Cylindrical Orthotropic Thermal Conductivity of Spiral Woven Composites Part I: Modelling of a Spiral Woven Structure

This is the first a series of papers on the cylindrical orthotropic thermal conductivity of spiral woven composites. The geometric characteristics of spiral woven composites are modelled in the present study. A single layer of spiral woven fabric is considered as a fundamental structure and used to develop representative models, including round disc and polygon ones. In these representative models, crimps, cross-sections, and radial and circumferential arrangements of yarns are illustrated by cosine and arc yarn shape functions. A trapezoidal unit cell extracted from a polygon model will provide the next project in the series, with basic geometric parameters to develop thermal models for determining the thermal conductivities of spiral woven composites.

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Determination of the pore size of woven structures through image analysis

Open Engineering ◽

10.2478/s13531-011-0045-2 ◽

2012 ◽

Vol 2 (1) ◽

Cited By ~ 5

Author(s):

R. Angelova

Keyword(s):

Pore Size ◽

Single Layer ◽

Woven Fabric ◽

Virtual Model ◽

Experimental Procedure ◽

Porosity And Permeability ◽

Woven Structures ◽

Woven Structure ◽

Non Destructive

AbstractThe paper presents an experimental procedure developed for determination of the pore size, shape and distribution in a single layer woven fabric, for the construction of a virtual model to be incorporated in a future CFD software package. The procedure is based on non-destructive observation and analysis of woven samples. 14 different samples of gray fabrics of 100 % cotton in plain and twill weaves are investigated. The results obtained allow the creation of reality more realistic virtual model of the woven structure, and theoretical investigation of its porosity and permeability through computer simulation.

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Three dimensional simulation of air permeability of single layer woven structures

Open Engineering ◽

10.2478/s13531-011-0042-5 ◽

2011 ◽

Vol 1 (4) ◽

Cited By ~ 2

Author(s):

Radostina Angelova ◽

Peter Stankov ◽

Iskra Simova ◽

Idoya Aragon

Keyword(s):

Cross Sections ◽

Three Dimensional ◽

Single Layer ◽

Woven Fabrics ◽

Transverse Permeability ◽

Woven Structures ◽

Dimensional Simulation ◽

Jet Cross Sections ◽

Woven Structure

AbstractThe paper deals with a CFD based study of the transverse permeability of a textile woven structure. The reported numerical investigation is preconditioned by both previous experimental and CFD study on jet systems. It is also based on detailed experimental investigation of the porous structure of single layer woven fabrics, made of staple fiber yarns. The flow in through-thickness direction of the woven structures is presented as jet systems, issuing from set of orifices. Two different types of jet system (3×3 jets and 5×5 jets) with two types of jet cross sections (square and circular), corresponding to two different woven structures, are simulated. An analysis is made in terms of the structure of the woven fabrics (area and shape of the interstices between the threads), the parameters of the flow passing through the textile (velocity profiles and velocity fields through isosurfaces), the role of the type of the jet systems, representing the flow and the influence of the shape of the interstices between the threads on the flow pattern. It was found that the applied approach could be effectively used for studying of the transverse permeability of the woven fabrics.

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Finite element analysis of mechanical properties of woven composites through a micromechanics model

Science and Engineering of Composite Materials ◽

10.1515/secm-2014-0266 ◽

2017 ◽

Vol 24 (1) ◽

pp. 87-99 ◽

Cited By ~ 1

Author(s):

Haris A. Khan ◽

Abid Hassan ◽

M.B. Saeed ◽

Farrukh Mazhar ◽

Imran A. Chaudhary

Keyword(s):

