scholarly journals A Study of Woven Fabrics Made of Helical Auxetic Yarns

2021 ◽  
Author(s):  
Yajie Gao ◽  
Xiaogang Chen
Keyword(s):  
Poisson’S Ratio ◽  
Numerical Study ◽  
Tensile Modulus ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Poisson's Ratio ◽  
Key Factors ◽  
Warp Yarn ◽  
Weave Structure ◽  
Best Parameters

AbstractThe paper presents a study on woven fabrics made of helical auxetic yarns (HAYs) and their key factors on Poisson’s ratio under tension. The work aims to create and evaluate auxetic woven fabrics with optimal parameters for achieving better auxeticity including weave structure, wrapping angle of the auxetic yarn, thickness of the auxetic yarn and properties of the warp yarn. The maximum negative Poisson’s ratio (NPR) of the woven fabric can be achieved as low as -2.92 for experiments. Then, a numerical study has been carried out as well to assist the development of auxetic woven fabrics. The findings of this paper showed longer float length, lower wrapping angle of the auxetic yarn, a thinner diameter of the auxetic yarn as well as lower tensile modulus of the warp yarn led to higher auxetic behaviour. This can also provide a reference for researchers to select the best parameters for producing the auxetic woven fabrics.

Deformation behavior of auxetic woven fabric made of foldable geometry in different tensile directions

2020 ◽  
Vol 91 (1-2) ◽  
pp. 87-99
Author(s):  
Hasan Kamrul ◽  
Weiguo Dong ◽  
Adeel Zulifqar ◽  
Shuaiquan Zhao ◽  
Minglonghai Zhang ◽  
...  
Keyword(s):  
Poisson’S Ratio ◽  
Tensile Deformation ◽  
Tensile Loading ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Poisson's Ratio ◽  
Negative Poisson’S Ratio ◽  
Ratio Effect ◽  
Negative Poisson's Ratio ◽  
Principal Directions

Auxetic woven fabrics made with special geometrical structures have gained the interest of textile scientists in recent years. This paper reports a study on auxetic woven fabric based on a double-directional parallel in-phase zig-zag foldable geometrical structure. Such a fabric has been already produced and investigated for its negative Poisson's ratio effect in two principal directions (weft and warp directions). However, its negative Poisson's ratio effect in biased tensile directions as well as under repeated tensile loading conditions has not been studied yet. Therefore, in this paper, these two limitations are addressed. The auxetic woven fabric was firstly fabricated, and then subjected not only to tensile tests in different tensile directions, including two principle directions and three biased directions, but also to repeated tensile loading. It was found that both the negative Poisson's ratio effect and the resistance to tensile deformation are dependent upon the tensile direction, and the highest negative Poisson's ratio effect and higher resistance to tensile deformation are obtained in two principal directions.

scholarly journals The manufacture and characterization of auxetic, self-curling, and self-folding woven fabrics by helical auxetic yarns

2018 ◽  
Vol 50 (1) ◽  
pp. 3-12
Author(s):  
Sai Liu ◽  
Xingxing Pan ◽  
Dongming Zheng ◽  
Gui Liu ◽  
Zhaoqun Du
Keyword(s):  
Poisson’S Ratio ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Poisson's Ratio ◽  
Natural State ◽  
Practical Applications ◽  
Maximum Value ◽  
Auxetic Structures ◽  
The Relationship

Auxetic fabrics with traditional filaments and auxetic structures have been provided by knitting method; however, the auxetic behavior and applicability of woven fabric with auxetic yarns remain to be studied. Thus, the paper aims to present the special characters of woven fabrics with heliacal auxetic yarns. Auxetic yarns with the maximum value of Poisson's ratio −0.88 were used as weft yarns to do the weaving by the semi-automatic loom. Then the properties of the fabrics have been tested and analyzed under tensions of different directions (warp, weft, and diagonal). The results indicated that the fabric presented auxetic effect with the maximum value of Poisson's ratio −0.3 under diagonal tension and also showed self-curling and self-folding behavior in natural state. Moreover, the relationship between properties and fabric weaves was also discussed and analyzed. It is expected that the study of fabrics with helical auxetic yarns could promote the practical applications of auxetic textiles such as the self-folding property for smart cladding materials.

scholarly journals Representative volume element based micromechanical modelling of rod shaped glass filled epoxy composites

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Aanchna Sharma ◽  
Yashwant Munde ◽  
Vinod Kushvaha
Keyword(s):  
Representative Volume Element ◽  
Poisson’S Ratio ◽  
Volume Fraction ◽  
Tensile Modulus ◽  
Volume Element ◽  
Poisson's Ratio ◽  
Epoxy Composites ◽  
Micromechanical Modeling ◽  
Representative Volume ◽  
Shaped Glass

