芳纶平纹织物单纱抽拔力学性能分析

为探究芳纶平纹织物抽拔力峰值和横向预张力受各因素影响机制和变化规律,通过在电子万能试验机上加装自主设计的快速对中夹具和力传感器,进行了以横向预张力、抽拔速度、试样规格和纱线类型为变量的单纱抽拔实验。结果表明：抽拔力和横向预张力在抽拔过程中发生同频率零相位差的震荡下降,抽拔力峰值与抽拔纱线的交织点数量、交织点处的张力和变形程度呈正比关系;当初始横向预张力从100 N增加至400 N时,抽拔力峰值从5.63 N增加至10.58 N,横向预张力的上升值降低,下降值增加;当织物纵向长度从30 mm递增至110 mm时,抽拔力峰值增加,峰值增幅降低;抽拔过程中,横向预张力的上升值和下降值都随着织物纵向长度的增加而增加;纱线织造密度越小,预紧后的卷曲程度越高,抽拔力峰值越大。     

基于可调张力装置的芳纶织物交织阻力研究

为更加真实地模拟芳纶织物在受到冲击时产生的交织阻力变化情况,通过构建一个半经验模型来预测对于不同规格、不同预加张力情况下纱线交织阻力的数值,并设计了可调预加张力的纱线抽拔实验用夹具,分别以织物的经向宽度、纬向宽度和预加张力为变量对纱线进行抽拔实验.实验结果表明:对织物施加横向预加张力与纱线抽拔时的交织阻力呈正相关,预加...     

平纹织物三维模型的建立和侵彻实验的数值模拟

提出平纹织物模型的函数,根据此函数建立了平纹织物的三维几何模型,并应用于数值模拟分析.所建立的几何模型考虑到了平纹织物真实的纱线间距、纱线的屈曲和纱线的截面形状.为建立此模型,需要测量平纹织物的3个参数:纱线间距、纱线厚度和纱线宽度.使用Creo Elements/ProR软件建立织物模型,模拟了子弹侵彻多层平纹织物的过程.实验对比表明,织物的真实变形情况与实验一致性较好.     

纱罗组织对芳纶织物交织阻力的影响

为增强芳纶机织物的纬纱交织阻力,将纱罗组织和平纹组织结合,以提升纬纱对横向抽拔作用的抵御能力。通过准静态纱线抽拔试验发现：在交织阻力位移曲线的退屈曲区内,纬纱的最大交织阻力和经纬纱屈曲交换程度密切相关;在黏滑区内,曲线呈现出一种震荡衰减趋势;纱线所受的交织阻力和被抽拔纱线根数几乎呈线性关系;同时抽拔2 根、3 根和4 根纱线的最大交织阻力对比于单纱抽拔的最大交织阻力的增幅分别是160% 、289% 和 389% ;纱罗组织的引入,有效增强了经纱对纬纱的握持性能。单纱抽拔试验结果表明,平纹/纱罗复合结构织物的纬纱所受最大交织阻力比平纹结构增加约20% 。多纱抽拔试验结果表明,交织阻力的最大增量约为65% 。     

线迹缝合对芳纶平纹织物抗侵彻性能的影响

为了增强纱线间约束,提升平纹织物的抗侵彻性能,通过线迹缝合技术对织物内部纱线进行缝合.抽拔试验结果表明:线迹缝合有效增强了经、纬纱之间的摩擦力,织物的最大抽拔力随着缝合线迹数量的增多而增大.此外,线迹缝合增加了平纹织物的硬挺度.侵彻试验结果发现:高速侵彻降低了织物的能量吸收能力;试样的能量吸收能力随着相邻2根缝合线迹间距的减小而增大,其中每根纱线缝合试样的能量吸收能力最大;试样的贯穿比能量吸收能力随着相邻2根缝合线迹间距的减小呈现先增大后减小的趋势,每隔1根纱线缝合试样的贯穿比吸能最大.缝合结构与平纹组织的复合工艺为软体防弹服内胆防护层的优化设计提供了可行性方案.     