Mechanical Properties ◽

Finite Element Analysis ◽

Finite Element ◽

Geometric Parameters ◽

Woven Fabric ◽

Woven Composites ◽

Element Analysis ◽

Micromechanics Model ◽

Plain Weave ◽

Fabric Composite

AbstractIn a woven fabric composite, arrangement and behavior of the fibers contained in the yarn and the yarns themselves lead to an intricate deformation mechanism. The current research, therefore, intends to propose a simplified mathematical micromechanics model for calculating mechanical properties of the plain weave composite using finite element analysis (FEA). A repetitive volume element (RVE) cell approach has been adopted for properties evaluation of plain weave composites. The FEA allows the modeling and portrayal of fabrics by taking into account various geometric parameters such as the yarn undulation, the probability of existence of consonances in a unit cell and interaction between warp and fill tows. These factors help in generating a mesh close to the actual fabric/composite. Additionally, a technique to represent the internal layout of composite structure employing actual dimensions of yarn geometry using conventional measurement devices, rather than using the demanding method of obtaining measurements from photomicrographs of sectioned laminates, is also proposed. The geometric symmetries as reported in the available literature were also incorporated during the model formulation. The theory of comparative displacements was then used to construe these symmetries into appropriate mechanical terms. Consequently, this leads to the formulation of boundary conditions for the RVE. The proposed finite element micromechanics model is different from the existing models in a way that it defines the yarn cross-sectional path based upon computational fluid dynamics technique rather than conventionally obtained photomicrographic results or the proposed sinusoidal paths by various researchers. Experiments were then performed on the laminates used for obtaining the geometric parameters with the aim of supporting the validity of the suggested model. The results of computational analysis were found to be in good agreement with the outcomes of experimental investigation.

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Design, Development, and Characterization of Advanced Textile Structural Hollow Composites

Polymers ◽

10.3390/polym13203535 ◽

2021 ◽

Vol 13 (20) ◽

pp. 3535

Author(s):

Zunjarrao Kamble ◽

Rajesh Kumar Mishra ◽

Bijoya Kumar Behera ◽

Martin Tichý ◽

Viktor Kolář ◽

...

Keyword(s):

Single Layer ◽

Woven Fabric ◽

Woven Composites ◽

Constant Thickness ◽

Design Development ◽

Resin Infusion ◽

Spacer Fabric ◽

The Impact ◽

Infusion Technique

The research is focused on the design and development of woven textile-based structural hollow composites. E-Glass and high tenacity polyester multifilament yarns were used to produce various woven constructions. Yarn produced from cotton shoddy (fibers extracted from waste textiles) was used to develop hybrid preforms. In this study, unidirectional (UD), two-dimensional (2D), and three-dimensional (3D) fabric preforms were designed and developed. Further, 3D woven spacer fabric preforms with single-layer woven cross-links having four different geometrical shapes were produced. The performance of the woven cross-linked spacer structure was compared with the sandwich structure connected with the core pile yarns (SPY). Furthermore, three different types of cotton shoddy yarn-based fabric structures were developed. The first is unidirectional (UD), the second is 2D all-waste cotton fabric, and the third is a 2D hybrid fabric with waste cotton yarn in the warp and glass multifilament yarn in the weft. The UD, 2D, and 3D woven fabric-reinforced composites were produced using the vacuum-assisted resin infusion technique. The spacer woven structures were converted to composites by inserting wooden blocks with an appropriate size and wrapped with a Teflon sheet into the hollow space before resin application. A vacuum-assisted resin infusion technique was used to produce spacer woven composites. While changing the reinforcement from chopped fibers to 3D fabric, its modulus and ductility increase substantially. It was established that the number of crossover points in the weave structures offered excellent association with the impact energy absorption and formability behavior, which are important for many applications including automobiles, wind energy, marine and aerospace. Mechanical characterization of honeycomb composites with different cell sizes, opening angles and wall lengths revealed that the specific compression energy is higher for regular honeycomb structures with smaller cell sizes and a higher number of layers, keeping constant thickness.

