Advanced Fibrous Composite Materials for Ballistic Protection

Xiaogang Chen

• Publisher: Woodhead Publishing
• Year: 2016
• Print ISBN: 9781782424611
• eBook ISBN: 9781782424840
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

Advanced Fibrous Composite Materials for Ballistic Protection provides the latest information on ballistic protection, a topic that remains an important issue in modern times due to ever increasing threats coming from regional conflicts, terrorism, and anti-social behavior.The basic requirements for ballistic protection equipment are first and foremost, the prevention of a projectile from perforating, the reduction of blunt trauma to the human body caused by ballistic impact, the necessity that they are thermal and provide moisture comfort, and that they are lightweight and flexible to guarantee wearer's mobility.The main aim of this book is to present some of the most recent developments in the design and engineering of woven fabrics and their use as layering materials to form composite structures for ballistic personal protection. Chapter topics include High Performance Ballistic Fibres, Ultra-High Molecular Weight Polyethylene (UHMWPE), Ballistic Damage of Hybrid Composite Materials, Analysis of Ballistic Fabrics and Layered Composite Materials, and Multi-Scale Modeling of Polymeric Composite Materials for Ballistic Protection.- Contributions from leading experts in the field- Cutting edge developments on the engineering of ballistic materials- Comprehensive analysis of the development and uses of advanced fibrous composite materials

1

Introduction

X. Chen University of Manchester, Manchester, United Kingdom

Abstract

This chapter aims to provide a general introduction to advanced fibrous composite materials for ballistic protection, covering the history and the state of the art of ballistic protection, types of ballistic protection equipment, and the engineering of ballistic materials. Some background details and novel developments in ballistic materials engineering are provided. Ballistic protective materials, for either body armour, helmet, or military vehicle panels, face major challenges, which are providing protection and being lightweight. The chapter emphasises the importance of the high-performance fibres for ballistic protection, and it also explains the necessity of manipulating the structural features of the ballistic materials for improved performance. This chapter also draws attention to the possibility of novel materials and technologies for ballistic protection.

Keywords

Armour; Ballistic protection; Composite materials; Engineering design; Future technology; High-performance fibres

1.1. Background

Military confrontations and wars never seem to stop throughout world history. The level of personal and property protection against the threats in the battlefields and in riot situations has been developed in line with the advancement of the attacking weapons. At different times in history, different materials have been used for protection against attacks according to the types of attacking weapons. Among many, leather, fabrics, metal, and wood have played important roles in personal and property protection. In addition, these materials have been manufactured into different shapes with internal structures to optimise the effect of protection. For example, metal has been used as a shell to protect the torso, as well as chain mail for increased armour flexibility (Chen and Chaudhry, 2005; Carother, 1988).

Soldiers were confronted with greater ballistic threats after the invention of the firearm in comparison to other weapons (Tam and Bhatnagar, 2006). Strong and lightweight materials were sought for a new generation of ballistic protection. Along with the invention of synthetic fibre nylon in the 1930s, this much stronger fibre was involved in the creation of the flak vest towards the end of World War II. This technology brought about enhanced protection against firearms, lightweight, and flexibility (Dunn, 2008). Since then, the fibre-based materials have dominated the engineering of personal protective equipment. Along with the progress of textile-reinforced composites, the fibre-based composites also play more important roles as body materials for military vehicles and aircraft. This route for engineering ballistic materials drew much attention when various advanced fibrous materials were invented in modern times, such as aramid fibres (eg, Kevlar and Twaron), ultra-high molecular weight polyethylene (UHMWPE) fibres (Dyneema and Spectra), PBO fibres (eg, Zylon) and PIPD fibres (eg, M5). However, Zylon is reported to be susceptible to hydrolytic and photolytic degradation, and therefore it is not suggested for use in ballistic protection (U.S. Department of Justice, 2005). M5 fibre has similar but less degradation than PBO from exposures to ultraviolet radiation and elevated moisture, while it may exhibit brittleness at ballistic loading rate (Scott, 2006). Such being the case, the fibres for ballistic protection are dominantly the aramid and UHMWPE fibres.

