Stab resistant body armour had been used throughout history, with examples ranging from animal hide construction to the moulded Polycarbonate units typically used by United Kingdom (UK) Police Officers. Such protective articles have historically, and continue to present a number of issues which have shown to impair the operational performance of its wearer including but not exclusive to poor thermal regulation, large masses, and reduced manoeuvrability. A number of developments have been made in an attempt to minimise the effects of such issues. One potential solution yet to be fully explored is the utilisation of Additive Manufacturing (AM) technologies. In recent years the use of such manufacturing technologies, particularly Laser Sintering, has successfully demonstrated their suitability for a range of high performance applications ranging from Formula 1® to aerospace. Due to the fundamental additive nature of AM build processes, the utilisation of such technologies have facilitated the realisation of design concepts that are typically too expensive, difficult or impossible to create using traditional manufacturing processes. In order for AM technologies to be used for the generation of stab resistant body armour a number of historical issues and performance characteristics fundamental to ensure stab resistance is achieved must be satisfied. This body of research firstly evaluated the stab resistive performance of two of the most common materials suitable for Laser Sintering as highlighted by an initial review of AM technologies. Once an appropriate material had been highlighted it was used as the basis for further experimental testing. Such tests focussed on minimising the material thickness required to maintain an appropriate level of stab resistance within United Kingdom Home Office Scientific Development Branch (HOSDB) KR1-E1 requirement of 24 Joules of stab impact energy. Test results demonstrated that specimens manufactured from Duraform EX® required a minimum single layer thickness of 11.00 mm, and a dual layer total thickness of 9.00 mm to provide an appropriate level of stab protection within the HOSDB KR1-E1 standard. Coupled with the results generated from an investigation identifying the overlapping/imbricated assembly angle required to maintain an appropriate level of coverage across a scale structure, the stab resistant characteristics initially identified were used for the development of an imbricated scale-like assembly. Additional design features were also investigated to further minimise the total thickness of the final element design and corresponding assembled imbricated structure such features included angling strike surfaces and integrating a dual layered structure within individual elements. When the finalised imbricated assemblies were stab tested, they successfully demonstrated levels of stab resistance to the UK HOSDB KR1-E1 impact energy of 24 Joules.

L'objectif de cette thèse est d'observer l'impact des coups de couteaux sur différents tissus en aramide et d'analyser les facteurs influents. On peut se défendre d'une attaque mais une blessure ne peut être complètement évitée. L'objectif est d'absorber un maximum d'énergie, de façon à réduire le risque de blessure. Les mécanismes de perforation par une lame sont complexes. L'étude a révélé une demande dans ce domaine, car la plupart des solutions proposent des armures lourdes contenant du textile. Cet assemblage de matériaux a des inconvénients, comme le poids trop élevé et le manque de souplesse. D'autres chercheurs recommandent des solutions textiles parce qu'elles sont souples et déjà utilisées dans le domaine balistique. Les recherches menées pour cette thèse ont pour but de contribuer au développement de types de textile résistant aux coups de couteaux. C'est la raison pour laquelle, non seulement les propriétés de la matière textile doivent être analysées, mais aussi l'attaque au couteau en elle-même, pour développer une meilleure protection. Il a été démontré que beaucoup de facteurs influent sur le niveau de protection et rendent sa perception difficile. Des recherches ont été réalisées pour évaluer les paramètres de test, qui sont définis dans le test standard, mais aussi pour ceux qui n'y sont pas définis. / The research goal of this thesis is to examine various aramid fabrics with regard to their stabbing behaviour and to find influencing factors to this. An attack can only be inhibited, but an injury cannot be completely prevented. The goal is always to absorb as much energy as possible, so that the penetration is thus reduced and the risk of injury decreases. The stab mechanism is a complex and variable process. The review showed the demand on research in this area, because the most solutions involve hard body armour parts in combination with fibrous materials. This material combinations show many disadvantages with regards to the high weight and the missing flexibility. Other researchers also recommend textile solutions, because they are flexible and in the field of ballistic panels they are already used. The investigations carried out within this thesis are done to contribute to the development of pure textile stab-resistant panels. Therefore the interdependencies between the physical properties of the material but also the mechanism during a stab attack have to be recognized, to developed higher protection levels. It was shown, that the multitude of factors causes the problem to define a level of protection. General investigations were done to analyse the test parameters, which are defined in the test standard but also this one, which are missing.