Contents
Contributor contact details ix
Introduction xiii
A C LONG, University of Nottingham, UK
1 Manufacturing and internal geometry of textiles 1
S LOMOV, I VERPOEST, Katholieke Universiteit Leuven, Belgium and F ROBITAILLE, University of Ottawa, Canada
1.1 Hierarchy of textile materials 1
1.2 Textile yarns 2
1.3 Woven fabrics 10
1.4 Braided fabrics 27
1.5 Multiaxial multiply non-crimp fabrics 35
1.6 Modelling of internal geometry of textile preforms 47
1.7 References 60
2 Mechanical analysis of textiles 62
A C LONG, University of Nottingham, UK, P BOISSE, INSA Lyon,
France and F ROBITAILLE, University of Ottawa, Canada
2.1 Introduction 62
2.2 In-plane shear 63
2.3 Biaxial in-plane tension 73
2.4 Compaction 88
2.5 References 107
3 Rheological behaviour of pre-impregnated textile composites 110
P HARRISON and M CLIFFORD, University of Nottingham, UK
3.1 Introduction 110
3.2 Deformation mechanisms 111
3.3 Review of constitutive modelling work 116
3.4 Characterisation methods 129
3.5 Forming evaluation methods 137
3.6 Summary 142
3.7 Acknowledgements 142
3.8 References 143
4 Forming textile composites 149
W-R YU, Seoul National University, Korea and A C LONG,
University of Nottingham, UK
4.1 Introduction 149
4.2 Mapping approaches 149
4.3 Constitutive modelling approach 155
4.4 Concluding remarks and future direction 175
4.5 Acknowledgements 178
4.6 References 178
5 Manufacturing with thermosets 181
J DOMINY, Carbon Concepts Limited, UK, C RUDD, University of
Nottingham, UK
5.1 Introduction 181
5.2 Pre-impregnated composites 181
5.3 Liquid moulding of textile composites 187
5.4 References 196
6 Composites manufacturing – thermoplastics 197
M D WAKEMAN and J-A E. MÅNSON, École Polytechnique Fédérale
de Lausanne (EPFL), Switzerland
6.1 Introduction 197
6.2 Consolidation of thermoplastic composites 198
6.3 Textile thermoplastic composite material forms 205
6.4 Processing routes 217
6.5 Novel thermoplastic composite manufacturing routes 233
6.6 Conclusions 236
6.7 Acknowledgements 236
6.8 References 237
7 Modeling, optimization and control of resin flow during manufacturing of textile composites with
liquid molding 242
A GOKCE and S G ADVANI, University of Delaware, USA
7.1 Liquid composite molding processes 242
7.2 Flow through porous media 244
7.3 Liquid injection molding simulation 247
7.4 Gate location optimization 254
7.5 Disturbances in the mold filling process 259
7.6 Active control 268
7.7 Passive control 274
7.8 Conclusion 285
7.9 Outlook 286
7.10 Acknowledgements 288
7.11 References 288
8 Mechanical properties of textile composites 292
I A JONES, University of Nottingham, UK and A K PICKETT, Cranfield University, UK
8.1 Introduction 292
8.2 Elastic behaviour 292
8.3 Failure and impact behaviour 312
8.4 References 327
9 Flammability and fire resistance of composites 330
A R HORROCKS and B K KANDOLA, University of Bolton, UK
9.1 Introduction 330
9.2 Constituents – their physical, chemical, mechanical and flammability properties 332
9.3 Flammability of composite structures 346
9.4 Methods of imparting flame retardancy to composites 349
9.5 Conclusions 359
9.6 References 360
10 Cost analysis 364
M D WAKEMAN and J-A E MÅNSON, École Polytechnique Fédérale
de Lausanne (EPFL), Switzerland
10.1 Introduction 364
10.2 Cost estimation methodologies 366
10.3 Cost build-up in textile composite applications 374
10.4 Case study 1: thermoplastic composite stamping 382
10.5 Case study 2: composites for the Airbus family 396
10.6 Conclusions 402
10.7 Acknowledgements 402
10.8 References 402
11 Aerospace applications 405
J LOWE, Tenex Fibres GmbH, Germany
11.1 Introduction 405
11.2 Developments in woven fabric applications using standard prepreg processing 406
11.3 Carbon fibre multiaxial fabric developments 408
11.4 Improvement in standard fabric technology for non-prepreg processing applications 416
11.5 Braided materials 417
11.6 Tailored fibre placement 418
11.7 Preforming 419
11.8 Repair of fabric components 423
12 Applications of textile composites in the construction industry 424
J CHILTON, University of Lincoln, UK and R VELASCO,
University of Nottingham, UK
12.1 Introduction 424
12.2 Fibre reinforced polymers 424
12.3 Membrane structures 426
12.4 Case studies 429
12.5 Future developments 431
12.6 References 435
