气密性涂层织物的拉伸性能探讨

测试分析了4种涂层织物涂层前后拉伸性能的变化,结果表明,织物经涂层后其拉伸断裂强度和断裂伸长率都有不同程度的增长,且涂层对织物经、纬向拉伸性能的影响不同。对试验4种涂层织物而言,涂层增重率对织物经纬向拉伸性能的影响不同;在相似增重率条件下,涤纶基布涂层织物的经向拉伸变化率较锦／棉基布涂层织物的显著。     

膜结构用涂层织物拉伸与撕裂性能测试方法及关系研究

为了解决因国内外对膜材的拉伸与撕裂性能进行测试的方法与标准不同而给膜结构设计与选材带来的困难，对比了国内外膜结构用涂层织物拉伸与撕裂性能相关的测试方法与标准，通过对测试方法及试验结果的分析，确定了适合于膜结构用涂层织物的拉伸与撕裂性能的测试方法，找出膜材拉伸强力与撕裂强力一致性的关系，并列出回归方程，分析了影响两者关系的因素。     

柔性多轴向经编聚氨酯涂层织物的拉伸性能

为获得多轴向经编聚氨酯涂层织物的各向增强性能,沿涂层织物0°、22.5°、45°、67.5°和90°5个方向裁取试样,以单轴拉伸试验为基础,分析了织物的拉伸曲线和弹性模量;同时采用数字图像相关系统(DIC),分析了织物的形变特征,计算了泊松比。利用正交各向异性模型对22.5°和67.5°方向的弹性模量和泊松比进行预测。结果表明:该材料具有良好的延伸性,各个方向试样的延伸度均大于400%;越接近67.5°弹性模量越大;由DIC云图分析得知,拉伸初期该材料的横向收缩变形是不均匀的,中间收缩较快,边缘收缩得较慢,而纵向拉伸变形相对均匀;使用正交各向异性关系对涂层织物的弹性模量和泊松比有较准确的预测,误差的绝对值都小于23.69%。     

铜镍金属涂层机织物拉伸过程中电流的响应

为探讨金属涂层机织物作为柔性传感器的传感性能,利用织物强力机和自制电流数据采集系统测试涤纶基金属涂层机织物不同速度下拉伸过程中的电流变化,讨论了电流对拉伸的响应规律,分析了不同拉伸速度对电流响应的影响以及经纬向灵敏度之间的差异。结果表明:涤纶基金属镀层机织物经纬向伸长与电流响应曲线在拉伸速度较高时具有较高的线性度,低速拉伸的电流响应曲线相比高速拉伸线性度差;织物经纬向灵敏度随着拉伸速度的增大而减小,其纬向比经向断裂伸长大,纬向的灵敏度高于经向,低速拉伸时该织物的经纬向均具有较大的灵敏度。     

磁控溅射镀膜时间对涤纶拉伸性能的影响

为研究磁控溅射对纺织品性能的影响，以涤纶长丝织物为基材，采用磁控溅射工艺在其表面镀钛金属膜，然后测试织物中纱线的力学性能，研究了磁控溅射镀膜时间对织物中经、纬纱拉伸性能的影响。研究结果表明，采用磁控溅射工艺可在涤纶表面形成一层致密的纳米级钛膜，且未对织物原有结构造成破坏。经、纬纱的拉伸性能随镀膜时间变化呈现出相似的变化规律，断裂伸长率和断裂功明显降低，断裂强度变化较小。断裂功、断裂伸长率随镀膜时间延长其变化规律如下：在0-150s范围内不断下降；在180s处，重新回到一个较高的水平；在镀膜时间>240s时，又迅速降低。此外，由于经纱在织造过程中承受了较为剧烈的机械作用，使其拉伸性能劣于纬纱。     

基于ABAQUS的三原组织机织物拉伸力学性能模拟

为更好地了解平纹、斜纹和经面缎纹3种基本组织纯棉机织物抵抗外力拉伸变形的能力,在实际测量织物结构参数的基础上,提出一种评价和预测机织物拉伸性能的方法;借助专业纺织建模软件Texgen建立织物三维细观模型;利用有限元软件ABAQUS,依据织物拉伸环境设置材料属性、相互作用和边界条件等计算模型数值解;通过织物拉伸强力测试实验验证数值模拟结果的有效性。结果表明:平纹织物、斜纹织物和经面缎纹织物拉伸应力、应变模拟结果与实验测试结果差异率均在6%以内;在原料、经纬纱密度和捻度、织物经纬密都相同的条件下,平纹织物抵抗外力变形的能力更强。     

