棉/不锈钢长丝机织物的电磁屏蔽及折皱回复性能

为研究组织结构与磨损对织物屏蔽性能的影响,以及不锈钢长丝对织物折皱回复性的影响,使用自制的棉/不锈钢长丝包芯纱织制了3种不同组织的机织物,测试了织物在0.3~1 500 MHz频段上的电磁屏蔽性能,并使用平磨仪对各织物分别摩擦60、120、180、240 及300次后,测试了织物磨损后的电磁屏蔽性能;同时,采用视频序列法测试了织物的动态折皱回复角。结果表明：织物组织结构对电磁屏蔽性能有一定影响,平纹组织结构紧密,屏蔽效果好;经过若干次磨损后,织物的电磁屏蔽性能先小幅升高后逐渐降低;相同磨损条件下,试样耐磨性越好,屏蔽效能的降低幅度越小;由于不锈钢长丝的加入使织物的折皱回复性降低,可以采用浮长更长的组织改善织物起皱现象。     

关于机织物结构计算机辅助设计的分析

计算机技术在飞速发展的过程中,融入社会的各行各业,使工作效率和工作质量得到进一步提升,纺织行业便是"受益者"之一。对机织物结构计算机辅助设计进行研究,提出平纹织物和非平纹织物两项织物结构数学建模,总结出计算机图形理论、经纬组织单位模型两项计算机模拟原理,最后用模式范例对其进行解释,希望能为纺织工作者提供帮助。     

玻璃纤维织物的自动几何建模研究

织物的组织结构与其性能有很大的关系。通过设计并织造了四种不同组织(二维方平组织、3/1斜纹组织、双层斜纹组织,以及三维角连锁组织)、不同厚度的玻璃纤维织物,并对它们的几何形态进行模拟。结果表明,根据纱线的物理结构参数和织物的实际照片创建织物几何模型可行,且模型能够反映纱线的空间结构。     

基于真实感图像生成原理的机织物外观模拟

总结了目前机织物CAD系统在机织物外观模拟方面存在的问题,提出了利用真实感图像生成的方法模拟机织物外观的新思路,并在充分考虑光照对模拟机织物外观效果的基础上给出了利用计算机模拟机织物真实感外观的原理、过程和结果。     

含PET/PTT聚酯弹性长丝的毛织物弹性控制因素

研究了在织物紧度相同的情况下,纱线捻度、纤维细度、织造方式、染整方式等因素对含PET/PTT聚酯弹性纤维的毛混纺织物弹性的影响.过大的长丝捻度会降低织物的变形和弹性回复性能;长丝细度增加,使得织物在小外力下不容易变形,回复性能较好.将长丝和毛涤纱并线作为纬纱和将1根长丝、1根毛涤纱间隔作为纬纱的方式织造,织物弹性变形能力没有差异.经过拉幅定形的织物弹性变形能力小于经过松弛定形处理的织物.原色着色丝和白丝均能很好的实现织物弹性,但染色丝织物的变形能力要好于原液丝和白丝织物.     

织物折皱回复性能建模研究

基于纺织材料的弹性回复性能及织物的内摩擦作用,研究织物在较小折皱力作用下的折皱弯曲与回复性能,通过简单的模型及公式表征织物回复过程中的重要性质,分析毛及毛涤织物在折皱回复过程中回复力与折皱弯曲形变的关系。利用KES-FB3压缩仪设计折皱弯曲测试试验,用所得数据计算模型参数,能较好地反映出织物折皱回复规律,理论计算值与实测值吻合程度较好。     

飞轮缠绕用圆环织物的设计

为提高复合材料飞轮的径向强度,设计了径向也存在纱线的圆环形织物,它是按照飞轮层状展开得到的形状,经纱沿圆环的圆周方向,纬纱沿半径方向。分析圆环形织物在织造过程中经纬纱间的剪切变形,从织口到织物被织机的卷取成形辊握持,剪切变形角逐渐增大。剪切变形的存在,使机上圆环形织物的大小半径比设计值要小,而经纱密度变大。推导出织物机上尺寸与设计尺寸之间的关系,并可用于圆环织物的设计。实际制织了一种碳纤维圆环形织物,下机后经相反方向的剪切变形,得到了与设计相一致的结构。     

