Phantom-Element Technique for Periodic Deformation Analysis of Plain Fabrics Using LS-DYNA

2018 ◽  
Author(s):  
Hikaru Miyaki ◽  
Atsushi Sakuma
Keyword(s):  
Initial Stress ◽  
Periodic Structures ◽  
Woven Fabrics ◽  
Unit Cell ◽  
Woven Fabric ◽  
Initial Stresses ◽  
Deformation Analysis ◽  
Initial State ◽  
Periodic Deformation ◽  
Periodic Analysis

Unit-cell modelling is one of the useful methods to analyze deformation in periodic structures like honeycombs, perforated boards, and woven fabrics. The initial state of the structures is considered to be stress-free in ordinal deformation analysis, but in actual practice, the analysis is difficult, because initial stresses like assembly stress and residual stress need to be considered, as they are known to affect the results. In this study, a technique of taking into account the initial-stress state in woven fabrics is discussed, which has resulted in the establishment of a precise design method for textiles. LS-DYNA, which is a general-purpose finite element (FE) software, has been utilized to simulate the complex deformations in woven fabrics. In this software, a function of the global constraint on boundary conditions facilitates the analysis of periodic structures, but causes difficulties in computing the initial stress states in woven fabrics, as the conditions of mechanical equilibrium have to be satisfied in the governing equations. In particular, duplicated definitions of forced displacement and periodic deformation make the computation impossible, hence, a phantom-element has been introduced to ease the FE analysis by defining these quantities. A unit-cell of the woven fabric is identified and the initial states in stressed conditions can be estimated for periodic structures of plain-woven fabrics by a periodic-analysis technique of LS-DYNA coupled with the phantom-element, which yields a weaving motion of the yarn in plain-woven fabrics.

Diagram Design of Weaving Process for Touch-Feel Estimation of Plain-Woven Fabrics by Finite Element Method

2020 ◽  
Author(s):  
Hikaru Miyaki ◽  
Atsushi Sakuma
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Initial Stress ◽  
Woven Fabrics ◽  
Unit Cell ◽  
Open Set ◽  
Digital Evaluation ◽  
Adopted Model ◽  
Woven Structure ◽  
Element Method

Abstract Digital evaluation of touch-feel in textiles is useful to design fundamental functions of clothing. Here, it is necessary to design textiles for a detailed evaluation of the sensitivity in human’s feelings to consider the life-style creation in various aspects. Then, the objective of this paper is to propose a design method for plain-woven fabrics by touch-feel estimation considering the weaving process with the constitutive relations of yarn. Here, a diagram for control weaving is defined by the diameter of the yarn and displacement quantity of the weaving and the cramping by defining the theoretical thickness. For the effective design to consider various processes, unit-cell of plain-woven structures are fundamentally classified as open set models and closed set models. One of the unit-cell models in the finite element method (FEM) for the plain-woven structure is adopted because the adopted model can consider initial-stress distribution in the weaving process. For touch-feel estimation, an analysis model is constructed by warp, weft, and plungers that cramps the woven structure. A series of diagrams to compress with plungers is shown after constructing a plain-woven structure. As for analyzing the weaving process and the touch-feel estimation in one model, realization of the effective engineering is enabled. This procedure yields that the relationship between the displacement and simulation time suggests for consideration of initial-stress.

scholarly journals Remeshing procedure for discrete membrane finite element: application to woven composite forming

2012 ◽  
Author(s):  
Abel Cherouata ◽  
Laurence Moreau ◽  
Rezak Ayad ◽  
Tarak Ben Zineb
Keyword(s):  
Finite Element ◽  
Composite Materials ◽  
Finite Elements ◽  
Woven Fabrics ◽  
Unit Cell ◽  
Woven Fabric ◽  
Complex Structures ◽  
Woven Composite ◽  
Quadrilateral Element ◽  
Composite Forming

Pre-impregnated woven fabric is an increasingly important component as the reinforcement phase of composite materials for many mechanical structures (automotive and aerospace). Modelling woven fabrics is difficult due, in particular, to the need to simulate the response both at the scale of the entire fabric and at the meso-level, the scale of the fibre that composes the weave. Here, we present new finite element for the simulation of the 3D, preimpregnated woven fabric preform. Continuum-level modelling technique that, through the use of an appropriate bi-component unit cell (fiber rotation quadrilateral element connected to truss elements), captures the deformation of the mesostructure of the fabric without explicitly modelling every fibre. Simulations of the experiments demonstrate that the finite elements are capable of efficiently simulating large, complex structures and forming processes.

