精纺面料的弹性整理和织物性能

探讨全毛精纺面料的弹性整理及整理后织物的物理机械性能．通过适当调整面料设计规格并在后整理工序中采用化学弹性整理，赋予织物经向或纬向弹力，改善了精纺面料的风格及服用性能．同时采用Siro-FAST仪测试了这种弹性面料的性能．试验结果表明：经弹性整理的面料，其面料的弹性指标可以达到天然弹性织物的技术性能指标．FAST仪测试表明：弹性面料具有较好的成形性，不会造成服装加工中线缝起皱和熨烫困难；但面料在弹性方向上的延伸性指标过高、湿膨胀率大，以及弯曲刚度和剪切刚度偏小，给剪裁和缝纫加工造成一定困难．     

不同模量石墨简支梁的弹塑性分析及试验研究

石墨烯是一种强度最大、具有拉压不同弹性模量的材料.石墨是石墨烯的原材料,由于其良好的耐辐照性能,广泛地应用于国防核工业,研究石墨的不同模量力学特性正在成为一种新的研究趋向.实验测试了MSL82型号石墨的力学行为,证明并得到石墨材料的拉压不同模量比值.同时建立了不同模量弯曲梁的弹塑性分析理论模型.通过与测试数据的比较,验证了模型的准确性.研究表明:不同模量石墨梁在弹性阶段,中性轴的位置偏向下方受压侧,但不随荷载变化;拉压模量比对截面的应力分布影响很大,减小拉压模量比,可减小最大拉应力;而增大拉压模量比,则可以减小最大压应力.进入塑性阶段后,随着外荷载的增加,中性层的位置上升,最终的位置由拉压屈服极限的比值决定;随着截面的塑性发展,拉压模量比对截面应力分布的影响逐步减小,但对应变的影响仍然较大.因此,可通过改变拉压模量比来控制截面的最大拉压应变.     

PTT经编弹力泳装面料弹性的研究

为了解新型聚酯纤维PTT(聚对苯二甲酸丙二醇酯)经编弹力泳装面料的弹性,用PTT纤维织制的经编弹力泳装面料,与锦纶(PA)和涤纶(PET)织制的经编弹力泳装面料进行对比研究.实测了它们15N和5次及25N和9次定负荷的拉伸性能,比较了它们的弹性回复率、塑性变形率和拉伸弹性伸长率;为进一步寻找3种面料的弹性回复率变化规律,列出了它们弹性回复率的回归方程式.结果显示,PTT经编弹力泳装面料断裂强力较小、伸长率较大,具有优异的弹力回复性,是制作泳装的理想面料.     

应力条件下单壁氮化硼纳米管结构、力学和电学性质

采用第一性原理赝势平面波方法,研究了单壁氮化硼(BN)纳米管在应力条件下的结构、力学和电学性质。计算了不同类型氮化硼纳米管的弹性模量、拉伸强度和Poisson比。结果表明:氮化硼纳米管具有与碳纳米管相同量级的弹性模量(TPa量级)和拉伸强度(GPa量级),可以当作稳定的基体材料用于复合材料的合成中。同时发现:在拉伸情况下,氮化硼纳米管的结构和能带结构均发生一定规律的变化,能隙逐渐减小。这表明,氮化硼纳米管可以用作nm级别的力学传感器。     

A New Measurement System for Static and Dynamic Clothing Pressure

This study aims to develop a system and measurement method for investigating the static and dynamic pressure behavior of compression products.The self-designed measurement system,named "cloth-press" ( LLY-56B).is a direct measurement method,which is based on a rigid hemisphere with three pressure sensors distributed on its surface.The static pressure is measured at predetermined press depth,and the dynamic pressure is measured under the processing of fabric 3D deformation.The pressure distributions at the basic three sites are accepted as the measurement results.The measurement results provide much information in the field of compression fabric assesment,and the measurement system can be used in scientic research institutes and factories,contributing to optimize process parameters and quality control of compression garment.     

