An experimental investigation of the yarn pull-out behavior of plain weave with leno and knitted insertions

2019 ◽  
Vol 89 (21-22) ◽  
pp. 4717-4731 ◽  
Author(s):  
Zhou Yi ◽  
Muhammad Ali ◽  
Xiaozhou Gong ◽  
Hanming Dai ◽  
Deng Zhongmin
Keyword(s):  
Experimental Investigation ◽  
Vital Role ◽  
Woven Fabrics ◽  
External Loading ◽  
Rupture Force ◽  
Plain Weave ◽  
Pull Out ◽  
Ballistic Protection ◽  
Protection Systems ◽  
Sliding Force

Yarn–yarn sliding force plays a vital role in absorbing impact energy for plain fabrics. This paper reports the methods and results of an investigation on the mechanisms that enable higher yarn pull-out force of woven fabrics with the incorporation of lenos and knits. The experimental results suggested that the insertion of leno lines on plain weave gives an approximately 20% increase in junction rupture force over the original plain construction. With knitted structures inserted, the structure-modified fabrics showed a junction rupture force up to about 15 times higher than simple plain weave. It was even found that the yarns failed rather than pulled out in multiple yarn pull-out tests. This is because knitted structures tend to become self-locked and consequently restrict yarn displacement when subjected to external loading. This investigation reports a method to increase the frictional force between the warp and weft yarns based on textile technologies. It is expected that the results obtained could provide some useful information for the engineering design of flexible ballistic protection systems.

An overview of yarn pull-out behavior of woven fabrics

2017 ◽  
Vol 89 (2) ◽  
pp. 223-234 ◽  
Author(s):  
Yi Zhou ◽  
Muhammad Ali ◽  
Xiaozhou Gong ◽  
Dan Yang
Keyword(s):  
Experimental Testing ◽  
Woven Fabrics ◽  
Body Armor ◽  
Woven Fabric ◽  
Flexible Body ◽  
Stick Slip ◽  
Pull Out ◽  
Ballistic Protection ◽  
Modeling Techniques ◽  
Gripping Force

This paper reviews the topic of yarn pull-out on a plain woven fabric. It deals with previous works on experimental testing and theory exploration regarding this process, also including the prominent stick-slip behavior and the associated modeling techniques. Finally, it discusses the advances in chemical treatment and construction modification for the increase in yarn gripping force. The current paper serves as a source of literature for those willing to undertake additional research in this area and for those interested in developing flexible body armor with improved ballistic protection.

Magnetorheological Damping of Fragment Barrier Suspension Systems

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Kwon Joong Son ◽  
Eric P. Fahrenthold
Keyword(s):  
Ballistic Performance ◽  
Mr Fluid ◽  
Suspension Systems ◽  
Mr Fluids ◽  
Ballistic Protection ◽  
Protection Systems ◽  
Fluid Damping ◽  
Magnetorheological Damping ◽  
Impact Experiments ◽  
Very High

Magnetorheological (MR) fluids, well established as components of a variety of suspension systems, may offer opportunities to improve the performance of fabric ballistic protection systems, which typically do not incorporate significant energy dissipation mechanisms. A series of ballistic impact experiments has been conducted to investigate the potential of MR fluid damped fabric suspension systems to improve upon current fabric barrier designs. The results indicate that for the simple fabric suspension systems tested, MR fluid damping does not improve upon the very high weight specific ballistic performance of state of the art aramid fibers.

scholarly journals Analytical investigation of high-velocity impact on hybrid unidirectional/woven composite panels

2016 ◽  
Vol 30 (4) ◽  
pp. 545-563 ◽  
Author(s):  
H Shanazari ◽  
GH Liaghat ◽  
H Hadavinia ◽  
A Aboutorabi
Keyword(s):  
Cross Sections ◽  
Shear Failure ◽  
Failure Criteria ◽  
Analytical Investigation ◽  
Woven Fabrics ◽  
Body Armor ◽  
Ballistic Performance ◽  
Nonwoven Fabrics ◽  
Ballistic Protection ◽  
Maximum Tensile Strain