13 Textile reinforced composites in medicine 436
J G ELLIS, Ellis Developments Limited, UK
13.1 Splinting material 436
13.2 Walking support frame 438
13.3 Bone plates 439
13.4 General application 441
13.5 Living composites 442
14 Textile composites in sports products 444
K VAN DE VELDE, Ghent University, Belgium
14.1 Introduction 444
14.2 Materials 445
14.3 Design 447
14.4 Production technology 449
14.5 Applications 450
14.6 Conclusion 456
14.7 Acknowledgement 456
14.8 References 456
Glossary 458
Introduction
A C L O N G, University of Nottingham, UK
Textile composites are composed of textile reinforcements combined with a binding matrix (usually polymeric). This describes a large family of materials used for load-bearing applications within a number of industrial sectors. The term textile is used here to describe an interlaced structure consisting of yarns, although it also applies to fibres, filaments and yarns, and most products derived from them. Textile manufacturing processes have been developed over hundreds or even thousands of years. Modern machinery for processes such as weaving, knitting and braiding operates under automated control, and is capable of delivering high-quality materials at production rates of up to several hundreds of kilograms per hour. Some of these processes (notably braiding) can produce reinforcements directly in the shape of the final component. Hence such materials can provide an extremely attractive reinforcement medium for polymer composites.
Textile composites are attracting growing interest from both the academic community and from industry. This family of materials, at the centre of the cost and performance spectra, offers significant opportunities for new applications of polymer composites. Although the reasons for adopting a particular material can be various and complex, the primary driver for the use of textile reinforcements is undoubtedly cost. Textiles can be produced in large quantities at reasonable cost using modern, automated manufacturing techniques. While direct use of fibres or yarns might be cheaper in terms of materials costs, such materials are difficult to handle and to form into complex component shapes. Textile-based materials offer a good balance in terms of the cost of raw materials and ease of manufacture.
Target application areas for textile composites are primarily within the aerospace, marine, defence, land transportation, construction and power generation sectors. As an example, thermoset composites based on 2D braided preforms have been used by Dowty Propellers in the UK since 19871. Here a polyurethane foam core is combined with glass and carbon fibre fabrics, with the whole assembly over-braided with carbon and glass tows. The resulting preform is then impregnated with a liquid thermosetting polymer via resin transfer moulding (RTM). Compared with conventional materials, the use of textile composites in this application results in reduced weight, cost savings (both initial cost and cost of ownership), damage tolerance and improved performance via the ability to optimise component shape. A number of structures for the Airbus A380 passenger aircraft rely on textile composites, including the six metre diameter dome-shaped pressure bulkhead and wing trailing edge panels, both manufactured by resin film infusion (RFI) with carbon non-crimp fabrics, wing stiffeners and spars made by RTM, the vertical tail plane spar by vacuum infusion (VI), and thermoplastic composite (glass/ poly (phenylene sulphide)) wing leading edges. Probably the largest components produced are for off-shore wind power generation, with turbine blades of up to 60 metres in length being produced using (typically) noncrimp glass or carbon fabric reinforcements impregnated via vacuum infusion. Other application areas include construction, for example in composite bridges which offer significant cost savings for installation due to their low weight. Membrane structures, such as that used for the critically acclaimed (in architectural terms) Millennium Dome at Greenwich, UK, are also a form of textile composite. Numerous automotive applications exist, primarily for niche or high-performance vehicles but also in impact structures such as woven glass/polypropylene bumper beams.
