应用弹簧-质点模型的双贾卡提花织物形变仿真

为改善双贾卡提花经编织物的结构形变仿真效果,在分析双贾卡织物线圈结构形变影响因素的基础上,建立了成圈型、压纱型和衬纬型线圈几何结构模型;在传统的弹簧质点模型基础上进行改进,取线圈根部作为质点,线圈之间的延展线为弹簧,根据双贾卡提花特点,针对压纱贾卡与衬纬贾卡设定虚拟质点,建立双套弹簧系统;根据牛顿第二定律和显式中点法,计算质点在二维平面的运动形态,从而确定线圈的偏移方向和偏移量;利用建立的弹簧-质点模型与力学分析模型在VC++语言下实现了双贾卡提花经编织物的二维静态仿真,通过实际样例与对应仿真效果对比,验证仿真方法。     

Application of discriminant analysis to parameters describing the drape for two types of woven fabrics

A total of 33 commercial drapery and lining fabrics were used to determine the drape indicators drape ratio and R-factor. The slope of a plot of one indicator against the other was found not to afford complete characterization of drape shape for fabrics of different commercial use. In this work, further six parameters describing the drape, proposed by the authors to discriminate drape shapes were also calculated. Discriminant analysis of the data revealed that a linear combination of various parameters allowed two types of woven fabrics (viz. drapery and linen) to be distinguished. The discriminant function used accurately classified 75.76% of the fabrics studied.     

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。     

Investigation of mechanical behavior of woven/knitted hybrid composites

The objective of this research is to develop the woven/knitted hybrid composites for improved in plane as well as out of plane mechanical properties. Two different type of structures and two different materials were used in this study. Firstly, the woven and knitted fabrics were developed with glass and Kevlar yarn. Secondly, the laminated composite samples were fabricated with different stacking sequence of fabric plies. The epoxy resin was used as matrix. The cured samples were characterized for impact, tensile and dynamic mechanical properties. The behavior of composite materials was then analyzed with percentages of different fiber and fabric types. The samples with higher percentages of knitted reinforcement gave better impact strength but failed to provide better tensile properties. Moreover, the samples with higher percentages of woven structure and glass materials gives better modulus values.     

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.     

Modelling crease recovery behaviour of woven fabrics

Crease recovery behaviour is an important property of fabrics for apparel applications. A theoretical model is developed in which the fabric is represented by an elastic element and a frictional element. The frictional restraint is assumed to be proportional to the square root of the curvature of the fabric during deformation. An energy method is applied to the study of crease recovery behaviour of the fabric. Equations of crease recovery work and crease recovery force as a function of curvature are derived. Two basic parameters are needed to characterise the fabric in the crease recovery model: the bending rigidity and bending hysteresis of the fabric; both are readily measured in a pure bending test. Good agreement is observed between experimental data and theoretical predictions for wool/polyester blended and worsted fabrics.     

服装二维裁片虚拟模拟技术

在三维服装虚拟缝合及试衣过程中,服装2-D裁片虚拟模拟是关键技术之一。应用服装CAD软件绘制服装纸样并存储成DXF格式,通过DXF文件接口程序将纸样载入系统。采用正则栅格法对裁片进行四边形剖分,连接四边形对角线完成对2-D裁片的三角网格化。以三角形顶点为质点、三角形边为弹簧,构建裁片质点-弹簧模型,通过模型受力分析、数值求解完成对2-D裁片的虚拟模拟。以男士背心为例,通过裁片网格剖分实验验证正则栅格法的有效性;同时完成对背心裁片自然下落于桌面和背心虚拟缝合效果模拟。     

织物组织结构对机织物力学性能的影响

纺织品组织结构对织物的外观和应用性能具有普遍的适用性,织物的最终用途在很大程度上取决于所用的材料及其物理特性.因此,织物的结构参数直接决定了织物的性能.研究了不同组织结构对织物力学性能(包括拉伸性能、撕裂性能和耐磨性能)的影响,主要探讨了平纹、斜纹和方平组织对织物力学性能的影响.     