In addition to fiber properties, the fabric structure plays an important role in determining ballistic performance of composite body armor textile. Textile structures used in ballistic protection are woven fabrics, unidirectional (UD) fabric structures, and nonwoven fabrics. In this article, an analytical model based on wave propagation and energy balance between the projectile and the target is developed to analyze hybrid fabric panels for ballistic protection. The hybrid panel consists of two types of structure: woven fabrics as the front layers and UD material as the rear layers. The model considers different cross sections of surface of the target in the woven and UD fabric of the hybrid panel. Also the model takes into account possible shear failure by using shear strength together with maximum tensile strain as the failure criteria. Reflections of deformation waves at interface between the layers and also the crimp of the yarn are modeled in the woven part of the hybrid panel. The results show greater efficiency of woven fibers in front layers (more shear resistance) and UD yarns in the rear layers (more tensile resistance), leading to better ballistic performance. Also modeling the yarn crimp results in more trauma at the backface of the panel producing data closer to the experimental results. It was found that there is an optimum ratio of woven to UD materials in the hybrid ballistic panel.

scholarly journals Partial Replacement of Cement by Neem Leaves Ash and Fly Ash

2020 ◽  
Vol 9 (1) ◽  
pp. 506-508
Keyword(s):  
Experimental Investigation ◽  
Fly Ash ◽  
Ordinary Portland Cement ◽  
Construction Materials ◽  
Strength Properties ◽  
Vital Role ◽  
Partial Replacement ◽  
Cement Ratio ◽  
Neem Leaves ◽  
The World

Concrete is the most essential construction materials in all over the world. It is necessary to search the cheaply obtainable material as admixture which might be partially replaced cement in the production of concrete. This project is an experimental investigation of the neem leaves ash as partial replacement for cement also fly ash is used for partial replacement of cement. The neem leaves were dried, burnt and heated in the furnace to produce Neem leaves Ash, which was discovered to posses Pozzolanic properties.the ordinary Portland cement was replaced by neem ash by 5%,10%,15%,20% and 25% by weight also flash replaced by 15%,20%,25% and 30% the cubes were crushed to know the comparative strength of the concrete at different curing days. The last result showed that workability and strength properties of the concrete was depended on water cement ratio, total days of curing, the percentage of replacement of Neem leaves ash for OPC . I. This project it was noticed that the result of 5% NLA and 15% fly ash and 10% NLA and 20% of fly ash were gradually increasing the strength at 28 days. Neem leaves play a vital role and behaviour of Neem leaves ash and flash used concrete will be studied

scholarly journals The influence of thermal fixation of interlining on the quality of woven clothing fabrics evaluated from the aspect of their electrical resistance

2020 ◽  
Vol 68 (4) ◽  
pp. 4-11
Author(s):  
Koviljka Asanović ◽  
Tatjana Mihailović ◽  
Mirjana Kostić ◽  
Iva Gajić ◽  
Aleksandra Ivanovska
Keyword(s):  
Electrical Resistivity ◽  
Ambient Air ◽  
Polyester Fabric ◽  
Woven Fabrics ◽  
Plain Weave ◽  
Weave Fabric ◽  
Polyester Fibers ◽  
Electrical Resistivities ◽  
Twill Weave

In this paper, the influence of thermal fixation of woven interlining on the quality of woven fabrics, evaluated from the aspect of their dc volume electrical resistivity, was investigated. The plain weave fabrics made from cotton, flax, viscose, polyester, and cotton/polyester blends and 3/1S twill weave fabric obtained from cotton and polyester fibers blend were investigated. A cotton fabric with a point-applied thermoplastic binder was used as an interlining. The obtained results showed that the dc volume electrical resistivity of fabrics is influenced by their chemical composition, type of weave, type of yarn, fabric density which is especially pronounced in the interlining, the process of thermal fixation of the interlining, and ambient air humidity. The thermal fixation of the woven interlining greatly reduces the dc volume electrical resistivity of polyester fabric (499 times in the warp direction and 860 times in the weft direction), and increases the resistivity of other fabrics in the range of 1.3 times for viscose fabric and fabric obtained from cotton and polyester fibers blend in plain weave to 3.9 times for twill weave fabric. Based on the conducted investigation, it can be concluded that the quality of the tested fabrics evaluated from the aspect of their electrical resistivities, was significantly improved in the case of polyester fabric i.e worsens in the other investigated fabrics after thermal fixation of the woven interlining.

