The impact of the coupling relationship between projectile size and yarn dimension on the ballistic performance of plain weave fabric

Aramid fibers,due to their relatively high inter-yarn friction,high strength,high modulus,and other characteristics,have become a typical representative of flexible anti-ballistic materials in modern warfare.Current research on the anti-penetration of aramid fabrics mostly focuses unilaterally on the structure and performance of aramid fabrics or the shape and size of projectiles,with fewer studies on the coupled effect of both on ballistic performance.This study analyzes how the coupling relationship(or size effect)between the projectile and fiber bundle dimensions affects the fabric ballistic performance from a mesoscopic scale perspective.Taking plain weave aramid fabric as the research object,considering different diameter projectiles,through a large number of ballistic impact tests and numerical simulations,parameters such as ballistic limit velocity,average energy absorption of fabric,and specific energy absorption ratio(average energy absorption of fabric divided by projectile cross-sectional area)are obtained for ballistic performance analysis.The influence law of projectile size on the ballistic performance of high-performance fabrics is as follows:The relative range of fitted ballistic limit velocity at different target positions gradually decreases and then stabilizes as the projectile diameter increases,indicating that the fabric structure effect gradually disappears at a projectile diameter of 12 mm;The average ballistic limit velocity at three impact positions,P1,P2,and P3,provides the corresponding ballistic limit velocity for 1000D aramid fabric,which increases with projectile diameter but the rate of increase slows down at an inflection point,which in this study occurs where the fabric structure effect nearly disappears at a projectile diameter of 12 mm;The energy absorption ratio increases and then decreases as the projectile diameter increases from 4 mm to 20 mm,reaching a peak at the diameter of 12 mm due to the gradual disappearance of the fabric structural effect.The projectile diameter of 12 mm corresponds to the coupling size of 11.159,which provides a size design reference for the macroscopic-based continuum models of aramid plain weave fabrics.

纺织工程专业本科机织学课程“WEAVE”教学模式创新与实践

为了落实立德树人根本任务,以为国家和社会培养支撑纺织产业转型升级的复合人才为根本目标,结合课程特点、学情分析和教师角色,对纺织工程专业本科机织学课程进行了教学创新探索与实践。坚持以学生学习为中心,建设“WEAVE”教学模式。在“WEAVE”教学模式中,在教学内容、教学方法、教学评价体系方面,注重强调学生在学习中的主体地位,明确教师在学习过程中的辅助作用,引导学生高度参与课堂教学,加深学生对学习目标和学习成果的清晰认知,更好地培养学生的学习能力。“WEAVE”教学模式具有明显的纺织特色,在培养纺织行业人才方面具有一定的优势。

Analysis on the turning point of dynamic in-plane compressive strength for a plain weave composite

Experimental investigations on dynamic in-plane compressive behavior of a plain weave composite were performed using the split Hopkinson pressure bar. A quantitative criterion for calculating the constant strain rate of composites was established. Then the upper limit of strain rate, restricted by stress equilibrium and constant loading rate, was rationally estimated and confirmed by tests. Within the achievable range of 0.001/s-895/s, it was found that the strength increased first and subsequently decreased as the strain rate increased. This feature was also reflected by the turning point(579/s) of the bilinear model for strength prediction. The transition in failure mechanism, from local opening damage to completely splitting destruction, was mainly responsible for such strain rate effects. And three major failure modes were summarized under microscopic observations: fiber fracture, inter-fiber fracture, and interface delamination. Finally, by introducing a nonlinear damage variable, a simplified ZWT model was developed to characterize the dynamic mechanical response. Excellent agreement was shown between the experimental and simulated results.