Textile electrodes of jacquard woven fabrics for biosignal measurement

In the last few years, textile electrodes have become an interesting topic for physiological monitoring, steadily developing to be applied in innovative wearable sensing systems. The structure of textile electrodes can be fabricated by weaving, knitting, or embroidering conductive yarn and is now commercially available. The upgraded textile electrode is used in biosignal sensing and was designed in the form of a jacquard woven structure to measure the ECG. In the case of knit fabric, which has piezo‐resistive properties, the textile electrodes were developed by using the fabric’s flexible strain gauges in a bio‐monitoring system. However, the piezo‐resistive sensing fabrics have some shortcomings such as low dynamic range, poor repeatability, and performance deterioration after washing or repeated folding. Woven fabric, which is cloth woven in the warp and weft directions, has less strain properties and can be constructed more uniformly than knit fabric. Therefore, due to their more consistent woven structure, jacquard woven fabrics made with conductive yarn can be manufactured evenly on a large scale and consistently maintain their properties. The woven structure of jacquard electrodes consists of a double‐faced weave and is woven with a silver covering yarn in the weft direction. The proposed textile electrodes were composed of two groups made up of warps with either the unremoved 100% warps or the half‐removed 50% warps of jacquard woven electrodes that were convex or flat and were either with or without conductive paste. The ECG measurements for the textile electrodes were repeated three times in resting conditions. The convex jacquard electrodes of the half‐removed 50% warps with the conductive paste resulted in the most significant SNR improvement (33.67 dB). The purpose of this paper was to investigate a method to design jacquard woven electrodes uniformly on a large scale and to apply it feasibly to ECG measurement.     

织物折皱回复性能的研究

把毛织物看成是具有内摩擦约束的弹性条,利用能量分析的方法对毛织物在折皱回复时的回复力与变形的关系进行了分析,通过;简单的模型及公式将织物在回复过程中的重要性质表征出来,理论与实测结果基本吻合。     

石墨烯黏胶纤维机织物的功能改性研究

制备同规格的普通黏胶纤维机织物、石墨烯黏胶纤维机织物及不同不锈钢丝质量分数的石墨烯黏胶纤维/不锈钢丝机织物,对比它们的导电、防电磁辐射、防紫外线、抗静电、力学(拉伸、弯曲、耐磨)及透气等性能。结果表明:普通黏胶纤维经石墨烯改进后,所制成的石墨烯黏胶纤维机织物的导电、防电磁辐射、防紫外线、抗静电、力学(拉伸、弯曲、耐磨)等性能都有所改善,其中防紫外线与耐磨性能提高显著,透气性能下降明显;石墨烯黏胶纤维/不锈钢丝机织物的导电、防电磁辐射、防紫外线和抗静电、经向拉伸断裂强力、纬向抗弯刚度、透气性能都优于石墨烯黏胶纤维机织物,纬向拉伸断裂强力、经纬向拉伸断裂伸长率、经向抗弯刚度及耐磨性能不及石墨烯黏胶纤维机织物;随着不锈钢丝质量分数在7.0%~20.0%范围内的增加,石墨烯黏胶纤维/不锈钢丝机织物的导电、防紫外线、抗静电、经向拉伸断裂强力、纬向抗弯刚度及透气性能增强,纬向拉伸断裂强力、经纬向拉伸断裂伸长率、经向抗弯刚度、耐磨性能减小,不锈钢丝质量分数变化对防电磁辐射性能影响较小。当不锈钢丝质量分数为7.0%时,石墨烯黏胶纤维/不锈钢丝机织物的综合性能最佳。     

Enhancing accuracy of drape simulation. Part I: Investigation of drape variability via 3D scanning

The objective of this two part paper is to present a method of enhancing accuracy of fabric drape simulation using commercially available software. In Part I, we report results of an investigation of drape variability for a set of fabrics having varied mechanical properties, an essential step in defining accuracy for drape simulation. Results illustrate that fabric drape behaviour is highly variable and thus provide no single drape configuration to target with simulation. Development of a revolutionary method for capturing drape of actual fabrics and measuring that drape in a virtual three-dimensional (3D) environment is also presented. The method allows identical drape measurement processes to be implemented for actual and simulated fabrics and provides opportunity for use of additional measures to assess fabric drape in three dimensions. The accomplishments presented in this paper are utilized to demonstrate, in Part II, development of a relationship that enhances realism of particle model simulations generated using the commercial drape simulation software.     