Mechanical Behaviors of Woven Fabrics

2004 ◽  
Author(s):  
Huiyu Sun ◽  
Ning Pan
Keyword(s):  
Mechanical Model ◽  
Structural Parameters ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Research Progress ◽  
Deformation Analysis ◽  
Shear Moduli ◽  
Slip Region ◽  
Poisson's Ratios ◽  
Poisson’S Ratios

This paper introducing some recent research progress consists of two parts: the shear deformation analysis and Poisson’s ratios for woven fabrics. The analytical methods of the shear moduli and Poisson’s ratios for woven fabrics will enable more rigorous studies on such important issues of fabric bending and draping behaviors. A new mechanical model is proposed in this paper to evaluate the shearing properties for woven fabrics during the initial slip region. Compared to the existing mechanical models for fabric shear, this model involves not only bending but also torsion of curved yarns. Analytical results show that this model provides better agreement with the experiments for both the initial shear modulus and the slipping angle than the existing models. Furthermore, another mechanical model for a woven fabric made of extensible yarns is developed to calculate the fabric Poisson’s ratios. Theoretical results are compared with the available experimental data. A thorough examination on the influences of various mechanical properties of yarns and structural parameters of fabrics on the Poisson’s ratios of a woven fabric is given.

Progressive failure prediction of woven fabric composites using a multi-scale approach

2016 ◽  
Vol 27 (1) ◽  
pp. 97-119 ◽  
Author(s):  
Lei Xu ◽  
YuanChen Huang ◽  
Chao Zhao ◽  
Sung Kyu Ha
Keyword(s):  
Progressive Failure ◽  
Woven Fabrics ◽  
Unit Cell ◽  
Woven Fabric ◽  
Micro Scale ◽  
Multi Scale ◽  
Woven Fabric Composites ◽  
Representative Unit Cell ◽  
Fabric Composites ◽  
Meso Scale

Finite element representative unit cell models are established for the study of progressive failure of woven fabrics: plain weave, twill weave, and satin weave. A multi-scale approach ranging from the meso-scale to micro-scale regime is used, providing the failure observation inside the constituents. The constituent stresses of the fiber and matrix in the warp and fill tows of the woven fabric unit cell are calculated using micromechanics. Correlations between meso-scale tow stresses and micro-scale constituent stresses are established by using stress amplification factors. After calculating micro-scale stresses, the micromechanics of failure damage model is employed to determine the progressive damage statuses in each constituent of woven fabric composites. For the matrix of tows, a volume-averaging homogenization method is utilized to eliminate damage localization by smearing local damages over the whole matrix region of the unit cell. Subsequently, the ultimate strength is predicted for woven composites with different tow architectures. The prediction results are compared with the experimental values, and good agreement is observed.

On the Effect of Uncertainty Factors on Mechanical Behavior of Woven Fabric Composites at Meso-Level

2009 ◽  
Author(s):  
Mojtaba Komeili ◽  
Abbas S. Milani
Keyword(s):  
Computer Experiments ◽  
Woven Fabrics ◽  
Unit Cell ◽  
Woven Fabric ◽  
Meso Level ◽  
Woven Fabric Composites ◽  
Fabric Composites ◽  
Geometrical Defects ◽  
Noise Factors ◽  
Fiber Misalignment

