A macroscopic material model for woven fabrics based on mesoscopic sawtooth unit cell

2017 ◽  
Vol 180 ◽  
pp. 531-541 ◽  
Author(s):  
Ozan Erol ◽  
Brian M. Powers ◽  
Michael Keefe
Keyword(s):  
Material Model ◽  
Woven Fabrics ◽  
Unit Cell

A Non-Orthogonal Constitutive Material Model for Advanced Woven Fabrics Based on a Mesoscale Unit Cell

2016 ◽  
Author(s):  
Ozan Erol ◽  
Brian M. Powers ◽  
Michael Keefe
Keyword(s):  
Mechanical Behavior ◽  
Mechanical Response ◽  
Material Model ◽  
Shear Resistance ◽  
Woven Fabrics ◽  
Unit Cell ◽  
Uniaxial Tensile ◽  
Constitutive Material Model ◽  
Proposed Model ◽  
Constitutive Material

Advanced woven fabrics can provide a wide range of mechanical properties since the yarns can be arranged in different architectural patterns thus allowing the fabric structure to be tuned based on the specific needs. This adjustable nature makes them an attractive material choice for applications where versatility is highly desired. Hence, there is an increasing interest in woven fabrics in the recent years. They have been used in various applications such as deployable structures, protective garments, medical scaffolds and composites. With the increased interest, there is a need for efficient and accurate computational tools to investigate the mechanical behavior and deformation of woven fabrics for specific applications. Although there are several computational models in the literature that can model uniaxial and biaxial behavior of woven fabrics, there are not any commonly accepted material models for woven fabrics due to the complex interaction of trellising and deformation. Here, we propose an easy to implement constitutive material model based on a mesoscale unit cell of the woven fabrics. The proposed model utilizes the two prominent deformation mechanisms affecting the mechanical response at the mesoscale level: (1) Yarn stretching, and (2) shearing. These mesoscale mechanisms are mechanistically implemented within an unit cell by using truss and rotational springs to generate the mechanical response of the woven fabric. The yarns’ nonlinear mechanical behavior is modeled with non-linear trusses and assumed to be pin-jointed at the center of the unit cell. The truss elements are allowed to rotate at the pin-joint reproducing the yarns’ relative rotational motion during shearing. The fabric’s shear resistance involves two components: yarn-to-yarn relative rotation/sliding and yarn locking due to the yarn transverse compression. These components of the fabric shear resistance are modeled as a non-linear rotational spring located at the pin-joint which generates a moment resisting the shear deformation. The developed forces and moments from the trusses and rotational spring within the unit cell structure are then used to determine the continuum stress state of the material point. The material properties and parameters defined in the proposed model are easy to obtain from uniaxial tensile and shear tests on fabrics. To validate the material model, plain weave Kevlar KM2 fabric is modeled by replicating the standard uniaxial tensile and bias extension tests. The results obtained show that the material model provides a good description of the in-plane deformation and mechanical response.

Finite Element Modeling of Non-Orthogonal Loosely Woven Fabrics in Advanced Occupant Restraint Systems

2001 ◽  
Author(s):  
Romil R. Tanov ◽  
Marlin Brueggert
Keyword(s):  
Finite Element ◽  
Material Model ◽  
General Purpose ◽  
Woven Fabrics ◽  
Element Analysis ◽  
Correct Operation ◽  
Explicit Finite Element ◽  
Analysis Scheme ◽  
Occupant Restraint Systems ◽  
Protection Devices

Abstract The behavior of loosely woven fabrics differs significantly from other types of woven fabrics. Its unique characteristics have been successfully utilized for the correct operation of some recently developed occupant protection devices for the automotive and heavy machine and truck industry. However, this behavior cannot be efficiently modeled using the currently available material models within a finite element analysis scheme. Therefore, the aim of this work is to present the basics of a formulation of a material model for the analysis of loosely woven fabrics and its implementation in a general-purpose explicit finite element code. To assess the performance of the model, results from the simulation are presented and compared to real test data.

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.

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.

A meso-scale unit-cell based material model for the single-ply flexible-fabric armor

2009 ◽  
Vol 30 (9) ◽  
pp. 3690-3704 ◽  
Author(s):  
M. Grujicic ◽  
W.C. Bell ◽  
G. Arakere ◽  
T. He ◽  
B.A. Cheeseman
Keyword(s):  
Material Model ◽  
Unit Cell ◽  
Scale Unit ◽  
Meso Scale

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.

Comparison of two unit cell models and simulation results of high-pass woven fabrics

2018 ◽  
Vol 48 (6) ◽  
pp. 1097-1110 ◽  
Author(s):  
Fuwang Guan ◽  
Qincheng Su ◽  
Chenchen Yang ◽  
Chuyang Zhang ◽  
Yiping Qiu
Keyword(s):  
Research Work ◽  
Woven Fabrics ◽  
Unit Cell ◽  
Frequency Selective Surfaces ◽  
The Novel ◽  
Cell Models ◽  
Contrastive Analysis ◽  
Transmission Characteristics ◽  
One Dimensional ◽  
High Pass

Based on the research work of traditional electromagnetic shielding fabrics and frequency selective surfaces, the novel high-pass woven fabrics were proposed. Two different unit cell models were built and compared, and a series of design samples were further simulated based on the models. Through contrastive analysis and discussion of the simulated results, the validity of model 1 was verified and the influence rules of various parameters were explored. Compared with model 1, model 2 was more precise containing the textile information, like yarn crimp, fabric porosity and thickness, but model 1 could substitute model 2 to predict the transmission characteristics to some extent. The ratio of conductive and dielectric yarns affected the high-pass characteristics greatly, and different from two-dimensional high-pass woven fabrics, one-dimensional high-pass woven fabrics showed distinct polarization selective characteristics. Yarn electromagnetic parameters and fabric parameters could also exert an effect on the S21 curves in different degrees, which could help designers choose materials and determine the fabric parameters effectively. The modelling and simulation work could provide guidance to the development of actual high-pass woven fabrics.

Sign in / Sign up

Export Citation Format

Share Document