不同纱线张力下的三维正交织物微观几何结构建模

从织物组织入手,建立纱线截面形状为圆形的三维正交织物拓扑结构。在此基础上,采用数字单元法理论在纱线首尾两端施加周期性边界和恒定张力,并通过纱线纤维化离散方法,将纱线分为既定数量的数字纤维,进而改变其截面形状和空间构型,实现织物织造成型过程的动态仿真。研究结果表明,施加较大的经纬纱张力及较小的接结纱张力,所得数值模型的经纱与纬纱厚度均匀且能保持伸直状态,接结纱截面变化情况与真实正交织物相符。当经纬纱线张力为0.2 N、接结纱张力为0.01 N时,织物数值模型厚度与实验值仅差9.55%,其微观几何结构与织物样本显微图像吻合度较高,验证了数字单元法理论在织物亚纱线尺度建模的有效性。     

2.5D浅交弯联机织复合材料压缩性能研究

根据纤维单丝的分布假设建立了纤维束几何模型,通过观察2.5维（2.5D）浅交弯联织物成型后内部浸渍纤维束的截面和走向建立了织物结构几何模型。为了分析的便捷性,对纤维束几何模型和织物结构几何模型分别选取了可重复代表性单元。然后通过利用自定义程序（UMAT）定义了每个单元的材料属性和方向;嵌入周期性边界条件保证了单元边界面的应力连续和位移连续;基于改进的损伤准则和刚度折减模型进行了渐进损伤分析;通过实验研究和有限元分析深入了解了该材料的初始弹性模量和最终压缩强度、损伤机制等,并发现经向压缩并未明显表现出脆性破坏。     

三维五向编织物细观结构分析及数值计算

以三维五向织物细观结构为研究对象,通过建立单元体几何模型,推导出了编织工艺参数和织物结构参数之间的数学计算关系,并用板块编织试验对计算结果进行了验证,所得结果与理论分析结果吻合较好。证实了所建模型的正确性,为三维五向织物结构的设计、计算和应用提供了理论基础。     

三维绞织机织物几何建模与仿真

根据纱罗组织结构特点提出三维绞织机织物,为满足织物结构构建的精准性,利用织物层数、纬纱列数、经纬纱个数等参数进行表征;根据机织造工艺情况与织物结构参数,对经纱绞织规律研究提出经纱系统规律参数方程,使用Matlab构建经纱曲线获取型值点,通过三次B样条曲线控制点建立经纱系统模型,提出纬纱系统结构参数方程,完成织物几何模型;利用Solidworks构建织物仿真模型。     

基于UG二次开发的三维正交机织物模型构建

为了快速准确地构建整体正交机织物的结构,本文针对传统方法难以清楚地表达正交机织物的交织结构这一问题,在分析整体正交组织结构特征的基础上,提出采用织物层数(经纱层数+纬纱层数)、经纱列数、纬纱列数、接结纱根数以及接结的方式等五个参数来表征整体正交组织;设定了理想正交组织中经纱、纬纱和接结纱的形态,采用巨元体法建立了纱线截面尺寸的计算方法;利用UG/Open GRIP提供的开发环境建立纱线的模型,并编制程序构建整体正交机织物的立体结构,实现了通过输入必要的参数即可完成对整体正交组织进行快速准确建模的功能;所建模型不仅能清楚表征织物的结构,还可以计算织物纤维体积含量和织物厚度等参数。     

基于最小势能原理的2.5D机织物的结构模型

以纬纱为直线、经纱为曲线,建立了2.5D机织物几何结构模型。根据弯矩方程和J.W.S.Hearle原理得到经纱总势能与附加张力、未知的织物结构参数的关系式。当2.5D机织物的尺寸在附加张力作用下趋于稳定时,织物中的纱线系统应满足最小势能原理。根据最小势能原理,将确定经纱曲线方程中结构参数的问题转化为求泛函数极值的问题,利用织物结构的几何和力学特点,再把泛函数的极值问题转化为函数极值来处理,然后利用拉格朗日乘数法求解,得到包含2.5D机织物结构参数与力学指标的微分方程组及约束方程组,更为直接地表达结构参数与力学性能之间的关系,为计算机动态模拟织物的各项力学性能指标提供了一个更为可靠的依据。     