Influence of Weave Structures on the Tribological Properties of Hybrid Kevlar/PTFE Fabric Composites

The existing research of the woven fabric self-lubricating liner mainly focus on the tribological performance improvements and the service life raised by changing different fiber type combinations, adding additive modification, and performing fiber surface modification. As fabric composites, the weave structures play an important role in the mechanical and tribological performances of the liners. However, hardly any literature is available on the friction and wear behavior of such composites with different weave structures. In this paper, three weave structures （plain, twill 1/3 and satin 8/5） of hybrid Kevlar/PTFE fabric composites are selected and pin-on-flat linear reciprocating wear studies are done on a CETR tester under different pressures and different frequencies. The relationship between the tensile strength and the wear performance are studied. The morphologies of the worn surfaces under the typical test conditions are analyzed by means of scanning electron microscopy （SEM）. The analysis results show that at 10 MPa, satin 8/5 performs the best in friction-reduction and antiwear performance, and plain is the worst. At 30 MPa, however, the antiwear performance is reversed and satin 8/5 does not even complete the 2 h wear test at 16 Hz. There is no clear evidence proving that the tensile strength has an influence on the wear performance. So the different tribological performance of the three weave structures of fabric composites may be attributed to the different PTFE proportions in the fabric surface and the different wear mechanisms. The fabric composites are divided into three regions： the lubrication region, the reinforced region and the bonding region. The major mechanisms are fatigue wear and the shear effects of the friction force in the lubrication region. In the reinforced region fiber-matrix de-bonding and fiber breakage are involved. The proposed research proposes a regional wear model and further indicates the wear process and the wear mechanism of fabric composites.

CAD Method to Design Complex Dobby Weaves with Large Repeats

The principle of a CAD method of converting the pre-designed figures in image form into complex dobby weaves with the appearances similar to the original figures is mainly introduced in this paper. A few designed weaves by the created CAD system are also given as examples of the practical application in the area of complex dobby weave designing.

Quantitative research on the heat affected zone of weave bead welding for Invar alloy

Quantitative research on the heat affected zone （ HAZ） o f weave bead welding （ WBW） joint fo r Invar alloy is carried out in this paper. Based on the morphology and related data analysis of the weld seam, the width difference o f each layer and the forming mechanism are analyzed. Results show that the bottom layer （ Layer 1 ） has the widest HAZ and the smallest fluctuation, which reaches 1 200 ｜jLm. HAZ width o f layer 2 to 5 is relatively narrower which is basically below 600 jjim, while the amplitude fluctuation is greater. The main reason lies in the welding path. The long straight welding without weave causes the base metal near the groove fully melts which causes by the long straight welding without weave, while welding with weave leads to the uneven and inadequate melting of metal near groove.

A Method of Computer Simulation for Derivative Weave and Composed Weave

In this paper, we investigate the method of computer simulation for derivative weave by adopting the way of weave differentiation with mathematical function. And on that base, we explore the way for dealing with composed weave. It is purposed for building a simple and efficient way of computer simulation for weave.

Development of Sichuan Brocade with Imitating Embroidery Effect Based on Free-Floats Interlacing Weave

Owing to the diversity of consumer’s demand, the traditional Sichuan brocade products have to be innovated in order to survive in a competitive environment. Since the construction of traditional Sichuan brocade was composed of basic-weave, the surface of the fabric shows a regular interweaving planar texture and is difficult to represent a three-dimensional effect. Inspired by embroidery handcraft, this paper attempts to achieve the embroidery-like effect on the fabric through the jacquard process. Based on the multi-backed structure of traditional Sichuan brocade, we adopted the zoned-combination design mode and added extra free-floats interlacing weave in the area where we want to show the embroidered effect and arranged the interlacing points by referring to the feature of the pattern. As a result, designed Sichuan brocades by this method are capable of displaying embroidered effect with high realism and three-dimensionality. This approach improves the artistic effect of the traditional Sichuan brocade and provides a technical reference for further texture design of jacquard fabrics.

Method of Weave Design Using the Concept of Auxiliary Dobby Shaft

The craft of auxiliary dobby shaft is one of methods used in the traditional figured woven textiles and especially brocade in China.Based on the principle of auxiliary dobby shaft,a new method of weave design was proposed.The relevant arrangement of warp and weave design were discussed.It is shown that this method can be applied on one electronic jacquard loom with single warp beam for new product development and production.And this effect will open up a new way to reproduce traditional fabrics in order to protect and develop Chinese traditional culture.