This book is intended for manufacturers of polymer composite components, end-users and designers, researchers in the fields of structural materials and technical textiles, and textile manufacturers. Indeed the latter group should provide an important audience for this book. It is intended that manufacturers of traditional textiles could use this book to investigate new areas and potential markets. While some attention is given to modelling of textile structures, composites manufacturing methods and subsequent component performance, this is intended to be substantially a practical book. So, chapters on modelling include material models and data of use to both researchers and manufacturers, along with case studies for real components. Chapters on manufacturing describe both current processing technologies and emerging areas, and give practical processing guidelines. Finally, applications from a broad range of areas are described, illustrating typical components in each area, associated design methodologies and interactions between processing and performance.
The term ‘textile composites’ is used often to describe a rather narrow range of materials, based on three-dimensional reinforcements produced using specialist equipment. Such materials are extremely interesting to researchers and manufacturers of very high performance components (e.g. space transportation); an excellent overview is provided by Miravette2. In this book the intention is to describe a broader range of polymer composite materials with textile reinforcements, from woven and non-crimp commodity fabrics to 3D textiles. However random fibre-based materials, such as short fibre mats and moulding compounds, are considered outside the scope of this book. Similarly nano-scale reinforcements are not covered, primarily because the majority of these are in short fibre or platelet forms, which are not at present processed using textile technologies.
The first chapter provides a comprehensive introduction to the range of textile structures available as reinforcements, and describes their manufacturing processes. Inevitably this requires the introduction of terminology related to textiles; a comprehensive description is given in the Glossary. Also described are modelling techniques to represent textile structures, which are becoming increasingly important for prediction of textile and composite properties for design purposes. Chapter 2 describes the mechanical properties of textiles, primarily in the context of formability for manufacture of 3D components. The primary deformation mechanisms, in-plane shear, in-plane extension and through-thickness compaction, are described in detail, along with modelling techniques to represent or predict material behaviour. Chapter 3 describes similar behaviour for pre-impregnated composites (often termed prepregs), focusing on their rheology to describe their behaviour during forming. Chapter 4 demonstrates how the behaviour described in the previous two chapters can be used to model forming of textile composite components. This includes a thorough description of the theory behind both commercial models and research tools, and a discussion of their validity for a number of materials and processes. Chapters 5 and 6 concentrate on manufacturing technologies for thermoset and thermoplastic composites respectively. Manufacturing processes are described in detail and their application to a range of components is discussed.
In Chapter 7, resin flow during liquid moulding processes (e.g. RTM) is discussed. This starts with a description of the process physics but rapidly progresses to an important area of current research, namely optimisation and control of resin flow during manufacturing. Chapter 8 describes the mechanical properties of textile composites, including elastic behaviour, initial failure and subsequent damage accumulation up to final failure. The first half of the chapter provides an excellent primer on the mechanics of composites in general, and shows how well-established theories can be adapted to represent textile composites. The second half on failure and impact builds upon this and concludes with a number of applications to demonstrate the state of the art. In Chapter 9 flammability is discussed – an important topic given the typical applications of textile composites and the flammability associated with most polymers. Chapter 10 introduces concepts associated with technical cost modelling, which is used to demonstrate interactions between the manufacturing process, production volume and component cost. Finally the last four chapters describe a number of applications from the aerospace, construction, sports and medical sectors.