三维机织弯交复合材料细观结构研究及弹性性能分析

本文对三维机织弯交复合材料的细观几何结构进行了深入的研究，采用了椭圆形纤维束截面假设，详细研究经纱纤维束在织物表面与内部的不同。建立了一种新的三维机织弯交复合材料力学分析模型，并在此模型的基础上对其弹性常数进行了预测，讨论了结构参数和几何参数对三维机织弯交复合材料弹性性能的影响。通过实验值和理论预测值的对比，表明了分析方法的正确性。     

展纱织物细观几何模型

在合理的假设基础上,通过建立的展纱织物增强结构二维几何结构模型,预测展纱织物内纤维束屈曲状态,建立展纱织物复合材料的纤维体积分数的理论公式,分析纤维束屈曲率与纤维体积含量之间的关系。理论计算结果与实测值的比较,表明所提出的细观几何模型是合理的。     

不同填充率下FDM 3D打印预制件建模及力学性能分析

以拉伸、压缩、弯曲、扭转4种受载情况下的熔融沉积型三维（FDM 3D）打印预制件为研究对象，以填充率、填充单元结构类型为分析参数，通过确定3D打印预制件填充率的影响因素，建立了填充率与格子形填充单元几何参数的通用解析式，据此构建不同填充率下3D打印预制件的三维几何模型；然后对不同受载类型3D打印预制件进行有限元仿真分析，明确填充率对不同载荷工况下3D打印预制件力学特性的影响规律。仿真和实验结果表明，填充率对3D打印预制件所受拉伸应力、压缩应力、弯曲应力均有较大影响，而扭转情况下影响较小，据此进一步确定了一定受载情况下3D打印预制件的较优填充率；基于本文提出的不同填充率下预制件三维模型建立方法，可有效实现对预制件的力学性能仿真分析，对减少产品试验验证次数、降低研发成本具有积极作用。     

多层机织物增强复合材料的拉伸与剪切性能研究

本文采用单向板组合模型，建立了多层机织物增强复合材料的本构关系，讨论了织物结构设计参数对复合材料拉伸与剪切性能的影响，在此基础上，借助于纺织手段，设计加工了三种不同层数，不同接结组织，不同纬纱是号数以及不同接结以比例的多层机织物，选用不饱和聚酯树脂，成型了相应的复合材料试样，并测试了试样的经向拉伸模量，并测试结果与理论计算进行了比较。     

Drape behavior of 3D woven glass‐epoxy composites

This article deals with the drapability of 3D woven glass fabrics for composite applications. The study focuses on forming a 3D fabric over the mold, the result is a preform, which generally is then injected with a polymer matrix by so called Liquid Composite Molding (LCM) technique. When draping pre–impregnated composites, the fabric is embedded in the epoxy resin as matrix material. Various drape models for dry and pre‐impregnated fabrics have been proposed in the work. Solidworks and ANSYS are the software used for modeling and simulation of 3D woven fabric composites. Given the linear density (tex) and density of E‐glass fiber, the radius of the yarn was calculated. So far the cross section of yarn is assumed to be perfectly circular in shape, keeping the perimeter of yarn constant the circular cross section was deformed into a race track shape which is a much more practical and realistic shape of a yarn cross section. After calculating all the required dimensions, all the three 3D woven structures namely angle interlock, warp interlock and orthogonal were developed in solidworks. All the parameters like total number of warp and weft yarn per unit distance and thickness of the fabric were kept constant in all three structures. The analysis is based on first principles and the parameters of yarn and fabric construction. Results obtained through simulation are reported. These are validated with experimental composite samples. The model used to predict drapability of 3D woven glass‐epoxy composite gives good results. Orthogonal structure proves to be the best as far as resistance to deformation is concerned. However, if a relatively more flexible and formable prepreg is desired, it is advisable to use angle interlock or warp interlock structures. Warp interlock 3D structure proves most beneficial for draping on a mold. POLYM. COMPOS., 37:472–480, 2016. © 2014 Society of Plastics Engineers     