Experimental Investigation of Adhesive Bonding for Post‐installed Rebars into Concrete at High Temperatures

2019 ◽  
Author(s):  
Thanyawat Pothisiri ◽  
Pitcha Jongvivatsakul ◽  
Vanichapoom Nantavong
Keyword(s):  
Experimental Investigation ◽  
High Temperatures ◽  
Mechanical Behaviour ◽  
Epoxy Resins ◽  
Adhesive Bonding ◽  
Elevated Temperatures ◽  
Adhesive Bond ◽  
Steel Rebar ◽  
Pull Out ◽  
Embedment Length

<p>The use of post‐installed rebars into existing reinforced concrete structures bonded with epoxy resins was constantly increasing due to the advantage of equivalent or even higher bearing capacities at service temperature, compared with conventional cast‐in‐place rebars. Previous studies have examined the effects of different parameters on the mechanical properties of bonded post‐installed rebars at normal temperature. These studies showed that, for rebar diameter equal to 10 mm, the load bearing capacity increases linearly with the embedment length up to 75 mm. However, upon exposure to high temperatures, the glass transition of epoxy resins may occur and affect the mechanical behaviour of the adhesive bond. Studying the mechanical behaviour of an adhesive anchor at high temperatures is therefore necessary. An experimental investigation is conducted herein to examine the characteristics of the adhesive bonding stress between steel rebar and concrete interface at elevated temperatures using a series of pull‐out tests with varying rebar diameters and embedment lengths.</p>

An Experimental Investigation of the Effects of Clamped Length and Loading Direction on Self-Loosening of Bolted Joints

2004 ◽  
Author(s):  
Ming Zhang ◽  
Yanyao Jiang ◽  
Chu-Hwa Lee
Keyword(s):  
Experimental Investigation ◽  
Fatigue Curve ◽  
Relative Displacement ◽  
The Self ◽  
Bolted Joints ◽  
Transverse Load ◽  
External Loading ◽  
Loading Direction ◽  
Controlling Parameter ◽  
Load Carrying

An experimental investigation was conducted to study the effects of clamped length and loading direction on the self-loosening behavior of bolted joints. Specially designed fixtures were used for the study. The experiments mimicked two plates jointed by an M12×1.75 Class 10.9 bolt and a nut. The joints were subjected to cyclic external loading. A constant preload of 25 kN was used for all the experiments conducted. During an experiment, the relative displacement between the two clamped plates, δ, was a controlling parameter. The reduction in clamping force, the applied transverse load, and the nut rotation were measured cycle by cycle. The relationship between, Δδ/2, the amplitude of the relative displacement between the two clamped plates, and, NL, the number of loading cycles to loosening is referred to as self-loosening curve and was obtained for different clamped lengths and applied load directions. Similar to a fatigue curve, an endurance limit can be identified from the self-loosening curve. It was found that increasing the clamped length can enhance the self-loosening endurance limits in terms of the controlled relative displacement of the two clamped plates. However, the load carrying capability was not influenced significantly due to the thickness of the clamped plates. For a given bolted jointed structure, an angle of the external load from the pure shearing direction resulted in an increase in self-loosening resistance.

scholarly journals Shear-Thickening Fluid Using Oxygen-Plasma-Modified Multi-Walled Carbon Nanotubes to Improve the Quasi-Static Stab Resistance of Kevlar Fabrics

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1356 ◽  
Author(s):  
Danyang Li ◽  
Rui Wang ◽  
Xing Liu ◽  
Shu Fang ◽  
Yanli Sun
Keyword(s):  
Carbon Nanotubes ◽  
Loss Modulus ◽  
Shear Thickening ◽  
Woven Fabrics ◽  
Body Armor ◽  
Shear Thickening Fluid ◽  
Pull Out ◽  
Stab Resistance ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The excellent mechanical property and light weight of protective materials are vital for practical application in body armor. In this study, O2-plasma-modified multi-walled carbon nanotubes (M-MWNTs) were introduced into shear-thickening fluid (STF)-impregnated Kevlar woven fabrics to increase the quasi-static stab resistance and decrease the composite weight. The rheological test showed that the addition of 0.06 wt. % M-MWNT caused a marked increase in the peak viscosity from 1563 to 3417 pa·s and a decrease in the critical shear rate from 14.68 s−1 to 2.53 s−1. The storage modulus (G′) and loss modulus (G″) showed a higher degree of abrupt increase with the increase of shear stress. The yarn pull-out test showed that the yarn friction of M-MWNT/STF/Kevlar fabrics was far superior to the original fabrics. Importantly, under similar areal density, the M-MWNT/STF/Kevlar fabrics could resist 1261.4 N quasi-static stab force and absorb 41.3 J energy, which were much higher than neat Kevlar fabrics. The results of this research indicated that quasi-static stab resistance was improved by M-MWNTs, which was attributed to the excellent shear-thickening effect and the high yarn friction. Therefore, M-MWNT/STF/Kevlar fabrics have a broad prospect in the fields of body protection.

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