A novel hybrid genetic and imperialist competitive algorithm for structure extraction of woven fabric images

The woven fabric is a flexible object and to specify its parameters, applying inflexible and ordinary methods of image processing ever have considerable errors. In this regards, proposing an adaptable method to fabric image properties is concentrated to detect the yarns position. In this research, a flexible algorithm is proposed containing two stages: first, the inexact ranges of fabric parameters are determined by preprocessing colored fabric images using wavelet transform and clustering methods. Then, the hybrid genetic and imperialist competitive algorithm is applied to optimize the obtained ranges and detect the yarns position. To achieve better results, the parameters of the hybrid ICA–GA are calibrated using the Taguchi method. Results indicate that in this new method, the error value of detecting structural fabric parameters has considerably decreased to 5% as compared with common gray-scale projection method. The proposed method is capable of detecting the exact yarns position in colored fabric images with uneven color intensity and low-density weave with mean precision value of 96.2%. In the fabric images with high density weaves, the mean precision value is more than 94.72%.     

机织物结构相模型剖析和修正

针对机织物结构相传统模型未能敏感反映不同组织结构状态差异的问题,剖析了模型的约束条件和不足,建立了能够有效反映组织信息的结构相模型。提出了相对屈曲波高概念用于表征不同织纹组织中纱线的弯曲程度,为结构相模型的修正提供了理论参考。研究结果表明：结构相改进模型随屈曲波高的增加而增加,但呈非线性关系;对于不同织纹组织,形成等支持面的结构相是不固定的（0 结构相除外）,相同屈曲波高对应着不同的结构相,三原组织的结构相值之间存在平纹＜ 斜纹＜ 缎纹;在低结构相区域,结构相与屈曲波高可看成非线性关系,在高结构相区域改进模型与传统模型有统一性。     

粘盖涤导湿机织面料的设计

导湿干爽面料是一种新型功能性面料,能使人体的汗液导出并保持皮肤的干爽。根据导湿机织面料的设计原理,对粘盖涤导湿机织面料的设计进行了探讨。     

Experimental and macro finite element modeling studies on conformability behavior of woven nylon 66 composite reinforcement

Abstract

In this study, 3D hemispherical forming experiments are conducted to analyze the conformability behavior of nylon 66 plain woven reinforcements with different weft densities. To make insight into the forming process, a macro finite element model is also proposed for 3D forming of a specific woven reinforcement by using the defined ‘Fabric’ material. The results show that the proposed FEM modelling is highly correlated with experimental findings in terms of forming energy values with small and insignificant errors values, which confirm well model validity. It shows that the nylon 66 composite woven reinforcement with a lower weft density exhibits a lower forming energy (toughness) and hence a higher conformability over a hemispherical surface. On the other hand, modeling outputs clearly indicate that more wrinkling intensity appear for woven reinforcement with a higher weft density.     

Ideal stitch model for interlock-knitted fabric

This analysis is presented as two- and three-dimensional ideal models for an interlock structure. These are developed from the ideal model loop for plain structure that was suggested in our pervious research works (Jeddi et al., Int. J. Eng., 12, 39–40, 1999; Semnani et al., J. Text. Inst., 94(1), 204–213, 2003). These models are based on the classic curve of the strophoid equation as the loop shape of face and back loops and improved by adopting an elastica configuration. Then, a quadratic equation is taken as the linking portion between face and back loops. Thereafter, the nondimensional constant of stitch density values (U _s ) obtained from the theoretical models was compared with the experimental values, which were obtained from measurements of cotton interlock fabrics. It is observed that there is a good agreement between the theoretical predicted and experimental U _s values.     