机织物拉伸性能有限元模拟计算方法及应用

织物受力拉伸变形时，在应变逐渐增大过程中，织物应力应变本构关系逐渐失去弹性特点，而表现为纺织材料固有的粘弹性质，使织物拉伸变形具有物理非线性特点，本文讨论了具有这些特点的织物受力变形及其分析计算的有限元方法。该方法可以推广到任意类型织物的拉伸性能计算，首先在本文中进行机织物拉伸性能模拟计算 。     

三维间隔织物复合材料的制备及拉伸性能研究

介绍三维间隔织物复合材料的制备方法,并采用Instron 5969型万能材料试验机对三维间隔织物复合材料的拉伸性能进行测试,重点分析间隔高度、经纬向等结构参数对三维间隔织物复合材料拉伸性能的影响。结果表明:三维间隔织物复合材料拉伸性能随间隔高度的增加而下降;纬向拉伸性能优于经向。     

吸波涂层织物的制备及其力学性能研究

探讨吸波涂层织物的吸波性能影响因素及其力学性能。以涤纶针织物为基布,以环氧树脂为基体,在基布上进行铁氧体复合涂层整理,制备0.5mm涂层厚度的柔性纺织涂层复合织物。采用单因子试验法,研究了吸波剂铁氧体含量和环氧树脂含量对吸波涂层织物介电常数的影响,并测试了涂层织物吸波材料的力学性能。结果表明:铁氧体含量为60%,环氧树脂含量为10%时涂层织物具有较好的吸波性能;织物经吸波涂层整理后拉伸强力变化不大,而撕裂强力和胀破性能均有所提高。认为所制备出的吸波涂层复合织物力学性能优于无涂层织物。     

涤纶多轴向经编织物增强柔性复合材料拉伸性能的研究

研究以涤纶经编多轴向织物为基布、表面复合聚氯乙烯压延薄膜制成的新型可作膜结构材料使用的织物增强柔性复合材料的拉伸性能。分析测试结果和图像,并与传统双轴向涂层织物对比,总结该柔性复合材料的优缺点。     

Mechanical Characteristics of Coated Fabrics

When fabrics are coated, their deformation behaviour changes considerably. The tensile, shear, and bending properties of four typical coated fabrics have been measured using the FAST system and an Instron tensile machine. The fabrics were measured before coating, after coating and after subsequent stretching or shearing treatment. Empirical polynomial functions were fitted to the experimental load–extension curves to allow the calculation of strain energies for comparison purposes. Mechanical treatment in the form of stretching or shearing partly restored the original fabric properties and so might be beneficial in apparel applications.     

39—AN ENERGY ANALYSIS OF WOVEN-FABRIC MECHANICS BY MEANS OF OPTIMAL-CONTROL THEORY PART I: TENSILE PROPERTIES

The general energy analysis of fabric mechanics by means of optimal control presented in a previous publication is applied to the woven-fabric structure for deformations whereby the yarns remain in the same plane. The three-dimensional equations of the general theory are reduced to two-dimensional form, the boundary conditions are evaluated for the plain-weave fabric in biaxial tension, and an important mechanism of woven-fabric extension, which was not included in the general analysis, namely, the possibility of yarn extension, is introduced into the theory. The fabric load–extension curves and yarn-decrimping curves for the plain-weave construction are computed for a realistic range of input parameters: the yarn extension rigidity, weave crimp, degree of set, lateral yarn compression, and ratio of the curvilinear length of yarn in the warp direction to that in the weft direction of the fabric. The computed results are discussed in terms of the following dimensionless parameters: the applied tension per thread and the interaction force on the crossing thread (divided by the yarn bending rigidity), the relative fabric extension (the fabric extension divided by the yarn crimp), the initial relative fabric tensile rigidity, the Poisson's ratio of the fabric, and the initial tensile rigidity of the crimped yarn unravelled from the fabric. The tensile properties of plain-weave fabrics in both the grey state and the finished state are illustrated by reference to the computed results, which are also employed to explain the behaviour of yarns during the extension of woven fabrics.     

多轴向经编涂层织物的顶破性能研究

本文对多轴向经编聚乙烯(PE)、聚氨酯(PU)、热塑性聚酯弹性体(TPEE)涂层织物的顶破性形态和失效机理进行了研究。在CRT材料试验机上分别对3种涂层织物进行了准静态顶破实验测试,通过观察顶破过程中涂层织物材料的变形,找出3种涂层织物形变时的异同点。并对实验所得的载荷-位移曲线进行了分析讨论,说明了材料在顶破载荷作用下的失效机理以及不同涂层对织物顶破性能的影响。结果显示,涂层织物的顶破强力主要取决于增强织物,但破坏机理与涂层材料有很大关系。     

A Study of the Mechanical Properties of Woven Silk Fabrics. Part III: A Study of the Extensibility of Continuous-filament Woven Silk Fabrics in the Small-load Region

