different behavior of fabrics such as drape, comfort, and handling can be understood by this study. Bending rigidity of fabric depends on several factors such as weave geometry, bending rigidity of yarn, and yarn density. In this study, estimation of bending rigidity of woven fabric with different twill and plain structures, have been carried out using energy method. Generally, the woven fabric structure is divided into three different section lengths i.e. rigid, semi-rigid, and flexible sections. Thereafter, bi-component and tri-component models for predicting bending behavior of plain and twill woven fabric have been presented. Then, bending properties of fabric based on Shirley apparatus as well as weight per area as a physical property were measured. Good agreement between measured and predicted values, validated our theoretical models for obtaining bending rigidity, except considerable differences observed between experimental and predicted values using bi-component model of plain fabric. Therefore, using assumptions in calculation of the ratio of rigid section length to flexible section length (R₁), the modified model of plain fabric has been proposed.     

利用织物实际弯曲形态测试其弯曲性质的算法

介绍了织物弯曲理论和测试方法的研究现状,提出了一种利用织物在自重作用下的实际弯曲形态间接测试织物弯曲性质的测试方法。详细叙述了该方法的测试原理,在此基础上利用数学多项式回归和微积分方法对实际弯曲形态曲线上的信息进行计算处理,提出了织物在自重作用下的弯矩与曲率、弯曲刚度与曲率关系的算法。利用此方法对织物进行测试,取得了很好的结果,与KES方法测试得到的弯曲刚度值对比,获得了很好的相关性验证。     

A Fixed-Supported beam modelling for measuring fabric rigidity using small deflection equations

Bending rigidity of fabric is an important property attracting much attention in the fields of measuring and modelling. In this work, a Fixed-Supported elastic beam is proposed. The fabric strip is fixed at one end and simply supported at the other end. In this way, the errors due to twisting or curling of the free end of fabric can be omitted. The fabric is deflected under its own uniformly distributed weight. The experiments were carried out on different types of fabrics and different beam lengths were tested. Using a digital camera and image processing method, the geometric shape of the bent fabric was recorded and maximum deflection of the fabrics was obtained. According to the theory, small deflection equation holds as long as there is a linear relation between maximum deflection and fourth power of beam length. To investigate this, the plots of maximum deflection vs. forth power of beam length were obtained. The results reveal that the variation of maximum deflection vs. fourth power of beam length indicates a good linear trend with high linear regression coefficient. It can be concluded that Fixed-Supported beam in the case of small deflection can be used to calculate the bending rigidity of fabric with an acceptable accuracy. From the slope of the fitted line, the bending rigidity of the fabric was calculated.     

对丝织物弯曲刚性测试方法及丝织物弯曲刚性的研究

通过对丝织物弯曲刚性测试方法的多次试验与分析，确定了初始压力、试样的形状及最大位移几个技术参数，从而为有效地利用测试手段，客观评判丝织物的服用性能提供了依据。文中还对各类丝织物的弯曲刚性进行了测试与分析。     

织物的弯曲性能

用线性粘弹理论对织物在小弯曲变形情况下的弯曲性能作了分析。假定织物的弯曲行为是粘弹性的,具有内摩擦约束,内摩擦弯矩与弯曲曲率成正比。织物流变模型由标准线性固体模型和一个摩擦元件并联组成。通过分析曲率周期性变化时的弯曲行为,建立了弯曲性能与模型参数之间的关系。利用实验所得到的模型参数对表征织物弯曲性能的指标进行计算,理论计算与实验结果相符。