基于大气辉光等离子体处理起绒针织面料的毛羽抽拔力

为研究大气辉光等离子体处理参数与涤棉起绒针织面料起绒面毛羽抽拔力的关系,采用不同等离子体处理电功率和处理时间分别对涤棉起绒针织面料起绒面进行处理,并测试各种参数条件下织物起绒面毛羽的抽拔力。结果表明:涤棉起绒针织面料起绒面的毛羽抽拔力与等离子体处理电功率和处理时间都具有一定的相关性;等离子体处理时间相同时,随着等离子体处理电功率增大,起绒面毛羽的抽拔力呈现先增大后减小的趋势;等离子体处理电功率相同时,延长等离子体处理时间,起绒面毛羽的抽拔力减小;在等离子体处理电功率为1 k W、处理时间为15 s时,织物起绒面的毛羽抽拔力最大,相比于未处理织物起绒面的毛羽抽拔力提高了114.1%。     

纺织基伤口清创材料的纤维抽拔力研究

为研究纺织基伤口清创材料的结构参数与纤维抽拔力的关系,选择6种不同绒密和底布纱线股数的试样。采用拆解法测定每种试样的单位质量、含绒量和底布质量;采用图像处理技术测定每种试样底布的未充满系数和孔隙率;测试每种试样的纤维抽拔力。结果表明:纺织基伤口清创材料的纤维抽拔力与绒密、底布纱线股数都有一定的相关性。底布纱线股数相同时,绒密越高则纤维抽拔力越大;绒密相同时,底布纱线股数越多则纤维抽拔力越大。     

剪切增稠液对不同结构芳纶织物防刺性能的影响

为实现防刺服的轻量化以提高可穿戴性,用剪切增稠液 (STF) 浸渍不同结构的芳纶织物制备柔性防刺材料,探究织物结构对STF/芳纶复合织物防刺性能的影响。借助流变仪、扫描电子显微镜、万能强力仪对STF的流变性及STF/芳纶复合织物的形貌、纱线抽拔力、准静态锥刺和刀刺性能进行表征。结果表明:STF的流变性能随着分散相质量分数的增加而明显增强;经STF浸渍后各织物的防刺性能都有明显提升,经纬密度较大的平纹织物表现出较优的抗锥和抗刀刺性能,其中最大抗锥刺和抗刀刺力分别为993.75 N和687.50 N;STF的剪切增稠作用能有效提高纤维间的摩擦从而限制纱线滑移,且随着织物交织点数增多,纱线间摩擦力增大;斜纹复合织物的刀刺性能提升最为明显,提升了387%,因为斜纹织物较长的浮长线能有效抵抗刀刃的切割作用。     

外套管状机织物抽拔过程的动态数值模拟

运用有限元分析法对管状机织物外套于管子时的抽拔过程进行了应力应变分布动态模拟和计算。结果表明基于所建立的管状机织物三维模型,在考虑了经纬纱本身结构非线性关系及管子与织物接触的非线性条件下,所得管状机织物的应力、应变分布及其最大值与常理性应力、应变分布基本一致,应力和应变的最大值发生点完全一致。同时管织物的接触长度对最大应力和应变值及其发生位置有明显影响,且接触长度增加会导致自锁。这为管织物抽拔自锁和破坏预估计提供了有效的预报方法。     

用变截面纱线模型模拟平纹织物的研究

为了逼真模拟平纹织物,采用变化尺寸大小的锯齿形椭圆截面的纱线模型,结合B样条曲面造型技术,利用Peirce机织物模型构造平纹织物的几何立体结构.根据VC程序运行结果来看,该纱线模型结合捻度结构用于模拟平纹织物的效果逼真.     

基于数字单元法的三维正交织物微观几何结构建模

为了反映织物内部纱线的空间构型和微观几何结构,针对在织物建模过程中,因忽略纤维间的相互作用而引起的纱线截面形状变化的问题,基于数字单元法理论,提出了一种计算纤维间摩擦力的方法。通过纱线纤维化离散,用数值模拟和仿真方法模拟三维正交织物成型过程,建立了5种精度递进的微观几何结构数值模型。5种模型中的每根纱线分别由4、7、12、19和37根数字纤维表征。研究结果表明:随着纱线纤维化离散程度的提高,仿真时间延长,织物厚度减小,纤维体积分数增大,节点平均作用力下降速度变缓,势能变小;当每根纱线由19根数字纤维组成时,所建织物的微观几何结构数值模型与真实织物样本在显微镜下的内部切片图像较为吻合。     

31—SOME ASPECTS OF THE MECHANISM OF SEAM SLIPPAGE IN WOVEN FABRICS

A theoretical analysis (subject to some assumptions) of the principles of seam slippage in woven fabrics is presented. It is shown that the amount of seam slippage, or fabric resistance to seam slippage, depends on such factors as yarn-to-yarn friction, yarn-to-sewing-thread friction, yarn flexural rigidity, and stitch and fabric geometry.     