Continuous–filament woven silk fabrics have a very low tensile modulus in the small-load region compared with woven fabrics of other fibres having a similar structure. In the silk fabrics, there may exist a small gap between the warp and weft threads at their crossover points because of the sericin-removing treatment that is applied after weaving. The tensile behaviour of a fabric with such a gap is considered to consist of two stages. In the first stage, the bent yarn alone is stretched in the initial state of tensile deformation without any mechanical interactions between the warp and weft threads. Since the bending rigidity of silk yarns is small and the gap is relatively large, the tensile modulus of silk fabrics becomes very low in the initial tensile region. After the contact of the warp and weft threads, the soft lateral-compressional property of the silk threads leads to extensibility of the silk fabric. This stage is called here the second stage, in which the tensile and the lateral-compressional deformation properties are mainly concerned with the tensile behaviour of the fabric in this region. Silk–fibroin fibre has a small fibre crimp, and this crimp also makes the silk yarn compressible. In this paper, the extensibility of silk fabrics is analysed, with a theoretical estimation of the extensibility, and an experiment to explain the reason for the high extensibility of silk fabrics is reported.     

Deformation characteristics of flexible PU-coated multi-axial warp knitted fabrics under uniaxial tensile

Based on the characteristics of high tenacity, low density, flexible design, the coated fabric has emerged as a promising construct for tensile test. Here, it reports the deformation mechanism of a PU-coated multi-axial warp-knitted fabric under uniaxial tensile via a digital image correlation system. Specimens produced by us are chase in three fibre-reinforced directions namely 0°, 45° and 90°, respectively. The result shows that the crease does not have an effect on the deformations in the small deformation range (strain < 5%), and the deformation was evidently occurred near the fixed end lags because of the faster movement of specimen at the loading end, and the transverse shrinking at the edges is faster than that in the middle of the specimen. In the large deformation range, the strain fields are inconsistent at the same displacement revealing that the deformations of this kind of flexible coated fabric is in-homogeneous under tensile.     

Finite element analysis of bias extension test using an orthotropic hyperelastic continuum model for woven fabric

In this paper, an orthotropic hyperelastic model of woven fabric has been developed. The model is coded in Abaqus/Explicit using subroutine Vumat. The work reported here covers the influence of the ratio between shearing and tensile rigidities of woven fabric on stress and strain fields. Numerical results from bias extension tests on samples of three aspect ratios are compared to those predict by the theory. This study proved that the shearing deformation depends not only on the specimen dimensions but also on the ratio between shearing and tensile rigidities of woven fabric.     

28—THE PRODUCTION OF WEFT-STRETCH COTTON FABRICS BY SLACK MERCERIZATTON

In the production of weft-stretch fabrics by slack mercerization, weft shrinkage was assisted by the application of high warp tension during mercerization and washing. The addition of a polyethylene lubricant to the post-mercerization resin bath reduced the warp stiffness of the fabric and slightly improved its stretch, performance. At specific warp and weft cover factors, plain weave gave a better stretch performance than twill weaves, although the differences were less than expected. The choice of finer weft than warp yarn facilitated the development of weft crimp. Unless the weft yarn spacing was adequate, however, the weft crimp could not be fully utilized on stretching, because of jamming of the fabric structure during crimp interchange.     

基于ABAQUS的筒状纬编针织物拉伸力学性能模拟

为更好地了解筒状纬编针织物抵抗拉伸变形的能力,基于对织物试样尺寸测量得到的几何结构参数,借助Rhino 3D建模软件建立了纬编针织物线圈模型和筒状纬编针织物模型;同时利用有限元分析软件ABAQUS在单位线圈和筒状织物2个方面研究了筒状纬编针织物的纵向拉伸性能;对织物拉伸过程进行有限元模拟和实验验证,并对针织物拉伸过程中...     

Theoretical analysis of geometrical and mechanical parameters in plain woven structures

An analytic solution for the estimation of structural parameters and initial tensile modulus of plain woven fabrics under uniaxial tensile loading in their linear elastic domain of deformation is presented. For this purpose, a new approach in straight line geometry with a parallel segment to the fabric plane and an inclined segment at the weave intersection in 3D form is proposed which leads to the theoretical estimation of all the structural parameters of plain woven fabrics with saw-tooth geometry. Defining and applying of JJ₂ Ratio in the model enable us to modify the geometrical model and estimate the value of structural parameters considering the history of samples influenced mainly by its manufacturing process. The strain energy method and Castigliano’s theorem are used for the mechanical analysis of the structure. The elasticity, bending, shearing, and compression rigidity of yarns are incorporated into the model. It has been shown that predicting the geometrical and mechanical parameters of woven fabrics before production are possible if and only if the crimp value of the fabrics can be estimated before their production. The proposed theory is validated and compared by applying into some experimental data and a previous model.