Unit cell modeling of woven fabric composites at meso-level has been advantageous in finding equivalent mechanical properties of different weave architectures without performing physical experiments on each new fabric. The obtained properties, in turn, can be used in the macro-level modeling and simulation of large composite structures. Models used for this purpose, however, often consider a perfect description of unit cells, while in practice fabrics are not always fabricated under ideal conditions and flaws like fiber misalignment, material and/or geometrical defects are present. A benchmark work covering effects of this kind on the mesoscopic behavior of woven fabrics is underway. The aim of this paper is to present a statistical way to approach the problem by studying the main effects of such uncertainty/noise factors along with their levels of significance. Namely, a one-factor-at-a-time screening method is selected to identify the effect of (1) fiber misalignment, (2) fiber modulus variation, (3) geometrical flaws in yarn section, (4) unpredictable friction between weft and warp yarns. Computer experiments are done using FE modeling of a plain weave unit cell under the uniaxial, equibiaxial, and trellising (shear) modes. A parameter sensitivity analysis is conducted to identify the most significant factors and the extent to which each can independently contribute to the variation of load-displacement curves (i.e., testing data non-repeatabilities).

scholarly journals Use of Extended Cover Factor Theory in UV Protection of Woven Fabric

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1188
Author(s):  
Klara Kostajnšek ◽  
Krste Dimitrovski
Keyword(s):  
Woven Fabrics ◽  
Uv Protection ◽  
Woven Fabric ◽  
Simplified Model ◽  
Light Penetration ◽  
Protective Properties ◽  
Cover Factor ◽  
Coefficient Of Reflection ◽  
Uv Protective Properties

The paper presents an extension of existed cover factor theory more suitable for the evaluation of light penetration through a net woven fabrics structure. It also introduces a new simplified model of predicting the ultraviolet (UV) protective properties of woven fabrics assuming that the coefficient of reflection (KR), transmission (KT), and absorption (KA) of constitutive yarns are known. Since usually they are not, the procedure of preparation of simulation of proper woven fabric samples without interlacing and with known constructional parameters is also presented. The procedure finishes with a fast and cheap detection of missed coefficient for any type of yarns. There are differences between theoretical and measured results, which are not particularly significant in regard to the purpose and demands of investigation.

Fundamentals of generalized rigidity matrices for multi-layered media

1983 ◽  
Vol 73 (3) ◽  
pp. 749-763
Author(s):  
Maurice A. Biot
Keyword(s):  
Plane Strain ◽  
Initial Stress ◽  
Three Dimensional ◽  
Layered Media ◽  
Mathematical Structure ◽  
Irreversible Thermodynamics ◽  
Initial Stresses ◽  
General Context ◽  
Viscoelastic Media ◽  
Linear Irreversible Thermodynamics

abstract Rigidity matrices for multi-layered media are derived for isotropic and orthotropic layers by a simple direct procedure which brings to light their fundamental mathematical structure. The method was introduced many years ago by the author in the more general context of dynamics and stability of multi-layers under initial stress. Other earlier results are also briefly recalled such as the derivation of three-dimensional solutions from plane strain modes, the effect of initial stresses, gravity, and couple stresses for thinly laminated layers. The extension of the same mathematical structure and symmetry to viscoelastic media is valid as a consequence of fundamental principles in linear irreversible thermodynamics.

Prediction of Permeability Tensor for Plain Woven Fabric by Using Control Volume Finite Element Method

2003 ◽  
Vol 11 (6) ◽  
pp. 465-476 ◽  
Author(s):  
Y. S. Song ◽  
K. Chung ◽  
T. J. Kang ◽  
J. R. Youn
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Control Volume ◽  
Three Dimensional ◽  
Woven Fabrics ◽  
Permeability Tensor ◽  
Woven Fabric ◽  
Stacking Order ◽  
Control Volume Finite Element ◽  
Element Method

The complete prediction of the second order permeability tensor for a three dimensional multi-axial preform is critical if we are to model and design the manufacturing process for composites by considering resin flow through a multi-axial fiber structure. In this study, the in-plane and transverse permeabilities for a woven fabric were predicted numerically by the coupled flow model, which combines microscopic and macroscopic flows. The microscopic and macroscopic flows were calculated by using 3-D CVFEM(control volume finite element method) for micro and macro unit cells. To avoid a checkerboard pressure field and improve the efficiency of numerical computation, a new interpolation function for velocity is proposed on the basis of analytical solutions. The permeability of a plain woven fabric was measured by means of an unidirectional flow experiment and compared with the permeability calculated numerically. Reverse and simple stacking of plain woven fabrics were taken into account and the relationship between the permeability and the structures of the preform such as the fiber volume fraction and stacking order is identified. Unlike other studies, the current study was based on a more realistic three dimensional unit cell. It was observed that in-plane flow is more dominant than transverse flow within the woven perform, and the effect of the stacking order of a multi-layered preform was negligible.