织物折皱回复角的计算

利用标准固体单元和滑块并联组成的模型,在织物摩擦约束力偶与其弯曲曲率成正比的假设下,对织物的弯曲和折皱回复进行了分析,并用纯弯曲实验得到的数据计算出织物的模型参数,从而计算出织物在不同时刻的回复角,平纹织物的理论预期与实测结果符合较好。     

有限单元法在织物悬垂仿真中的应用研究

以梁单元为模型，运用有限元法研究织物的悬垂性问题．建立了织物的模型进行理论分析，并进行了悬垂度仿真。仿真结果验证了模型 与方法的有效性，而且计算速度较快．     

织物镜面反射光分布曲线的模拟计算

提出了一个较为接近实际的织物结构模型。结合织物组织结构因素对织物的镜面反射光分布曲线进行了模拟计算,从理论上证明了织物组织、经纬密度、屈曲波高、纱线长短轴之比、纤维折射率以及入射角等因素都对镜面反射光的分布具有较大影响。     

Optimization of bending and shear rigidities of woven fabrics using desirability function

Abstract

Banding and shear properties influence the drape and handle characteristics of woven fabrics. As bending and shear rigidities of woven fabrics generally have high degree of association, it is difficult to design a woven fabric having low bending rigidity and high shear rigidity or vice versa. This paper deals with the optimization of bending and shear rigidities of woven fabrics using the desirability function approach. Low stress mechanical properties such as bending rigidity and shear rigidity have been combined to represent ‘the overall desirability’ which is varying from 0 to 1. The overall desirability has been maximized against the target values of shear and bending rigidities. It was possible to attain overall desirability of 0.684 resulting from individual desirability of 0.662 and 0.707 for banding and shear rigidities, respectively. Experimental validation confirms that the applied method can be effectively used to optimize the woven fabric mechanical properties at low stress region.     

基于虚拟仿真系统的翻驳领结构的数字化修正

翻驳领由翻领和驳领两部分组成.翻驳领的造型变化需要遵循其内在规律,旨在表现程式之美.影响翻驳领造型的因素很多,在结构上翻折松量值、倒伏量、驳口线斜率、领座高度和翻领宽度的差值等均影响外观质量.引入CLO3D数字化设计系统对西装驳领结构的整体美观度、驳领平整度、翻领圆顺度、翻领内口贴合度和翻领外口贴合度进行评价,并结合客...     

拉细羊毛织物结构与风格研究

文章以拉细羊毛(OPTIM)纤维纯纺及混纺织物为对象,应用扫描电子显微镜(SEM)观察拉细羊毛织物表观形态结构,测试了织物风格、动态悬垂性和光泽.研究结果表明:拉细羊毛织物拉伸功及压缩功回复率高;平均摩擦因数小,摩擦因数的平均差不匀率大,织物滑爽;织物压缩平均厚度值小,表面厚度较小,织物的光泽正反射光强和漫反射光强较大,对比光泽度较大,呈现良好的光泽及平滑性.     

Investigation of automated geometry modeling process of woven fabrics based on the yarn structures

Fabric structure has a significant effect on the thermal protective performance of fabrics. Before studying the thermal performance of textiles by numerical methods, it is essential to create geometric models of textile structures. Common fabrics, such as plain weave, 2/1 twill, 3/3 twill, 5/3 satin, and double layer fabric, were modeled using TexGen software. To obtain the input data for geometry simulation of fabrics, geometric measurements were studied. Methods of modeling fabric geometries according to their yarn path function and cross-sectional shapes were introduced. The appearances of the geometric models were very close to the structures of the real fabrics when compared to their light microscopic images. The fabric models were well used to simulate the heat transfer properties of glass fiber fabrics.     

测配色影像系统在羊绒及羊毛织物生产中的应用

文章主要介绍了DATACOLOR测配色及影像传输系统在羊绒针织、机织系列产品的颜色检测控制和管理过程中的应用.在实践过程中,应用测配色系统建立了颜色电子文档,实现了颜色的规范化、数字化管理,应用影像传输系统实现了与客户的颜色数据传递确认及无色样打样,提高了反应速度,并使产品色差得到了有效的控制.