3D Woven Structures and Their Weave Design with Changing Cross-section on Warp and Weft Direction

With 3D orthogonal and pseudo-orthogonal weaves, woven sructures with lengthwise and widthwise changing cross section on one side or both sides of the structure can be constructed. The weave formation and the looming draft creation are discussed in this paper which can be used as references to manufacture woven preforms with changing cross sections.

Influence of Weave on Fabric Wrinkle Recovery Property before and after Resin Treatment

Cotton fabrics with different weaves are designed and the influence of weave on wrinkle recovery property and tensile property is analyzed. Weave type plays a prominent part in determining fabric wrinkle recovery property and tensile property. Weave factor C is in direct relation to wrinkle recovery angle and in inverse relation to tensile property. This trend also exists after resin treatment. 3/1 left-twill fabric shows good wrinkle recovery angle and lest tensile loss after resin treatment.

STUDY ON THE MATHEMATICAL MODEL FOR FABRIC WEAVE DESIGN AND ITS APPLICATIONS

In the light of the mapping between[0,1]matrixes of fab-ric weaves,we establish in this paper a mathematical modelfor fabric weave design- One type of non- associative al-gebra composed of 7 basic transformations in a 2- elementfield.In view of practice,we expand the generative set ofmapping of this matematical model to cover the generaltransformation methods in traditional weave design.Takingthe algorethm of" Kronecker product" as an example,wefurthermore illustrate applied potentialities of the generativeset of mapping in the CAD of fabic weaves.

Lei Zu and Can Cong Weaved the Splendid Brocade and the Belt and Road Is Writing a Brilliant Chapter——The Chengdu Consensus of the Academic Seminar on the Land of Abundance and the Silk Road

'Dawn sees saturated reds;the town’s heavy with blooms.'We,more than 90 experts and scholars from home and abroad,attended The Academic Seminar on the Land of Abundance and the Silk Road held by the Association of Chinese Historians,the Guangming Daily Press,the Society for Chinese Archaeology,the Chinese Society on Ancient Capitals,the School of Archaeology and Museology of Peking University,and Sichuan Academy of

Non-woven Industry Weaves a Beautiful Pattern

As one of the three backbone con- sumptions (apparel, home-textile, tech- textile or industrial applications), non- woven textile industry performed well in 2005, but problems still remain. An official from the State Development and Reform Commission - China’s top planner, mapped out economic blue- prints for this fast-growing sector in 2006.

The Impact of Fabric Weave and Anisotropy on the Poisson’s Ratio in Technical Fabrics

Poisson’s ratio changes during the tensile stress of technical fabric samples due to the anisotropy of technical fabrics.This paper examines the effects of the type of weave and the anisotropic characteristics of the technical fabric on maximum tensile force,corresponding elongation,work-to-maximum force,elasticity modulus,and Poisson’s ratio when axial tensile forces are applied to samples cut at various angles in the direction of the weft yarns of the technical fabric.In the lab,3 cotton fabric samples of constant warp and weft density with different structural weave types(plain weave,twill weave,atlas weave)were subjected to the tensile force until they broke at the following angles:0°,15°,30°,45°,60°,75°,90°.Based on the different measured values of technical fabric stretching in the longitudinal direction and lateral narrowing,Poisson’s ratio is calculated.The Poisson’s ratio was calculated up to a relative elongation of the fabric of 8%,as the buckling of the fabric occurs according to this elongation value.According to the results presented in this paper,the type of weave of the fabric,the direction of tensile force,and the relative narrowing of the technical fabrics all play important roles in the Poisson’s ratio value.The Poisson’s ratio curve of a technical fabric under tensile stress(i.e.elongation)is primarily determined by its behaviour in the opposite direction of the elongation.The change in the value of the Poisson’s ratio is represented by a graph that first increases nonlinearly and then decreases after reaching its maximum value.