Ballistic protective materials in this context are mainly used for personnel and vehicle protection, for which agile movements of the personnel and vehicles are vital for carrying out their missions. Therefore, high protective performance against ballistic impact and lightweight are probably the two most important requirements. As a matter of fact, the evolution of modern ballistic materials witnessed the effort and progress in technologies for creating strong and lightweight materials. A modern time soldier in the battlefield could carry up to a 70 kg load, of which 14–17 kg comes from the body armour system (Conference Communication, 2009). There have been campaigns in different countries to work to reduce the weight of the body armours while retaining or even improving the ballistic performance. Ballistic composites are used in military vehicles for territory armies, navies, and air forces, therefore lightweight of the ballistic composites is keenly sought for uncompromised protection at the same time.

1.2. Types of ballistic protective equipment and materials

Ballistic threats refer to those caused by projectiles flying at high velocity, such as bullets, shrapnel, and other similar objects, usually associated with military actions. Ballistic materials are used basically in soft and rigid forms in protection applications.

Soft body armour is made by layering dry ballistic fabrics. This technology is particularly used for body armour used for low levels of ballistic threats, such as NIJ (National Institute of Justice) levels I, IIa, and II, and it offers suitable flexibility for body movement. The most commonly seen soft body armour is for the torso, and there is also soft armour designed to protect neck and groin areas. When facing higher levels of ballistic threats, hard ballistic s are used in conjunction with the soft armour. The hard ballistic plates could be made of metal, ceramics, and textile composites. Special body protective clothing systems are available for special tasks. The system used for explosive ordnance disposal covers the whole body, and it must be made from soft protective materials to allow free body movement (Scott, 2005).

Military helmets are another piece of important equipment to prevent casualties. Helmets used to be made of steel, which has been replaced by textile reinforced ballistic composites for higher ballistic performance and lightweight. Due to the doubly curved nature of the helmet, protective fabrics are cut into patterns and then patched together to form the helmet shell. The composite helmet represents substantial progress, but the fibre discontinuity in the helmet could be a concern. Chen and his colleagues worked on the formation of helmet shells from a single piece of reinforcing fabric and demonstrated the advantages in improving impact protection (Roedal and Chen, 2007; Zahid and Chen, 2014).

Fibre-based ballistic composites attract much attention for various types of military applications because of the advantages such materials offer. Not only have the ballistic composites demonstrated high mechanical properties including high-velocity impact, the fibre-based composites enable weight savings, high payload and fuel efficiency, high performance, and speed capability. Textile composites, however, are a complex materials system; the mechanical performance and response to ballistic impact are affected by many factors, such as fibre, resin, fibre-resin interface, as well as the construction of the textile reinforcements (Cheeseman and Bogetti, 2003). Investigations into textile composites are carried out based on two approaches: experimental and numerical. The ultimate function of the ballistic composites is to prevent the high-velocity projectile from piercing the material. It is imperative to understand mechanisms for hindering the projectile by taking energy off the projectile. High-performance fibres and compactable resins have been selected for this application. A large volume of the composites are expected to be involved in absorbing energy from the impacting projectile, therefore control over the stress wave propagation and composite delamination will be important engineering ...

Table of contents

• Cover image
• Title page
• Table of Contents
• Related titles
• Copyright
• List of contributors
• Woodhead Publishing Series in Composites Science and Engineering
• 1. Introduction
• 2. ARAMIDS: ‘Disruptive’, open and continuous innovation
• 3. High-performance ballistic fibers: Ultra-high molecular weight polyethylene (UHMWPE)
• 4. Fabrics and composites for ballistic protection
• 5. Ballistic damage of hybrid composite materials
• 6. Modelling of 3D woven fabrics for ballistic protection
• 7. Measurements of dynamic properties of ballistic yarns using innovative testing devices
• 8. Analysis of woven fabric composites for ballistic protection
• 9. Failure mechanisms and engineering of ballistic materials
• 10. Narrow fabrics for enhanced ballistic performance
• 11. Multiscale modeling of polymeric composite materials for ballistic protection
• 12. Stab characterization of STF and thermoplastic-impregnated ballistic fabric composites
• 13. Polyolefin film–reinforced composites for personal protection
• 14. Ballistic performance evaluation of woven fabrics based on experimental and numerical approaches
• 15. Thermoplastic matrix combat helmet with carbon-epoxy skin for ballistic performance
• 16. Numerical analysis of the ballistic performance of textile fabrics
• 17. Damage modeling of ballistic impact in woven fabrics
• Index