Mathematical model to predict vertical wicking behaviour. Part II: flow through woven fabric

The aim of the paper is to develop a mathematical model to predict vertical wicking behaviour of woven fabric. The first part of this series (Part I) has dealt with the mathematical model for predicting vertical wicking through yarn. In this part a model has been proposed to predict vertical wicking of the woven fabric, based on the developed yarn model. In order to model the flow through woven fabric along with the vertical flow through liquid carrying threads, the horizontal flow through transverse threads has also been taken into account. A simplified fabric geometrical concept (inclined tube geometry) and Peirce geometry for plain woven fabric have been used to define the fabric structure. Warp and weft linear density, fabric sett and yarn crimp have been considered in the fabric modelling. The theoretical wicking values of the yarn and fabric made from that yarn have been compared. Experimental verification of the model has been carried out using polyester and polypropylene fabrics. The model is found to predict the wicking height with time through the yarns and fabrics with reasonable accuracy.     

产业用摩擦纺包芯纱性能研究

在DREFⅢ-摩擦纺机上生产涤纶短纤维包覆玻璃长丝作产业用包芯纱线,用于二维机织平纹织物及增强复合材料。通过摩擦纺包芯纱及其织物和复合材料与未经过包覆的玻璃长丝及其织物和复合材料的加工、拉伸张力、弯曲张力等性能的数据对比,来揭示摩擦纺包芯纱的性能特点。     

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.     

Finite element analysis of monofilament woven fabrics under uniaxial tension

Mechanical behavior of woven fabrics under tensile load is complex because their deformation could result from the combined effects of tension, compression, bending, and shear. In this study, the tensile behavior of woven fabrics is simulated using finite element method. The input parameters are the mechanical properties of constituent yarns obtained from tensile and friction coefficient tests and the geometry of woven fabric repeating unit. First, a 3D geometric model of the repeating unit based on Pierce’s model was built using computer-aided design tools. Then, finite element analysis which incorporates material properties, frictional contact, and periodic boundary conditions was implemented using ANSYS. A non-linear mechanical behavior was defined. Frictional contact algorithm for the cross-sectional zone of the repeating unit and periodic boundary conditions to the contour of the repeating unit was implemented. Numerical simulation data and experimental data were compared, which showed good agreement.     

Computer simulation of plain woven fabric appearance from yarn photographs

This article proposes a method for simulating plain woven fabric appearance based on photographs taken by still camera of actual yarns along their lengths. The survey mathematically models the transformation of yarns from a straight circular cylinder to a flattened and crimped form in the fabric structure. The simulation is performed by yarn images that are obtained by image processing techniques and resized according to mathematical models developed by means of the software prepared. Transforming circular yarn cross-section to elliptical one for simulating yarn flattening and modelling the crimped shape of yarn by an elastica curve are both convenient and realistic. The simulation of plain woven fabric can be performed by a method based on raster graphics. This article provides a model for yarn shape in fabric structure as well as a method for simulating plain woven fabric appearance. This method may be used in textile industry for design and quality control.     

机织物计算机模拟方法

分析现有的织物CAD软件在模拟素色织物时存在的不足,给出了纱线的数学模型,根据织物表面浮长线反光的原理,建立了织物浮长线上各点反光亮度计算的数学模型,该数学模型考虑了纱线屈曲、捻向、截面形状等因素对浮长线上各点反光亮度的影响。给出了根据上述数学模型计算并生成织物模拟效果图的方法,依据该方法在计算机上生成了素色织物模拟效果图。经过对上述数学模型的进一步优化,可使织物模拟效果图具有良好的真实感效果。     

基于一元二次函数的层联机织预制体细观结构表征

织物预制体结构参数之间的相互关系是高性能复合材料设计需要解决的关键问题。为建立层联机织预制体的细观几何关系,通过显微观察和结构分析提出基于一元二次函数的抛物线凸透镜形纬纱横截面、抛物线形经纱路径等假设,通过研究典型的多层平纹层间联锁结构层联机织预制体,建立预制体全厚度单胞模型,推导其细观结构参数的几何表达,获得纱线横截面变异系数、预制体厚度和纤维体积含量的计算方法,从而实现预制体结构的细观设计。通过实测值和理论预测值的对比,验证了该细观模型的有效性和合理性,并确定了层联机织平纹预制体的纱线填充因子取值区间为0.73~0.87。