Preface Fibre reinforced polymer(FRP)composites are used in almost every type of advanced engineering structure,with their usage ranging from aircraft,helicopters and spacecraft through to boats,ships and offshore platforms and to automobiles,sports goods, chemical processing equipment and civil infrastructure such as bridges and buildings. The usage of FRP composites continues to grow at an impressive rate as these materials are used more in their existing markets and become established in relatively new markets such as biomedical devices and civil structures.A key factor driving the increased applications of composites over recent years is the development of new advanced forms of FRP materials.This includes developments in high performance resin systems and new styles of reinforcement,such as carbon nanotubes and nanoparticles.A major driving force has been the development of advanced FRP composites reinforced with a three-dimensional(3D)fibre structure.3D composites were originally developed in the early 1970s,but it has only been in the last 10-15 years that major strides have been made to develop these materials to a commercial level where they can be used in both traditional and emerging markets. The purpose of this book is to provide an up-to-date account of the fabrication. mechanical properties,delamination resistance,impact damage tolerance and applications of 3D FRP composites.The book will focus on 3D composites made using the textile technologies of weaving,braiding,knitting and stitching as well as by z- pinning.This book is intended for undergraduate and postgraduate students studying composite materials and also for the researchers,manufacturers and end-users of composites. Chapter I provides a general introduction to the field of advanced 3D composites. The chapter begins with a description of the key economic and technology factors that are providing the impetus for the development of 3D composites.These factors include lower manufacturing costs,improved material quality,high through-thickness properties,superior delamination resistance,and better impact damage resistance and post-impact mechanical properties compared to conventional laminated composites. The current and potential applications of 3D composites are then outlined in Chapter 1, including a description of the critical issues facing their future usage. Chapter 2 gives a description of the various weaving,braiding,knitting and stitching processes used to manufacture 3D fabrics that are the preforms to 3D composites.The processes that are described range from traditional textile techniques that have been used for hundreds of years up to the most recent textile processes that are still under development.Included in the chapter is an examination of the affect the processing parameters of the textile techniques have on the quality and fibre architecture of 3D composites. The methods and tooling used to consolidate 3D fabric preforms into FRP composites are described in Chapter 3.The liquid moulding methods used for consolidation include resin transfer moulding,resin film infusion and SCRIMP.The benefits and limitations of the different consolidation processes are compared for producing 3D composites.Chapter 3 also gives an overview of the different types of processing defects (eg.voids,dry spots,distorted binder yams)that can occur in 3D composites using liquid moulding methods.Preface Fibre reinforced polymer (FRP) composites are used in almost every type of advanced engineering structure, with their usage ranging from aircraft, helicopters and spacecraft through to boats, ships and offshore platforms and to automobiles, sports goods, chemical processing equipment and civil infrastructure such as bridges and buildings. The usage of FRP composites continues to grow at an impressive rate as these materials are used more in their existing markets and become established in relatively new markets such as biomedical devices and civil structures. A key factor driving the increased applications of composites over recent years is the development of new advanced forms of FRP materials. This includes developments in high performance resin systems and new styles of reinforcement, such as carbon nanotubes and nanoparticles. A major driving force has been the development of advanced FRP composites reinforced with a three-dimensional (3D) fibre structure. 3D composites were originally developed in the early 1970s, but it has only been in the last 10- 15 years that major strides have been made to develop these materials to a commercial level where they can be used in both traditional and emerging markets. The purpose of this book is to provide an up-to-date account of the fabrication, mechanical properties, delamination resistance, impact damage tolerance and applications of 3D FRP composites. The book will focus on 3D composites made using the textile technologies of weaving, braiding, knitting and stitching as well as by z￾pinning. This book is intended for undergraduate and postgraduate students studying composite materials and also for the researchers, manufacturers and end-users of composites. Chapter 1 provides a general introduction to the field of advanced 3D composites. The chapter begins with a description of the key economic and technology factors that are providing the impetus for the development of 3D composites. These factors include lower manufacturing costs, improved material quality, high through-thickness properties, superior delamination resistance, and better impact damage resistance and post-impact mechanical properties compared to conventional laminated composites. The current and potential applications of 3D composites are then outlined in Chapter 1, including a description of the critical issues facing their future usage. Chapter 2 gives a description of the various weaving, braiding, knitting and stitching processes used to manufacture 3D fabrics that are the preforms to 3D composites. The processes that are described range from traditional textile techniques that have been used for hundreds of years up to the most recent textile processes that are still under development. Included in the chapter is an examination of the affect the processing parameters of the textile techniques have on the quality and fibre architecture of 3D composites. The methods and tooling used to consolidate 3D fabric preforms into FRP composites are described in Chapter 3. The liquid moulding methods used for consolidation include resin transfer moulding, resin film infusion and SCRIMP. The benefits and limitations of the different consolidation processes are compared for producing 3D composites. Chapter 3 also gives an overview of the different types of processing defects (eg. voids, dry spots, distorted binder yams) that can occur in 3D composites using liquid moulding methods