二维机织复合材料力学分析中的周期性边界条件研究

为了精确地进行二维机织复合材料力学性能的数值分析,需建立单胞模型的准确边界条件。基于周期边界条件理论,提出了简便通用的二维机织复合材料周期边界方程,并给出了周期边界条件下各弹性常数在有限元分析中的求解方法;为验证周期边界条件的正确性,建立了９ 个单胞构成的九宫格结构,取中央单胞作为参考单胞,对不同边界条件下独立单胞的变形和应力分布与参考单胞进行对比。研究结果表明：即使在单向拉伸载荷下,单胞各个边界面也不保持平面状态,而是出现凹凸翘曲变形,即存在边界周期性;通过边界周期性条件,可正确地获得二维机织织物的工程弹性常数。     

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.     

纬编针织物线圈建模与变形三维模拟

为使纬编针织物具有更真实的力学效果和体积感,在改进的弹簧-质点模型的基础上对线圈进行结构建模。同时采用插值算法,在相邻型值点间插入两个新的型值点,用NURBS样条曲线连接线圈型值点,解决了NURBS不能穿过所有型值点的问题。为模拟股线的捻度,以此样条曲线为几何中心,用四根圆柱围绕,通过对相邻型值点的空间坐标计算三个相对欧拉角,对圆柱进行相应的旋转变换。测量了真实线圈的形变量,分析出线圈形变量与质点位移量的关系来模拟线圈变形。用velocity-Verlet数值积分方法求解力学方程,计算各质点位移。借助于Microsoft Visual Studio 2010集成开发工具和OpenGL三维绘图函数库,在计算机上实现了纬编织物的三维建模和变形仿真。     

织物图像增强矩阵特征模型的建立

针对目前缺乏有效显现织物特征的成熟模型,使织物疵点识别效果不佳的现状,提出一种新的织物图像特征模型,即增强矩阵特征模型.该特征模型以图像的灰度值为基础,引入一种新的增强矩阵.该矩阵由根据织物图像梯度变化生成的矩阵算子组成,可对像素灰度值进行变换计算以放大或缩小图像局部特征,使图像的特征显现更加层次分明.通过采用MatL...     

基于Web的经编无缝织物设计模型

随着互联网时代的到来,将CAD技术与互联网技术相结合已是必然趋势。为了实现基于互联网的经编无缝织物交互设计,在研究经编无缝织物工艺原理的基础上,建立了无缝织物的设计模型,并详细介绍了无缝织物花型绘制、组织覆盖、基本组织定义及边部的贾卡设计模型和交互原理。利用Canvas元素完成贾卡图形的绘制及鼠标交互功能。最后介绍经编无缝织物的设计流程,并验证模型的准确性。基于互联网的经编无缝织物设计方法具有可随时修改设计、随时查看设计产品、操作方便快捷、免安装、免维护等明显优势。     

毛织物质量的计算机辅助模糊评价

根据模糊数学理论建立了适合计算机处理的毛织物质量评价模糊矩阵,在此基础上说明了评价的计算步骤,提出了贴近度的改进公式,该公式与传统贴近度公式相比,可以更好的准确快速对毛织物质量评级.根据上述矩阵模型确定了毛织物计算机评价系统流程图,以实例说明了上述模型的实际应用方法.从矩阵模型的特点、方法的准确性、贴近度公式的应用范围、对生产的影响等方面分析了该模糊评价方法的效果.     

机织物透气性预测的投影寻踪回归模型

针对机织物透气性预测中存在非线性建模困难的问题,选择机织物总紧度、厚度、面密度及平均浮长等结构参数作为机织物透气性预测的影响因素,建立机织物透气性预测的投影寻踪回归模型.对模型训练样本的拟合值及检验样本的预测值以相对误差的均值及标准差为指标进行分析,并与BP神经网络及多元线性回归模型进行对比.结果表明,投影寻踪回归模型...     

字型类横截面立体织物同区不同层长短不一致的巧妙设计

为了达到字型类横截面立体织物同区不同层长短不一致的效果,采用穿综时循环次数不同和穿筘时筘入数不同的方法,得到不同长度但密度相同的织物。这种巧妙设计方法适用于有一部分结构是两端不封闭头端的字型类横截面立体织物的设计。