TMAS is ready to weave success and growth in Vietnam

TMAS,Textile Machinery Association of Sweden,has established a local office in the 7th district of Ho Chi Minh City.Heading the office is Mr.Tran Phuoc Thanh,Business Development Representative for TMAS in Vietnam.Mr.Tran comes with experience from the

基于仿生学的横编保暖面料开发与性能评价

为了研发具有出色热湿性能的针织保暖面料,本文对三类蝴蝶鳞片进行分析,并利用SolidWorks软件建立了几何结构的三维模型。根据模型特征,采用双股13 tex×2羊绒纱线混锦纶热熔丝开发出了三种仿蝴蝶鳞片表面陷光结构针织面料。在此基础上,对仿生结构针织物的保暖性、透湿性和透气性进行了测试,以全面评估其热湿舒适性。其结果表明:以羊绒纱线为原料织造的蝶翅结构仿生织物不仅热湿舒适性能良好,且织造工艺简洁高效,拓宽了从织物组织结构设计方面开发功能纺织品的思路。

基于3D技术的宋锦小花楼织机数字虚拟复原及效果评价

为了更好地实现宋锦小花楼织机及其制作技艺与织造技艺的数字化保护和传播,文章提出一种基于三维建模对宋锦小花楼织机的数字虚拟复原的方法。首先,运用实地调查法对宋锦小花楼织机各项数据进行实地勘测,并运用AUTO CAD软件对宋锦小花楼织机的形制、结构及联动机构进行绘制;其次,运用基于Autodesk 3dsmax三维建模技术对该织机进行数字建模及其制作、织造工艺的数字化动态复原,并运用VRay软件对复原的宋锦小花楼织机进行材质及场景渲染;最后,将宋锦小花楼织机数字复原成果进行综合评价。基于3D技术对宋锦小花楼织机及其制作与织造工艺的数字动态复原,可以有效解决文物的数字化保护、古织机制作技艺与传统织造技艺传播的难题。结果表明,该方法可以完成宋锦小花楼织机及其制作与织造技术的高精度数字化复原,可以有效还原出宋锦小花楼织机及其制作与织造过程的动态展示,为纺织文化遗产与非物质文化遗产的数字化保护提供新的方法。

存量优化视角下葑门横街更新的织补策略研究

中国式城市化的进程给老旧街区发展带来了机遇与挑战,其交通不畅、空间失活、基础设施陈旧等问题明显。随着城市空间逐渐从增量建设向存量优化转型,老旧街区作为存量空间的重要组成部分,其更新改造成为城市建设工作中的重点之一。文章立足存量优化的视角,选取了符合城市更新发展趋势的织补理论,针对苏州葑门横街道路交通、街巷空间、功能业态、文化属性方面的问题,归纳出其更新改造的织补要素,提出了物质和文化层面的织补策略。文章有利于完善和发展织补理论在城市老旧街区小规模渐进式更新中的应用与可持续发展,为城市老旧街区的更新提供更多的基础理论与科学依据。

平纹编织复合材料异形结构的多尺度分析研究

针对平纹编织复合材料的异形结构,研究了在铺层方向拉伸位移加载以及力加载两种工况下,采用刚度体积平均、一致应变边界条件两种计算均匀化方法所得多尺度计算结果的差异性,并将多尺度结果与精细化结果进行了对比。此外,还研究了异形区域划分数量对多尺度计算结果的影响。结果表明,在同一多尺度模型下,两种均匀化方法的σ_(y)应力分布趋势是一致的,并且均与精细化模型结果相吻合。其中位移加载下的多尺度结果与参考结果的mises及σ_(y)应力误差最大只有9.5%和3.3%,并且随着异形结构分区数量的增加,其误差值逐渐减小。而力加载下的结果误差值偏大,随分区数量的增加没有减小的趋势,并且一致应变边界条件的结果整体上大于刚度体积平均的结果。并且,多尺度模型的划分方式会破坏部分结构特征,并在一定程度上影响多尺度结果。