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Using Textile Topography to Analyze X-Ray CT Data of Composite Microstructure

10.1115/imece2001/htd-24360 ◽

2001 ◽

Author(s):

Richard S. Parnas ◽

Martine Wevers ◽

Ignaas Verpoest

Keyword(s):

Cross Sections ◽

Signal To Noise Ratio ◽

Single Layer ◽

Image Data ◽

Structural Features ◽

Woven Fabric ◽

Micro Computed Tomography ◽

X Ray ◽

3 Dimensional ◽

Ct Data

Abstract The 3-dimensional yam architecture in a 2-dimensional woven fabric reinforced composite is nonuniform. Many structural features appear that are not obvious from consideration only of the yarn architecture in the single layer textile fabric. A complete set of 3-dimensional image data was acquired for a representative volume of the composite using X-ray micro-computed tomography. Extensive image analysis was, however, necessary to reveal the yarn architecture due to relatively low signal-to-noise ratio and contrast levels relative to optical microscopy of polished cross sections.

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An experimental study of the motion of ice past obstacles by the process of regelation

Journal of Glaciology ◽

10.1017/s0022143000030744 ◽

1976 ◽

Vol 17 (75) ◽

pp. 79-98 ◽

Cited By ~ 14

Author(s):

E. M. Morris

Keyword(s):

Thermal Conductivity ◽

Experimental Study ◽

Cross Sections ◽

Transition Point ◽

Water Layer ◽

Single Object ◽

Two Systems ◽

Basal Sliding

AbstractThe results of regelation experiments, in which a single object is pulled through ice, cannot be applied directly to the problem of basal sliding in glaciers because the two systems have different geometries. When the force applied to a single object is small, impurities trapped in the regelation water-layer around the object inhibit the regelation process. At larger forces, above the Drake-Shreve transition point, impurities are shed in a trace behind the object. However, when ice moves over a series of obstacles a trace may exist above and below the transition point. The regelation velocity below the transition point is not reduced by the effect of trapped impurities. In an experiment in which brass cylingerrs of various cross-sections rotate in ice, the ratio between the expected regelation velocity, calculated using the basal-sliding theory of Nye, and the measured regelation velocity is 8±2, both above and below the transition point. The same ratio has been obtained by other workers with wires of similar thermal conductivity above the transition point. Measurements of température differences indicate that supercooling cannot be the main source of the unexpectedly low regelation velocities above the transition point.

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Morphological and phytochemical analysis of leaves and stems of Tetrapterys multiglandulosa CAV.

Australian Journal of Crop Science ◽

10.21475/ajcs.20.14.06.p2284 ◽

2020 ◽

pp. 959-964

Author(s):

Gilberto Gonçalves Facco ◽

Eloty Justina Schleder ◽

Natalia Yoshioka de Vidis ◽

Maristela Halverson ◽

Rosemary Matias ◽

...

Keyword(s):

Cross Sections ◽

Clinical Signs ◽

Single Layer ◽

Anatomical Study ◽

Phytochemical Analysis ◽

Native Plant ◽

Circular Section ◽

Vegetative Organs ◽

Ethanol Extracts ◽

Columnar Cells

This study aimed to carry out morphoanatomical, histochemical and phytochemical analysis of leaves and stems of Tetrapterys multiglandulosa Cav. (Malpighiaceae), a native plant responsible for abortion and sudden death in beef cattle. Plant specimens underwent anatomical study, in which leaves and stems were dried and ground with aqueous and ethanol extracts subjected to histochemical and phytochemical analysis. Anatomical observation of vegetative organs detected the presence of simple columnar cells in the adaxial epidermis, palisade mesophyll, parenchyma with a layer of cells and paracitic type stomata. Stem cross-sections presented circular section, single layer (uniseriate) epidermis with thick cuticle and Malpighi’s trichomes, the phelogen was in differentiation. The cortex showed angular collenchyma, parenchyma with exogenous channels and druse shaped calcium oxalate crystals. Phytochemical tests of aqueous and ethanol extracts of leaves and stems indicated the presence of phenolic compounds, tannins, flavonoids, saponins, alkaloids and cardiotonic heterosides. Potentially phytotoxic secondary metabolites evidenced in the leaves and stems, including saponins and cardiotonic heterosides were correlated with clinical signs observed in intoxicated animals.

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