Overview

Ceramic materials are commonly used to provide ballistic protection for civilian and military vehicles, aircraft, and personnel. Ever since the 1960s their relatively low densities and high hardness values have been attractive to armour designers. However, ceramic materials are inherently brittle and therefore careful thought must be given to the way in which they are applied.

The penetration mechanisms of different projectiles into these materials are quite complex! Understanding the way in which these materials interact with the projectile is central to the design of an efficient armour system. This book introduces some of the more pertinent lessons learnt over the years. It also provides an insight into the defeat mechanisms that ceramic materials employ when struck by various projectiles. This book is primarily aimed at the military student, end user, and enthusiastic amateur alike who are interested ceramic armour materials and systems. The content is based loosely on the author’s notes compiled for various post-graduate defence technology courses and short courses on survivability – where the students have been mostly serving military officers.

This book is by no means comprehensive for the sake of brevity and it is principally an introductory text. As such, in Chapter 2 there is a chapter on material properties and in Chapter 3 an overview is provided of the types of threats that a ceramic armour system may encounter. It is primarily aimed at the military student, end user, and enthusiastic amateur alike who are interested in an insight into this technology.

There are ten chapters. Chapter 1 discusses the simple methods that are used in armour design and introduces ceramic materials and their application in armour. Chapter 2 discusses the properties of materials in light of their measurement and meaning and Chapter 3 provides an overview of the typical threats that a ceramic armour system may encounter. Chapter 4 examines the various ways that scientists and engineers assess armour performance and Chapter 5 discusses the types of ceramics that are available for armour applications and the methods for manufacturing them. The impact and penetration mechanisms of various projectiles into ceramic materials are discussed in Chapter 6 along with the more pertinent armour failure mechanisms. In Chapter 7 we look at the factors that govern performance and in Chapter 8 we examine other materials and systems that are used instead of, and in conjunction with, ceramic armour. In Chapter 9 we discuss a few methods for simulating the failure of ceramic materials that have been loaded dynamically and finally, in Chapter 10 we close with an Epilogue.

Paul Hazell lectures for Cranfield University teaching on post-graduate courses on defence technology at the UK’s Defence Academy at Shrivenham and the Australian Defence Force Academy in Canberra. His research and consultancy interests are in experimental and numerical terminal ballistics.

Preface

Ceramic materials are commonly used to provide ballistic protection for civilian and military vehicles, aircraft and personnel. They have been used as part of a system to defeat all sorts of military threats from bullets to main battle tank ammunition.

This book intends to cover a range of different subjects relevant to ceramic armour design. It also intends to introduce the ways in which such an armour system defeats various types of projectiles. This book is by no means comprehensive for the sake of brevity and it is principally an introductory text. As such, in Chapter 2 there is a chapter on material properties and in Chapter 3 an overview is provided of the types of threats that a ceramic armour system may encounter. It is primarily aimed at the military student, end user, and enthusiastic amateur alike who are interested in an insight into this technology.

There are ten chapters. Chapter 1 discusses the simple methods that are used in armour design and introduces ceramic materials and their application in armour. Chapter 2 discusses the properties of materials in light of their measurement and meaning and Chapter 3 provides an overview of the typical threats that a ceramic armour system may encounter. Chapter 4 examines the various ways that scientists and engineers assess armour performance and Chapter 5 discusses the types of ceramics that are available for armour applications and the methods for manufacturing them. The impact and penetration mechanisms of various projectiles into ceramic materials are discussed in Chapter 6 along with the more pertinent armour failure mechanisms. In Chapter 7 we look at the factors that govern performance and in Chapter 8 we examine other materials and systems that are used instead of, and in conjunction with, ceramic armour. In Chapter 9 we discuss a few methods for simulating the failure of ceramic materials that have been loaded dynamically and finally, in Chapter 10 we close with an Epilogue.

The content is based loosely on the author’s notes compiled for various post-graduate defence technology courses and short courses on vehicle survivability—where the students have been mostly serving military officers.

Table of contents

CONTENTS
1	INTRODUCTION	1
1.1	Disruptor or Absorber?	3
1.2	The Disposition of Armour	5
1.3	Why Ceramic?	6
1.4	Applications	9
1.5	Summary	10
2	PROPERTIES OF MATERIALS	13
2.1	Elasticity	13
2.2	Strength and Toughness	14
2.3	Weibull Statistics	18
2.4	Hardness	19
2.5	Dynamic Behaviour of Materials	21
2.6	Summary	24
3	ASSESSMENT OF THE THREAT	27
3.1	Small-arms Ammunition (< 20 mm)	27
3.2	Higher Calibre KE Rounds Including ‘Medium Calibre’ (>20 mm)	31
3.3	Shaped Charge	34
3.4	Explosively Formed Projectiles	35
3.5	High Explosive Squash Head (HESH)	37
3.6	Fragments	39
3.7	Summary	39
4	EVALUATING ARMOUR MATERIALS AND SYSTEMS	41
4.1	General Points	41
4.2	Areal Density	42
4.3	The Ballistic-limit Test	43
4.4	The Ballistic Pendulum Test	45
4.5	The DOP Test	45
4.6	Summary	48
5	PROCESSING TECHNIQUES FOR ARMOUR APPLICATIONS	49
5.1	The Structure of Ceramics	49
5.2	Processing Routes for Armour Ceramics	51
5.3	Ceramic Choice	54
5.4	Transparent Armour Materials	56
5.5	Summary	60
6	IMPACT AND PENETRATION OF CERAMIC MATERIALS	63
6.1	Cracking	63
6.2	Attack by Small-Calibre Ammunition	64
6.3	Attack by Medium- to Large-calibre Ammunition	68
6.4	Hydrodynamic Penetration	72
6.5	Attack by Shaped-charge Warheads	77
6.6	Stress Wave Propagation Issues	78
6.7	Summary	88
7	FACTORS THAT GOVERN PERFORMANCE	93
7.1	Tile Thickness and Areal Geometry	93
7.2	The Influence of Obliquity	95
7.3	The Mechanical Properties of the Ceramic	97
7.4	Coupling	100
7.5	Confinement	101
7.6	Multi-hit Capability	101
7.7	Summary	103
8	ALTERNATIVE MATERIALS AND SYSTEMS	107
8.1	Steel as Armour	107
8.2	Aluminium Alloy Armour	112
8.3	Titanium Alloys	116
8.4	Composite Materials	117
8.5	Reactive Armour Systems	120
8.6	Summary	124
9	COMPUTATIONAL MODELLING ISSUES	127
9.1	Simulating the Material Strength	129
9.2	Simulating Material Failure	130
9.3	Summary	132
10	EPILOGUE	135
	GLOSSARY	137
A	REVISION QUESTIONS	149
B	BALLISTIC EFFICIENCY VALUES FROM DOP TRIALS	155
	BIBLIOGRAPHY	163
	INDEX	165

Sample Chapter

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