Effect of Fabric Elongation on the Making Up of Pressure Garments

Pressure garments are widely used in Hong Kong andmany other countries for burn rehabilitation.Thesegarments are mainly made of elastic Lycra fabrics andtailor-made to individual patient's measurement toprovide an appropriate amount of skin-garment in-terface pressure for medical treatment.However,thefabric tension would be reduced due to fabric elonga-tion under prolonged period of stress,and thus theskin-garment interface pressure cannot be main-tained after repeated use of the garment.This paperaims to study the behaviour of fabric elongation of thefabrics commonly used for making pressure garmentsin U.K.and/or Hong Kong.Attempts to correct theexisting practice of drafting the pressure garments forproviding a more effective clinical treatment.     

Effect of Splice Marking on Fabric Roll Planning

Minimising the fabric loss during spreading can reduce the total production costs of garment manufacturing. Although marker planning is a major determinant of material utilisation, considerable savings on materials also will be made from the area of spreading loss. In the spreading process, it is general to have variance on the fabric yardage between each fabric roll, and the number of splice markings on each cutting lay is also varied. This paper aim to study how the fabric roll planning and the number of splice marks of a cutting lay will affect the material usage in the spreading process. By using a genetic algorithm approach, the amount of fabric to be saved by optimising the fabric roll sequence was derived by comparing the best arrangement and the worst arrangement of the fabric roll sequences of a cutting lay. The result of the study showed that both fabric roll planning and the number of splice marking have effect on the fabric loss. The findings could help the apparel manufacturer to reduce the     

A STUDY OF THE SPECIMEN SIZE OF STRIP TENSILE TEST FOR NEEDLE-PUNCHED NON-WOVEN GEOTEXTILES

In this paper,the failure features of strip tensile specimen were observed and analysed for need-le-punched non-woven geotextiles.A mechanical model which expresses the relation between thetensile modulus,the strip specimen size,contraction factor and the tensile strength of non-wovenfabric was derived.The theoretical prediction showed that the main factor influencing tensilestrength of non-woven geotextile specimens with different size is the contraction factor of specimenor the specimen aspect ratio(width/length).The larger the aspect ratio,the higher the tensilestrength test value of geotextiles,but the experiments showed that the specimen tensile strength isnot increased with increasing the width of specimen.The reason was discussed and it seemed thatthe deviation could be served as an indication of the degree of imperfectness of the non-wovenstructure.     

A Study of Interface Pressure at the Seamed Area of Pressure Garments

Pressure garments constructed with elastic fabric play an important role in burn rehabilitation by helping to prevent or reduce the formation of hypertrophic scars. For clinical effectiveness, these garments are made in appropriate size for individual patient in order to provide an appropriate amount of skin-and-garment interface pressure on the patient.The seam area of pressure garments has marked impact on the comfort and durability of the pressure garments.Comments from the patients and occupational therapists have indicated that discomfort arose in the seam zone.Line marks appeared on the skin of patients under the seamed areas of pressure garments. This may be caused by uneven or Iocalised interface pressure at the seamed area. In this paper, the changes of interface pressure between the seamed and unseamed areas were investigated. The aim is to provide an understanding of the effect of seams on the interface pressure in order to assist the therapists and/or garment makers to choose an appropriate s     

Flexural Properties of Weft Knitted Fabric Reinforced Composites

Several different kinds of weft knitted fabrics from glass fiber yarns were used as reinforcement to make fabric/ polyester composite laminates. Flexural tests were carried out to examine stress-deflection process and compare the mechanical properties in course and wale directions of these composites. The experimental results indicate that the numbers of load-bearing yarn in course and wale direction and the fabric density are the main factors influencing the ultimate tensile strength and initial elastic modulus of specimens.     