Color pattern recognition for yarn‐dyed fabrics

In the process of designing and analyzing the yarn‐dyed fabric, the yarn color pattern has an important effect on the appearance of the fabric. An automatic color pattern recognition method for yarn‐dyed fabric is proposed in this study. The proposed method uses the fabric images obtained from a high‐resolution digital camera image acquisition system. The local statistical texture features are used for yarn texture segmentation. The yarn color classification problem is then formulated in a research framework of multiregion fuzzy segmentation, which can be added auxiliary variables and solved efficiently by the fast dual projection algorithm. The color values of the yarn crossing points are calculated by the yarn color classification results. The locations of the yarn crossing points are detected by a lightness gradient projection method. Different kinds of fabrics are tested in the experiments. Experiments on 14 actual fabrics show that the approach proposed in this study is effective for classifying yarn color and extracting the yarn color pattern in yarn‐dyed fabric.     

Thermomechanical characteristics of basalt hybrid and nonhybrid woven fabric–reinforced epoxy composites

In this study, experimental investigations are performed to check the thermal and mechanical behavior of woven Basalt/PP and Basalt/Jute fiber hybrid and nonhybrid woven fabrics and their composite laminates with epoxy. Three types of weaves are used for both hybrid and nonhybrid structures. Tensile testing of all the woven fabrics is performed. The thermal properties of the fabrics, that is, thermal resistance, diffusivity, and thermal conductivity, etc. are also studied vis‐a‐vis physiological behavior. Results are discussed in terms of fiber composition, woven geometry, and the fiber : resin ratio. Fabricated composite samples are subjected to dynamic mechanical analysis (DMA) and thermo gravimetric analysis (TGA). The thermophysiological properties are also studied in reference to yarn and fabric structure. POLYM. COMPOS., 37:2982–2994, 2016. © 2015 Society of Plastics Engineers     

Automatic detection of layout of color yarns of yarn‐dyed fabric. Part 3: Double‐system‐Mélange color fabrics

Automat layout detection of color yarns is necessary for weaving and producing processes of yarn‐dyed fabrics. This study presents a novel approach to inspect the layout of color yarns of double‐system‐mélange color fabrics automatically, which is Part III of the series of studies to develop a computer vision‐based system for automatic inspection of color yarn layout for yarn‐dyed fabrics. The inspection of single‐system‐mélange color fabrics has been realized in Part I of the series of studies. Integrating the projection‐based region segmentation method proposed in Part I and the FCM‐based stepwise classification method proposed in Part II, the proposed approach is composed of three steps: (1) fabric region segmentation, (2) fabric region selection, and (3) layout of color yarns recognition. In the first step, the fabric regions are segmented by the projection‐based region segmentation method. In the second step, the reasonable fabric regions are selected by analyzing their color histograms and comparing their weft color's frequency. In the third step, the layout of color yarn is recognized by the FCM‐based stepwise classification method, and the precise layouts of color warps and wefts are produced. The experimental analysis proved that the proposed method can recognize the layout of color yarns of double‐system‐mélange color fabrics correctly by testing four different color fabrics and three pieces of same yarn‐dyed fabrics. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 250–260, 2017     

涤纶浸胶帘子布(帆布)的技术经济分析

本文首先介绍了国内外涤纶帘子线(布)发展情况、主要生产厂家及规模、各种骨架材料应用范围及其性能比较及涤纶帘子线技术指标等。第二介绍了涤纶树脂增粘、纺丝制帘子线及其生产工艺流程。第三介绍了涤纶帘子布厂的建厂规模、单位产品的投资数及成本、涤纶工业丝产品单位成本的测算和比较、涤纶浸胶帘子布单位成本的测算和比较。第四介绍了各种化纤工业丝比价、涤纶工业丝和民用丝比价、涤纶工业丝与帘子布的比价及浸胶帘子布与轮胎比值、最低售价的测算等。最后提出核定价格的几个原则及其建议价格。     