Manufacturing Process and Property Evaluation of Functional Composite Yarn-Dyed Woven Fabrics Made from Bamboo Charcoal/Stainless Steel and TPU

2008 ◽  
Vol 55-57 ◽  
pp. 413-416 ◽  
Author(s):  
C.I. Huang ◽  
C.I. Su ◽  
Ching Wen Lou ◽  
Wen Hao Hsing ◽  
Jia Horng Lin
Keyword(s):  
Stainless Steel ◽  
Manufacturing Process ◽  
Far Infrared ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Weft Yarn ◽  
Bamboo Charcoal ◽  
Functional Composite ◽  
Composite Yarn ◽  
Composite Fabrics

Recently, development of technology increases human life quality and gradually raises the value of health protection in human’s concept. Bamboo has multi-functional including far infrared radiation, deodorization and anion generation. Therefore, bamboo charcoal has been widely used in textile industry. Moreover, development of technology also increased the electromagnetic hazard in human’s daily life. This study aims to develop a manufacturing process of functional composite yarn-dyed woven fabrics. In the manufacturing process, the materials included pure cotton yarn, stainless steel fiber(called metallic yarn) and viscose rayon yarn containing bamboo charcoal (called bamboo charcoal yarn) were used for making the bamboo charcoal/stainless steel composite woven fabric. The composite woven fabrics were woven by using same warp yarn and two kinds of weft yarn that contained bamboo charcoal and stainless steel. The composite fabrics had two different structures. Those fabrics were changed the order of bamboo charcoal yarn and metallic yarn. The ratios of weft yarn were 1 end of bamboo charcoal yarn to 1 end of metallic yarn and 3 ends of bamboo charcoal yarn to 1 end of metallic yarn. Furthermore, the fabrication of composite fabrics that included plain, 2/2 twill and dobby were changed. The composite woven fabrics were finished and laminated by TPU film to enhance the waterproof and vapor permeable functions. The laminated composite fabrics were evaluated by far-infrared coefficient, anion generation rate, water vapor permeability, water resistance, surface electric resistance and electromagnetic shelter property to obtained optimal manufacturing process.

scholarly journals Application of Natural Dyes and Sodium Alginate From Sargassum Sp. Sea weed In Coloring Bima Woven Fabric

2020 ◽  
Vol 36 (05) ◽  
pp. 964-967
Author(s):  
Agrippina Wiraningtyan ◽  
Ruslan Ruslan ◽  
Putri Ayu Mutmainnah ◽  
Magfirah Perkasa
Keyword(s):  
Surface Structure ◽  
Sodium Alginate ◽  
Morphological Analysis ◽  
Woven Fabrics ◽  
Natural Dyes ◽  
Woven Fabric ◽  
Dyeing Process ◽  
Wave Numbers ◽  
Absorption Pattern ◽  
Before And After

This study aims to extract dye and alginate from seaweed Sargassum sp. as a dye paste in the coloring of Bima woven fabric. The concentration of sodium alginate used was 0%; 1%; 3% and 5%. The results showed that the absorbance value of the dye extract from seaweed Sargassum sp at maximum λ = 203 nm obtained A = 3.899. The effect of variations in the concentration of sodium alginate in the dye paste was determined by comparing the FTIR absorption pattern of Bima woven fabrics. Based on the FTIR absorption pattern data, it was found that a mixture of dye and sodium alginate of 3% had a stronger intensity, namely the wave numbers 3448.72 cm-1 and 1635 cm-1; 2900.94 cm-1; 2337.72 cm-1; 1381.03 cm-1 and 1064.71 cm-1. The results of the morphological analysis showed significant differences in surface structure on Bima woven fabrics before and after the dyeing process.

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