AbstractIn this study, Representative Volume Element based micromechanical modeling technique has been implemented to assess the mechanical properties of glass filled epoxy composites. Rod shaped glass fillers having an aspect ratio of 80 were used for preparing the epoxy composite. The three-dimensional unit cell model of representative volume element was prepared with finite element analysis tool ANSYS 19 using the periodic square and hexagonal array with an assumption that there is a perfect bonding between the filler and the epoxy matrix. Results revealed that the tensile modulus increases and Poisson’s ratio decreases with increase in the volume fraction of the filler. To study the effect of filler volume fraction, the pulse echo techniques were used to experimentally measure the tensile modulus and Poisson’s ratio for 5% to 15% volume fraction of the filler. A good agreement was found between the RVE based predicted values and the experimental results.

scholarly journals Effect of Fabric Structure and Weft Density on the Poisson's Ratio of Worsted Fabric

2013 ◽  
Vol 8 (2) ◽  
pp. 155892501300800 ◽  
Author(s):  
Nazanin Ezaz Shahabi ◽  
Siamak Saharkhiz ◽  
S. Mohammad Hosseini Varkiyani
Keyword(s):  
Poisson’S Ratio ◽  
Uniaxial Extension ◽  
Poisson's Ratio ◽  
Weft Yarn ◽  
Combination Effect ◽  
Weft Direction ◽  
Weave Structure ◽  
Fabric Structure ◽  
Fabric Structures ◽  
High Linear Correlation

This paper investigates the impacts of weave structures and weft density on the Poisson's ratio of worsted fabric under uniaxial extension. In this study nine groups of worsted fabrics comprising of three weave structures (twill 2/2, twill 3/1 and hopsack 2/2), each produced in three different weft densities were examined. Samples were extended in weft direction uniaxially and the Poisson's ratio of fabric in various extensions was measured. Analysis showed that the effect of both weft density and weave structure are significant with no combination effect on the Poisson's ratio. It was found that there is an exponential correlation between warp and weft crimp during fabric extension. For the worsted fabrics used in this research in all three fabric structures, fabrics with higher weft yarn density have higher value of Poisson's ratio. It was also concluded that for the fabrics with the same condition but only different in structures, this ratio is related to the structural firmness of fabric. In all three fabric structures the value of the Poisson's ratio were following the same pattern of twill 2/2, twill 3/1 and hopsack 2/2 from highest to lowest value. It was revealed that there is a high linear correlation between the crimp interchange ratio and Poisson's ratio.

Influence of Coating on the Poisson's Ratio of Woven Fabrics

2016 ◽  
Vol 827 ◽  
pp. 27-30 ◽  
Author(s):  
Diana Šimić Penava ◽  
Željko Penava ◽  
Marijana Tkalec
Keyword(s):  
Poisson’S Ratio ◽  
Experimental Testing ◽  
Tensile Force ◽  
Woven Fabrics ◽  
Poisson's Ratio ◽  
Basic Material ◽  
Relative Extension ◽  
Two Samples ◽  
Uniaxial Testing ◽  
Coated Fabrics

Coated fabrics have complex composite structure whose mechanical properties are considerably improved in relation with the initial basic material. They are obtained by applying a certain number of coatings to raw fabrics. In this paper the practical application of uniaxial testing of coated fabrics for determining its breaking properties and Poisson’s ratio is presented. Due to the anisotropy of woven and coated fabrics, Poisson's ratio changes over the fabric sample stretching. Experimental testing were carried out on two samples of plain weave cotton fabrics. The fabrics were tested before coating, and after one, two and three coatings. Samples are stretched with tensile force in the weft and warp direction, and based on different measured values of fabric stretching, warp and weft Poisson's ratio is calculated. The values of tensile force and relative extension of coated fabrics were measured, and breaking force values, elongation at break, contractions at break.

Tearing Strength Calculation Model of the Synthetic Leather Base

2010 ◽  
Vol 146-147 ◽  
pp. 546-550
Author(s):  
Cheng Qian
Keyword(s):  
Theoretical Model ◽  
Breaking Strength ◽  
Calculation Model ◽  
Woven Fabrics ◽  
Strength Calculation ◽  
Woven Fabric ◽  
Warp Yarn ◽  
Failure Mechanics ◽  
Synthetic Leather ◽  
Tearing Strength

The synthetic leather base is a composite, with the top and lower layers are nonwovens and the middle is woven fabrics. Firstly, the single rip tearing strength and drawing out resistances of the leather base were tested and tearing failure mechanics were analyzed. Then on the above basis, the single rip tearing strength calculation model of the synthetic leather base was built successfully. From theoretical model, main influencing factors are the weft and warp yarn breaking strength and the density of warp and weft yarns in the woven fabric, and also drawing out resistance of the leather base. Finally, experimental verification was made for the established model, which shows that theoretical values conform to the measured values well.

