Contents
Contributor contact details ix
Woodhead Publishing in Textiles xi
1 Introduction 1
P Schwartz, Auburn University, USA
1.1 Introduction: volume synopsis 1
1.2 Future trends 2
1.3 Sources of further information and advice 3
1.4 References 3
2 Characterization and measurement of textile fabric properties 4
A Causa and A Netravali, Cornell University, USA
2.1 Introduction 4
2.2 Tensile testing of woven fabrics 6
2.3 Stiffness (bending) testing of fabrics 8
2.4 Fabric shear – testing concepts 12
2.5 Tearing strength of fabrics 15
2.6 Test methods for fabric shear 17
2.7 Kawabata evaluation system (KES) 24
2.8 The FAST system: fabric assurance by simple testing 29
2.9 Detailed study of a fabric’s compressional property 29
2.10 Mechanisms of deformation of fabrics – summary 30
2.11 Fibrous assemblies as reinforcement of composite structures 30
2.12 Basic mechanics of laminates: application on testing 35
2.13 Three-dimensional fi brous assemblies for structural composites 42
2.14 Sources of further information and advice 43
2.15 Acknowledgements 45
2.16 References 45
3 Structure and mechanics of woven fabrics 48
J Hu and B Xin, The Hong Kong Polytechnic University,
Hong Kong
3.1 Introduction 48
3.2 Background 48
3.3 Structural properties of woven fabrics 49
3.4 Tensile properties of woven fabrics 56
3.5 Bending properties of woven fabrics 59
3.6 Shear properties of woven fabrics 62
3.7 Characterizing the mechanical behavior of woven fabrics based on image analysis 65
3.8 Modeling drape deformation of woven fabrics and garments 75
3.9 Conclusions 78
3.10 References and further reading 79
4 Structure and mechanics of knitted fabrics 84
M-A Bueno, Université de Haute Alsace, France
4.1 Introduction 84
4.2 Structural properties of knitted fabrics 85
4.3 Tensile properties of knitted fabrics 99
4.4 Bending properties of knitted fabrics 105
4.5 Shear properties of knitted fabrics 109
4.6 Shear-bending comparison 110
4.7 Modelling knitted fabric mechanics and simulation 111
4.8 Sources of further information and advice 112
4.9 References 113
5 Structure and mechanics of nonwovens 116
B Pourdeyhimi and B Maze, North Carolina State
University, USA
5.1 Introduction 116
5.2 Production processes 117
5.3 Web formation 117
5.4 Bonding 119
5.5 Structure property relationships 122
5.6 Failure mechanisms 130
5.7 Modeling nonwoven fabric mechanics: thermally bonded
nonwovens 136
5.8 References 139
6 Structure and mechanics of 2D and 3D textile
composites 141
C Pastore, Philadelphia University, USA and
Y Gowayed, Auburn University, USA
6.1 Introduction 141
6.2 Textile reinforcements for composites 141
6.3 Two-dimensional (2-D) fabrics 142
6.4 Three-dimensional (3-D) fabrics 151
6.5 Continuous stiffness/compliance variation methods 156
6.6 Bridging model 163
6.7 Numerical comparisons amongst models 165
6.8 Numerical models utilizing fi nite element analysis (FEA)
formulation 172
6.9 Non-unit cell considerations 176
6.10 References and further reading 182
7 Structure and mechanics of yarns 190
El-Mogahzy, Auburn University, USA
7.1 Introduction 190
7.2 Yarn classifi cation 191
7.3 Yarn structure 193
7.4 Theoretical treatments of yarn tensile strength 203
7.5 Strength-comfort-twist relationship 204
7.6 Practical aspects of yarn strength 208
7.7 Conclusions 211
7.8 References 211
8 Structure and mechanics of coated textile fabrics 213
S Adanur, Auburn University, USA
8.1 Introduction 213
8.2 Structural properties 213
8.3 Tensile and tear properties 221
8.4 Bending and flexibility properties 225
8.5 Shear and shear resistance properties 226
8.6 Modeling the mechanics of coated fabrics 228
8.7 Recycling of coated fabrics 230
8.8 Sources of further information and advice 238
8.9 References 239
Index 242
Introduction
P SCHWARTZ, Auburn University, USA
Abstract: The contents of the following volume are briefly outlined with a short description of each chapter. An attempt is made to predict future trends in the analysis of structural mechanics of fibrous assemblies. A non-exhaustive list of source materials is presented and relevant scientific meetings are identified.
Key words: structural mechanics, Kawabata Evaluation System (KES), three-dimensional fibrous assemblies, woven fabric mechanics, image analysis, knitted fabrics, structural composites, spun yarns, filament yarns, coated fabrics.
1.1 Introduction: volume synopsis
In the Preface to the classic book on structural mechanics (Hearle et al., 1969), Professor Stanley Backer noted the subject of structural mechanics was a significant part of the textile literature only during the ‘last twenty five years.’ Now, thirty-nine years later, the literature is replete with studies of the structural mechanics of fibrous assemblies but, as Professor Backer noted then, most of the work unfortunately is still to be found in the literature as individual manuscripts. This book is an attempt to collect in one place many of the developments in structural mechanics that have occurred since the 1969 publication and a companion volume (Hearle et al., 1980) that appeared eleven years later.
In Chapter 2, Professors Causa and Netravali, provide an exhaustive description of the characterization and measurement of fabric properties including traditional testing methods as well as the Kawabata Evaluation System (KES) and fabric assurance by simple testing (FAST). Also included is an overview of fully three-dimensional fibrous assemblies and of fi brous assembly reinforcement for composite materials.
Chapter 3, by Professors Hu and Xin, contains a thorough discussion of the structure and mechanics of woven fabrics. This chapter combines a rigorous analysis of the underlying modeling of mechanical properties with the emerging use of image analysis. Also included are experimental data that are used to validate the theoretical models.
The structure and mechanics of knitted fabrics are discussed by Professor Bueno in Chapter 4. Both weft and warp knitted fabrics are included. The chapter concludes with the modeling and simulation of knitted fabric properties.
Nonwoven fabrics have captured an increasing market share and most likely will continue to do so, especially in the health care product area. In Chapter 5, Professors Pourdeyhimi and Maze cover the methods of nonwovens manufacture, their structure-property relationships, failure mechanisms, and theoretical modeling.
In Chapter 6, Professors Pastore and Gowayed introduce two dimensional and three-dimensional fabrics for use in structural composites. They cover the structure and mechanics of woven, knitted, and braided structures and provide a comparison of the models’ prediction with experimental data.
Professor El-Mogahzy, in Chapter 7, presents both classical and more recent theories for the structure and mechanics of yarns, the building blocks of all but nonwoven fabrics. The mechanics of both spun and continuous fi lament yarns are covered.
Coated fabrics are the subject of Chapter 8. In this chapter Professor Adanur discusses the structure and manufacture of coated fabrics. This chapter also touches upon the important properties in coated fabrics, modeling, and recycling.