不同拉压模量弹性地基梁的解析解

采用拉压不同模量理论,推导了不同模量弹性地基梁的解析解.研究得到的解析解拓展了经典力学理论,并且当拉压模量相同时,该解可以退化到经典理论解.将结果与经典力学同模量理论比较表明:研究得到的解析解能很好地考虑了拉压不同模量效应.为此,合理设计材料的拉压模量比值,可以显著的改变地基梁的弹性特征值、内力及挠度值.该理论遵循材料实际的力学行为,在实际工程设计中大大提高了材料的利用率,达到节约能源的目的,具有重要的工程意义.     

单梳经平织物增强复合材料拉伸性能试验研究

在拉舍尔舌针经编机上编织了6种玻璃纤维单梳经平织物,采用手糊工艺将其与不饱和聚酯树脂复合.在万能材料试验机上测试了单梳经平织物增强复合材料试样的拉伸性能,并对其纵向、横向与斜向应力-应变曲线、弹性模量、断裂强度等进行了分析.结果表明,单梳经平织物增强复合材料的拉伸性能具有明显的正交各向异性特征;织物结构参数的变化,导致了线圈形态、延展线的长度和取向等的差异,使复合材料的拉伸性能不同.     

关于脆弱生丝织造性能的研究

将正常生丝、脆弱生丝、经柔软剂处理的脆弱生丝一起作为经丝上机织造,比较它们织造过程中断头、张力情况,并对织物的拉伸性能、染色性能作对比分析,结果表明:脆弱生丝经柔软处理后断头次数明显减少,织物强力有所增加,但与正常生丝一起染色存在色差.     

Subjective and Objective Measurements to select Fabric for Child Patients' Garment

This paper studies on fabrics suitable for child patients'garment in the hospital environment in Hong Kong,China.Subjective measurement was carried out by questionnaire survey to consult medical staff on hospital requirement about fabric criteria for child patients' garment. On the other hand, objective measurement was conducted by performing laboratory tests on fabrics,which were sourced from commercial fabric market. Both measurements are evaluated according to the results on those fabric criteria in order to determine the most suitable kind of fabric for the end purpose. As a result of the comparison, it was found that T/C 1 scores the highest index. Therefore, it will be suggested for manufacturing child patients' garment to evaluate the fabric suitability to meet the wearers' requirement through hospital trial.     

Plasma Modification of Wool: The Effect of Plasma Gas on the Properties of the Wool Fabric

The wool fabrics were treated with low temperature plasma (LTP) using three different gases, namely (ⅰ) oxygen, (ⅱ) nitrogen and (ⅲ) 25％ hydrogen/75％ nitrogen gas mixture. After LTP treatment, the low stress mechanical properties, surface properties and thermal properties of the fabrics were investigated by kES-F (Kawabata Evaluation System) Instruments composing of KES-FBI for tensile and shear property measurement, KES-FB2 for pure bending measurement, kES-FB3 for compression measurement, KES-FB4 for surface friction and surface roughness measurement, and KES-F7 for thermal property measurement. The first four instruments were used for investigating the charaeterlstlc aspect related to fabrle hand while the last one was mainly for the fabric comfort. The properties of LTP treated fabrics under the effect of different gases were compared with the untreated fabric quantitatively.     

