Study on Anisotropy and Punching Yield Strength of Knitted Fabrics

In terms of the structural characteristics, knitted fabrics are described as plane orthotropic body with two symmetric axes, and the stress in different direction is approximately linear with strain before the yield point. The punching yield strength can be predicted theoretically by developing a mathematical equation from anisotropic effect of knitted fabrics. The experimental results demonstrate the applicability of theoretical formula. Analyses also reveal that the factors influencing three-dimensional deforming performance can be divided into two categories: fiber-yarn-fabric structural features and deforming condition.     

Relationships between the Processing Parameters of Melt Blown Nonwoven Fabric and Its Structure and Filtration Property

Based on the processing experiment and sodium flame test this paper deals with the relationship between processing parameters, structure, and filtration property of melt blown fabric. Through the image analysis of Questar micro-images hi combination with the SEM observation and the measurement of some macrostructure indices, the relationship between the processing parameters and the structure especially the microstructure is emphasized. Finally the effect of some structure factors on filtration properties is discussed theoretically.     

基于空间相关性不同组构干热岩裂隙发育

基于以往对干热岩开发的研究,不难发现其主要赋存介质为花岗岩,而此类岩石的组构分布与裂隙发育关系对其开采能效有较大影响。鉴于此,针对花岗岩组构分布与裂隙发育规律的考虑。利用空间相关性函数构建出不同组构的花岗岩表面图像,然后利用离散元数值软件针对图像组构进行建模,结合多种室内试验对数值模型参数进行校准,并进行抗拉强度试验,将裂隙发育情况采用分形维数对进行分析。结果表明：(1)空间相关函数随机场随着其参数的变化能够有效表征岩石内部组构变化情况;(2)随着花岗岩试件组构分布的变化,试件的强度也随之变化;(3)裂隙发育的分形结果表明,矿物组构的不同导致破坏过程中破裂点数目和破裂点发育状态不同,从而对试件的强度产生影响。进而影响干热岩开发的工艺和热交换效率。     

织物三维着装系统中几何建模和纹理映射技术的研究

从几何建模和纹理映射方面介绍了实现高质量的织物三维着装效果的计算机仿真方法。通过B样条曲面构造人体与服装模型,利用基于曲线的纹理映射方法,较好地解决了人体与服装曲面的光滑感以及织物图案“贴”到服装曲面后的变形。     

非织造布结构特性的测试方法及其发展方向

论述了非织造布的几种主要结构特性 (如孔隙大小分布、纤维排列方向分布、网的均匀性及瑕疵等 )的测试方法及其原理与各自的优缺点 .通过对比说明非织造布结构特性的测试方法的发展方向 .     

Characterization of Deformations of Multiaxial Warp Knitted Fabrics during Forming Process

The typical structure(with four inserting yarn systems) of multi-axial warp knitted fabrics shows unsatisfactory conformability according to hemisphere pressing experi-ments.The structure containing only two bias inserting yarn systems(TBMWK fabric),however,proves to possess good conformability.This paper characterized in detail the forming behavior of TBMWK fabric.It was found that the two bias inserting yarn systems tend to gather always along the weft direction,and the angles between them along this direction are basically linear to the perpendicular distances from the measured points to the longitudinal axis of the hemisphere.And the     

Relationship between Light Scattering Intensity and Basis Weight of Non-Woven Fabrics

The relationship between light scattering intensity and basis weight of nonwoven fabrics is studied by using the theory of electromagnetic wave propagation and scatter-ing in random media.The theoretical analysis shows that the backscattering intensity of nonwoven fabric is closely related to its basis weight,and 2 series nonwoven samples manufactured by spun-bonded and thermal-bounded processing methods are tested for checking the theoretical expression.The study shows that the scattering intensity increases with increasing basis weight of nonwoven fabrics in exponential equation,and theoretical expression is consistent with the experimental data.     

基于高斯-马尔可夫随机场模型的织物纹理特征参数提取方法

将高斯-马尔可夫随机场用于织物纹理的建模.在估计模型参数时,采用不完全 Cholesky共轭梯度法.获得特征参数后,通过纹理合成方法,仿真原始纹理图像.试验表明:仿真织物纹理图像与真实织物纹理图像具有较为一致的视觉效果,从而论证了高斯-马尔可夫随机场模型对织物纹理建模的有效性.     

天线罩针刺织物根部结构设计及材料性能研究

针对耐高温天线罩对根部强度及根部材料与金属连接件热膨胀系数匹配性的特殊要求,设计了多种针刺结构石英纤维天线罩织物,并在罩体根部引入氧化铝纤维,系统研究了罩体根部材料的性能情况。结果表明适当降低网毡含量可以提升材料的拉伸性能,但材料的层间剪切强度会有所下降,压缩强度在网毡含量较低的情况下也有所降低。通过在根部引入氧化铝纤维,罩体根部的热膨胀系数有明显提升,但材料的高温拉伸强度随氧化铝纤维含量的增加呈先下降后上升的趋势。文中对相关工艺及材料性能研究为耐高温天线罩的设计提供了参考。     

PVA覆膜对Kevlar纤维表面化学镀Cu层性能的影响

通过聚乙烯醇 (PVA) 覆膜处理的方法提高了Kevlar纤维表面金属镀层稳定性和完整性,从而提升了镀层的抗剥落能力.采用弯折剥离实验考察了镀层的抗剥落破坏情况、采用电阻仪和电子万能试验机测试了试样的导电性和力学性能,利用扫描电子显微镜(SEM)和X射线光电子能谱(XPS)研究了试样的表面形貌和表面化学价态. 结果表明:PVA覆膜能够有效提升金属镀层的抗剥落破坏能力;随着PVA水解浓度的增加,PVA覆膜Cu/Kevlar纤维的表面电阻增加而柔韧性降低;当PVA溶液的水解质量浓度为5 g/L时,PVA覆膜Cu/Kevlar纤维的柔韧性、导电性和抗剥落能力能够维持在最佳状态;在此浓度下,PVA覆膜Cu/Kevlar纤维的表面电阻为0.41 Ω/cm,单丝拉伸强度为2.396 GPa,Weibull分布拟合度为0.988 1.