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.     

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。     

双模型互证法在评判休闲西裤外观保持性中的运用

利用KES织物风格仪,LFY-1织物折皱回复性测定仪,YG811织物悬垂性测定仪获得了织物的基本力学性能指标、悬垂系数及折皱回复角;通过实验运用主观评价法获得了休闲西裤外观保持性的主观数据;然后运用灰色理论获得了表征休闲西裤外观保持性的织物基本力学性能指标。在此基础上,以休闲西裤外观保持性主观评价值为依据,运用模糊综合评判与近优灰元模型来评判休闲西裤外观保持性,得出的2种模型评判均有效,模型之间起到了互证的作用。     

织物悬垂系数与FAST力学性能的灰色关联分析

对目前描述织物外观形态应用最广泛的悬垂系数与FAST力学性能的关系进行了灰色关联分析，结果表明，悬垂系数和FAST力学性能具有较高的关联度。     

Development of Apparels from Silk Waste and Pineapple Leaf Fiber

The degummed mulberry silk waste and eri silk waste were blended with degummed and bleached pineapple leaf fibers (PALF) at fiber stage in different proportions, and spun into yarn in a jute spinning system. The 90-tex blended yarn thus developed was analyzed for different physico-mechanical properties. Properties of fabric developed in a traditional handloom using 2/40-s cotton as warp and blended yarn as weft were also analyzed. The quality parameters, viz., tensile property, crease recovery, fabric cover, stiffness, drape, and thickness of the developed fabric, met essential apparel requirements. A comparative subjective evaluation of the fabric quality, viz., aesthetic appearance, luster, and texture, was made with the help of a group of people from different age, educational, and occupational background to examine its marketability; all respondents felt that appearance of PALF with silk waste was excellent. Texture and luster were found to be from medium to moderate. About 95% of respondents felt that fabric was crispy.     

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.     

生物机械湿整理对大麻/棉混纺针织物服用性能的影响

对大麻／棉混纺针织物进行生物机械湿整理，结果表明，织物的折痕回复性、悬垂性、透气性和表面性能得到了改善，顶破强力显著下降，而透湿性和导热性无显著变化。     

Tencel纤维及其织物的性能研究

介绍了Tencel纤维的性能 ,并通过对纯Tencel织物、Tencel混纺织物及粘胶织物性能的测试分析 ,证明了Tencel织物具有优良的服用性能     

数码织物动态悬垂风格仪的研究

使用变频技术改变织物旋转速度，使用高速数码相机拍下织物的悬垂形态，通过数码相机与计算机连接进行悬垂图形的收集和处理，得出一组有关织物悬垂风格的悬垂系数、活泼率、美感系数、硬挺度系数等参数，可将织物的静、动态悬垂图形和波纹曲线用彩色打印机打印出来。     

Introducing and optimizing a novel mesh for simulating knitted fabric

In this paper, a mass spring system is developed to simulate the draping behavior of knitted fabric. A new type of mesh based on loop structure, which is called Loop mesh, is introduced. The effective properties on fabric drape are measured using the Fast system, and the experimental data are incorporated into the mass spring model to simulate the draping behavior of knitted fabrics. 3D shape of real drape behavior of fabric samples is achieved using depth camera. Then in order to reduce error value between simulated and real results, distances between mass points in the Loop mesh are optimized using the Imperialistic Competitive Algorithm (ICA). In order to investigate validity and accuracy of the Loop mesh, drape behavior of knitted fabrics falling over a square table are also simulated using common meshes. It can be found that the Loop mesh produced a closest drape shape to the real fabric drape than other mesh models. Finally, fabrics drape is simulated in other situations and compared with its real result to validate the proposed model. Results show that the optimized model is able to simulate the drape behavior of knitted fabric with error value of 4.29 percent.     

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 Prediction by Means of Finite-element Analysis

The draping behaviour of fabric treated as an orthotropic shell membrane is predicted by using a geometric non-linear finite-element method, and the results are compared with actual behaviour. A drape tester employing photovoltaic cells was designed and constructed to determine the drape coefficient of fabric specimens of 10-in. diameter. The warp- and weft-direction tensile moduli of these samples were determined by using a Kawahata Tensile and Shear Tester, and literature values of Poisson's ratio were obtained. With this approach, excellent agreement between experimental and predicted drape coefficients resulted. For a 100% cotton plain-weave fabric, a drape coefficient of 68.4% was experimentally determined as compared with a predicted value of 71.0%.     

Investigation of Seam Pucker in Lightweight Synthetic Fabrics as an Aesthetic Property Part I: A Cognitive Model for the Measurement of Seam Pucker

Seam pucker is an area which is now receiving particular attention especially with the development of microfibre fabrics which are inherently prone to deformations during garment manufacture. Although fabric properties can be related to seam pucker, the aesthetic judgement is still left to subjective assessment which is based upon ranking the stitched fabric samples by judges having compared them with photographic ‘standards’. The shortcomings of this procedure are obvious; judges do not always agree, they need to be trained, the procedure is time consuming and non standardised. This paper reports upon the development of a new measuring procedure which is based on the use of a computer and a camera, ie computer ‘vision’. This procedure is objective and is focused on the aesthetic property of the seam assembly, by ‘modelling’ the cognitive process involved in seam pucker assessment The results are organised in two parts: Part I reports on the development of a cognitive ‘model’ for the measurement of seam pucker and Part II on the model implementation using the computer ‘vision’ system.     

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。     

织物动态悬垂性的模拟研究

对YG811L织物静态悬垂性测试仪进行改装,采用风车来模拟织物在动态时的悬垂形态,并用投影法获取动态风车在硫酸纸上的投影图像;进而对图像进行分析,以获得一种研究织物动态悬垂性能的方法。     

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。     

纤维组分与针织组织对针织物悬垂性的影响

悬垂性对针织物的外观及内在性能都有重要影响,而不同纤维组分纱线和不同组织的针织物悬垂性能也有很大区别。选用相同支数的纯羊毛纱、纯腈纶纱、羊毛/腈纶70/30纱3种典型的针织纱和纬平针组织、1+1罗纹组织、2+2罗纹组织3种常规的针织组织,利用正交试验法分析纤维组分与针织组织对针织物悬垂性能的影响。研究结果表明:混纺比例不同的纱线品种对针织物的悬垂性有一定影响,针织组织对针织物悬垂性的影响特别显著,因此在设计针织服装时应该有针对性地选用不同组分的针织纱和针织组织,以实现理想效果。     

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.     

精纺毛织物悬垂性研究

选取了19种精纺毛织物,运用KES- FB织物风格测试仪测试织物拉伸剪切性能、弯曲性能和表面性能,运用动态悬垂风格仪测试织物悬垂性指标,且进行相关分析和回归分析.结果表明:精纺毛织物的静态悬垂系数是一个很重要的悬垂性指标,与大多数悬垂性指标都呈高度正相关关系;且织物静态悬垂系数越大,则硬挺度系数也越高,织物美感系数就越高.通过回归分析得出了织物剪切性、弯曲性及拉伸线性度与静态悬垂系数之间的方程式,此方程可以用来预测精纺毛织物静态悬垂系数.