Dependence of Softness on Fabric Surface Quality and Compressibility

The term ＂softness＂ is loosely used to describe the physical as well as sensory attributes of fabric and other textiles, and several psychophysicai evaluation methods as well as its predicting equations exist. However, the information for physiological mechanism of fabric softness is lack. To explain the blomechauical and the potential neurophysiologicai phecnomenon for exploring fabric softness, accompanying to the procedures in manual exploration for softness and the anatomical multllayor structures of human finer, a contact finite dement （FE） model between finger and fabric is made to conduct an active contact analysis. In present FE model, the effect of surface friction index, compression modulus, Poisson＇s ratio of fabric on softness dlscrimination is Investigated. The interests are in the contributlons of these fabric property variables to contact area, Interracial friction shear stress and contact pressure distributions, which arc significant cognitive variables or stimulus parameters in peripheral neural levels. The mechanistic data for fabric specimens indicates that the basis for the perception of softness of flexible and bulk fabric is likely on the spatial variation of pressure on the skin （or, equivalently the skin displacement and its derivatives） resulting from surface friction phenomenon and compression property of fabric. In present model, however, the effect of Poisson＇s ratio on the total force exerted by fingertip is not significant statistically. Therefore, compression modulus of fabric is, not the only underlying physical variable accounting for peripheral neural response, and also the surface friction phenomenon plays an important role in feeltouch softness of fabric, i.e. the compressibility and surface properties of fabric arc the necessary physical variables involved for the haptic rendering of its softness.     

轻薄府绸织物斜向强伸性能与接缝强力的关系

研究了轻薄织物各向异性与接缝强力的关系，轻薄织物斜向强伸性对接缝强力有明显影响，织物斜向接缝强力主要与织物断裂伸长率有显著相关性，相关系数为0．7389。     

混凝土初始损伤细观结构特性数值试验研究

细观结构特性是混凝土材料最重要的特性之一,细观结构参数的改变直接影响混凝土弹性模量、抗拉抗压强度等宏观力学性能变化.首先采用混凝土随机骨料模型进行混凝土细观数值试验,将混凝土看成由骨料、水泥砂浆以及两者之间的界面过渡区(ITZ)组成的三相复合材料,并在水泥砂浆中引入不同孔径、孔隙率的孔隙,使用有限元分析软件MSC.Marc,通过数值试验研究了孔径、孔隙率对混凝土抗拉抗压强度和弹性模量的影响规律.试验结果表明:混凝土弹性模量在同一孔径下随着孔隙率的增长呈线性下降,在同一孔隙率下随着孔径增大呈对数下降;混凝土抗拉抗压强度随着孔隙率和孔径增大呈对数下降.其次,将数值试验结果与经验公式进行了对比,验证数值试验结果的正确性.最后,根据数值试验结果,建立了混凝土初始损伤与孔隙率和孔径之间的关系,描绘了细观尺寸下混凝土的初始损伤面,为建立混凝土细观结构参数和宏观力学特性之间的联系,改善混凝土的力学性质打下了基础.     

Influence of Wires Properties on Warp-Knitted Loop Geometry in Plane Based on Theory of Elastic Rod

Based on classic theory of elastic rod,the warp-knitted loop geometry in plane is independent of yarn properties,while there is a certain gap between the geometrical model and the actual fabrics.According to this problem,further analysis of loop geometry is done based on the theory of elastic rod with theoretical calculation and experiments.The theoretical analysis found that the distance between the contacted points at the loop root affected the loop geometry,and the distance was affected by the ratio of bending rigidity and the friction between yarns.The experiments,forming simple loop by taking the yarn as an elastic rod,found that the bending rigidity affected the loop geometry.Then the relationships between warp-knitted loop geometry in plane of metallic fabrics and wires properties were studied.The results show that metallic fabrics are more suitable for the theory of elastic rod;the friction and bending rigidity of wire yarns affect the loop geometry in plane.Also,the elongation of yarn affects the loop geometry in the actual warp-knitted fabric.     

Theoretical Analysis of the Factors Affecting Splice Loss During Fabric Spreading

Material utilization is mainly concerned by industrialpractitioners since it contributes to minimize the totalproduction costs for garment manufacturing. Apart fromthe marker loss, splice loss (the fabric loss during thejoining of different fabric rolls) is one of the primarycauses of fabric loss, but it has not been considered spe-cifically in the past literatures. The amount of splice lossduring fabric spreading is governed by various factors in-cluding the marker length, the number of fabric rolls,and the number of splicing intervals for laying-up. Inour study, these three effects on splice loss during fabricspreading were computed and analysed.