Variation of Poisson’s ratio of fabrics woven with helical composite auxetic weft yarns in relation to fabric structural parameters

2019 ◽  
Vol 50 (2) ◽  
pp. 149-169
Author(s):  
Asal Lolaki ◽  
Mohsen Shanbeh
Keyword(s):  
Poisson’S Ratio ◽  
Structural Parameters ◽  
Processing Technique ◽  
Poisson's Ratio ◽  
Image Processing Technique ◽  
Weft Yarn ◽  
Warp Yarn ◽  
Dimensional Changes ◽  
Weft Direction ◽  
Yarn Count

Auxetic textiles are defined as textiles with negative Poisson’s ratio. These textiles possess unique properties that render them suitable for special applications. This work aims to investigate the effect of fabric structural parameters such as thread densities, weave design and warp yarn count. Thus, 30 fabric samples were woven at 3 weft and 2 warp densities, respectively. Two warp counts and three weave designs of plain, basket 3/3 and weft-backed satin 6 were used. The samples were uniaxially loaded in weft direction and dimensional changes at various strains levels were evaluated. The evaluation was carried out using the image processing technique based on MATLAB software. The weft yarns used were found to exhibit auxetic behavior at the whole spectrum of the strain level used. The least weft yarn Poisson’s ratio was found to be −0.9. It was established that in general the fabric samples exhibit auxetic effect within the stated range of strain. Additionally, it was concluded that while fabric thread densities together with warp count influence the minimum fabric Poisson's ratio, auxetic behavior of the samples is not dependent on weave design alone. Rather, it was illustrated that the combined effect of weave design in association with stated structural parameters on auxetic feature cannot be ignored.

Characterization of the effect of fabric structure on the optical properties of woven fabrics

2019 ◽  
Vol 23 (1) ◽  
pp. 58-70
Author(s):  
Paniz Khosravani ◽  
Nazanin Ezazshahabi ◽  
Masoud Latifi
Keyword(s):  
Optical Properties ◽  
Structural Parameters ◽  
Human Perception ◽  
Comparative Judgment ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Content Type ◽  
Weave Structure ◽  
The Aesthetic ◽  
Fabric Surface

Purpose This paper aims to study the optical properties of woven fabrics. Design/methodology/approach The current study was carried out to objectively evaluate the luster of a group of woven fabrics with different weave structures and weft densities, with the aid of a goniophotometer. The results obtained from the objective luster measurement were validated by a set of pair comparison subjective tests using Thurstone’s law of comparative judgment. Findings The proper correlation with the R2 value of more than 0.96, between subjective and objective tests, confirmed the reliability and accordance of objective results with the human perception of luster. Statistical analysis of the luster results clarified that the effect of fabric structural parameters such as weave structure and weft density are significant at the confidence range of 95 per cent. The highest luster index was achieved for the twill 3/1 weave structure and the lowest luster belonged to the plain pattern. In addition, an increase in the density of the fabric leads to better luster. Moreover, it was concluded that the surface roughness affects the luster. A rise in the roughness value of the woven fabric causes reduction in its luster property. Originality/value Optical properties of woven fabrics, which are mainly attributed through the measurement of luster, are important for qualifying the aesthetic characteristics of the fabrics with various weave structures. Bearing in mind the influence of fabric surface properties on the aesthetic features of cloths, obtaining information in this field is a guide for selecting the suitable fabric for various end uses.

scholarly journals A Numerical Study of the Screening Effectiveness of Open Trenches for High-Speed Train-Induced Vibration

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Chih-hung Chiang ◽  
Pei-hsun Tsai
Keyword(s):  
Poisson’S Ratio ◽  
High Speed ◽  
Numerical Study ◽  
Cutoff Frequency ◽  
Poisson's Ratio ◽  
High Speed Train ◽  
High Speed Rail ◽  
Train Speed ◽  
Open Trench ◽  
Screening Effectiveness

This study used the 2D boundary element method in time domain to examine the screening effectiveness of open trenches on reducing vibration generated by a high-speed train. The parameters included configurations of the trench, train speed, the distance between the source and the trench, and the Poisson’s ratio of the soil. A reducing displacement level (in dB scale) was defined and used to evaluate the screening effectiveness of a wave barrier. The maximal reducing displacement level reached 25 dB when an open trench was used as a wave barrier. The depth of an open trench is a main influential parameter of screening effectiveness. The cutoff frequency of the displacement spectrum increases with decreasing trench depth. The maximal screening effectiveness occurs when the depth is 0.3-0.4 Rayleigh wavelength. Using an open trench as a wave barrier can reduce 10–25 dB of vibration amplitude at frequencies between 30 and 70 Hz. A considerable increase in screening effectiveness of the open trench was observed from 30 to 70 Hz, which matches the main frequencies of vibration induced by Taiwan High Speed Rail. The influence of trench width on screening effectiveness is nonsignificant except for frequencies from 30 to 40 Hz. Poisson’s ratio has various effects on the reduction of vibration at frequencies higher than 30 Hz.

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