聚乳酸纤维抗菌织物

选用14.6 tex的聚乳酸纱线作为原料,用ASS3000单纱机对纱线进行上浆,SV111型剑杆自动织样机织造聚乳酸纤维平纹织物,采用Na2CO3碱液退浆法对织物进行退浆,H2O2对织物进行漂白,经热定形处理后,使用SCJ-939固着剂和CYK-302无机载银抗菌剂对织物进行抗菌整理,开发出聚乳酸纤维抗菌织物。对抗菌整理前后的聚乳酸织物的服用性能和抗菌性能进行了测试分析,研究证明:开发的聚乳酸纤维抗菌织物具有良好的服用性能和抗菌性能。     

An efficient method for solid‐colour and multicolour region segmentation in real yarn‐dyed fabric images

This paper presents an efficient approach to solid‐colour and multicolour region segmentation in real yarn‐dyed fabric images. The approach is based on a novel model describing the spectral response of a multispectral imaging system to yarn‐dyed fabrics. The model indicates that solid‐colour regions cannot be distinguished from multicolour regions in terms of reflectance, tristimulus, or CIELAB values owing to a geometric term representing the influence of fabric surface condition on measured colours. The geometric term makes it difficult to determine the segmentation thresholds of CIEXYZ and CIELAB colour histograms. However, solid‐colour and multicolour regions can be detected in CIExyY space because chromaticity coordinates are impervious to the geometric term. The CIExyY histograms of a solid‐colour region accord with one Gaussian distribution, but those of a multicolour region accord with a combination of two Gaussian distributions. The CIEXYZ, CIELAB, and CIExyY colour distributions of both solid‐colour and multicolour yarn‐dyed fabrics were analysed in detail in simulation and real experiments. Experimental results show that solid‐colour yarn‐dyed regions can be distinguished from multicolour yarn‐dyed fabric regions by the shapes of CIExyY histograms, but cannot be distinguished by the shapes of CIEXYZ or CIELAB histograms.     

SUPERCOOL织物与纯棉织物吸水透气性能比较

将SUPERCOOL短纤纱织成纬平针组织,并对织物进行染整处理,测试其基本结构特征参数,用毛细效应法和比利时UCB法来比较SUPERCOOL织物的吸水性能,测试分析其透气性能,并与同纤度纯棉针织物相比较。结果表明:SUPERCOOL织物具有优异的吸水及透气性能。     

Measuring linear density of threads in single‐system‐mélange color fabrics with FCM algorithm

According to the color yarns in the fabric, the fabrics can be divided into three categories: solid color fabrics, single‐system‐mélange color fabrics, and double‐system‐mélange color fabrics. The density of solid fabrics can be inspected with gray‐projection method or Fourier analysis method. But the methods cannot be applied to yarn‐dyed fabrics directly. A method for detecting the density of single‐system‐mélange color fabrics will be discussed in this article. By analyzing the pattern and color characters of single‐system‐mélange color fabrics, fuzzy C‐means algorithm is proposed to classify the colors in the fabric image based on CIELAB color space first. With the color segmentation results, the fabric can be divided into different blocks. The yarns can be located in different blocks with different average gray‐levels, and then the number of yarns can be counted in each block. The linear density of threads can be obtained by counting the yarns in a unit length finally. The experiment proved that the algorithm proposed in this study can inspect the density of single‐system‐mélange color fabric successfully. © 2012 Wiley Periodicals, Inc. Col Res Appl, 38, 456–462, 2013     

天然抗菌植物靛蓝在牛仔纱线染色中的应用

对植物靛蓝连续染色牛仔纱线进行了实验研究。染色纱线织成的面料耐水洗色牢度、耐汗渍色牢度、耐干摩擦色牢度及耐唾液色牢度都在4级及以上,该面料及其经多种洗水风格处理后的服装对金黄色葡萄球菌的抑菌率在80%以上,对大肠杆菌的抑菌率在78%以上,具有很好的抗菌性能。