Police officers and other personnel in the UK routinely wear body armour that provides protection from specific threats. Typically, 'soft' armours, usually formed from multiple layers of fabric, can protect wearers from fragmentation and low velocity (handgun) ballistic threats, while ‘hard’ armours, formed from ceramic and composite plates, offer protection from high velocity (rifle) threats. Protection from stab and/or slash attack is predominantly provided by utilising chain mail and laminated solutions. The question has been raised however, of what would happen when armour is overmatched with a greater threat than it is designed to protect against. A limited number of studies have been published in the open source literature regarding the overmatching of soft body armour. This research aims to increase the understanding of overmatching, by investigating the effect of both i) soft fabric body armour designed to protect from handgun ammunition being challenged by high velocity rifle projectiles and ii) knife and spike resistant armour protecting against low velocity handgun projectiles. A subsection of the research considered three tissue simulants in order to find the most suitable for investigating the effects of overmatching armour. A method for recording the damage produced in the simulants was also developed; from which comparison of damage to different targets was possible. Following the tissue simulant investigation, gelatine blocks 10% in concentration were selected and used to investigate the overmatching of two types of UK police body armour. Three different arrangements were setup, namely 10% gelatine blocks 500mm, 10% gelatine blocks 250mm in length, and porcine thoracic walls arranged to simulate a thorax. Testing blocks 500mm in length was a set-up typical to ballistic investigations; the blocks were capable of capturing the majority of the projectiles’ damage, with the damage produced in both unprotected and protected (on the front face only) targets compared. Based on anthropometric measurements, testing 10% gelatine blocks 250mm in size was more representative of a torso sized target. With the blocks smaller, armour was placed on both the front and back face of targets. This is more representative of how armour would be worn in a real life scenario; patrolling UK police officer wearing armour that protects both the front and back of their torso. Finally, the use of porcine samples arranged to simulate both protected and unprotected thoraxes enabled comparisons of the damage seen in homogenous tissue simulants to damage in non-homogenous material typical to those found in the human torso. The outcomes from testing three different targets with two ammunition and armour combinations revealed the effect of overmatching armour is not one that can be generalised and predicted for all overmatching scenarios. The presence of armour on the rear face of targets based on typical measurements of human chest depth, increased the chances of the projectiles tested remaining within the targets. / EPSRC

Darbe yra analizuojamos Vilniaus pilių teritorijoje, archeologinių tyrimų metu, rastos šarvų detalės. Šioje teritorijoje aptiktas pakankamai didelis kiekis įvairiausių šarvų detalių, kurios datuojamos nuo XIV a. antrosios pusės iki XVII a. antros pusės. Publikacijų, skirtų Viduramžių ir renesanso ginkluotei, Lietuvoje yra labai nedaug, o archeologinių tyrimų metu aptiktai šarvuotei – išvis nėra. Todėl šio darbo objektu pasirinktos Vilniaus Pilių teritorijoje, archeologinių tyrimų metu, aptiktos šarvuotės detalės. Darbo tikslas yra visapusiškai išanalizuoti visas Vilniaus pilių teritorijoje aptiktas šarvų detales, kiek įmanoma tiksliau jas tipologizuoti, bei datuoti. Vėliau, pasitelkus gautus duomenis ir ieškant analogų, įvertinti kiekvieno šarvų tipo populiarumą Vilniaus pilių įgulos tarpe. Taip pat, šioje teritorijoje aptiktą šarvuotę įvertinti bendrame Europos šarvuotės kontekste. Kadangi šarvuotė yra pakankamai sudėtingas ir problematiškas objektas archeologijoje, o lietuvių tyrinėtojų darbų skirtų šarvams kol kas nėra, šiame darbe buvo naudojamasi užsienio autorių tyrinėjimais ir jų tyrimo metodais. Tyrimo metu Vilniaus pilių teritorijoje aptiktos šarvų detalės buvo tipologizuotos ir datuotos. Išryškėjo penki pagrindiniai šarvuotės tipai: grandininiai šarvai, brigandinos, lameliaro ir žvyninės konstrukcijų bei plokštiniai šarvai. XIV a. pab. – XVI a. pirmoje pusėje šarvuotėje pastebima didesnė rusiškų žemių įtaka, tikriausia atsiradusi dėl LDK vykdytos ekspanijos į rytų... [toliau žr. visą tekstą] / Vilnius’ castle territory presents a unique opportunity to study our past. Archeological research in this previously undescribed area has unearthed unprecedented amounts of body armor used by the Lithuanian armies from the second part of the XIV century to the end of the XVII century. As a result, these findings highlight the darkest aspects surrounding the history of Middle Ages and Renaissance armament in Lithuania. In this paper we present detailed analysis of these body armor pieces. Serving as a mediator of east and west Lithuanian armory design incorporates influences of two temporally distinct trends. The earliest design influence came from the Eastern Slavic land, while the latest came from the Western Europe. In both cases, hired armies of mercenaries where the carriers of these design influences. This is particularly true in the case of mercenaries emanating from Europe. The scope of these influences is remarkable. Castle’s armory reflects practically all of the changes that were taking place among European armory designs at the time. Overall, discovered armory pieces can be divided into five distinct types of body armor: chain mail, lamellar, scale armor, plate armor and brigandine. Use of brigandine in particular seems to coincide with its use in the Western Europe providing a direct link between the influences of the Western Europe on the development of armory in Lithuania. In the end of XIV and beginning of XVI century armory underwent a noticeable Russian... [to full text]

No description available.

Police officers and other personnel in the UK routinely wear body armour that provides protection from specific threats. Typically, 'soft' armours, usually formed from multiple layers of fabric, can protect wearers from fragmentation and low velocity (handgun) ballistic threats, while ‘hard’ armours, formed from ceramic and composite plates, offer protection from high velocity (rifle) threats. Protection from stab and/or slash attack is predominantly provided by utilising chain mail and laminated solutions. The question has been raised however, of what would happen when armour is overmatched with a greater threat than it is designed to protect against. A limited number of studies have been published in the open source literature regarding the overmatching of soft body armour. This research aims to increase the understanding of overmatching, by investigating the effect of both i) soft fabric body armour designed to protect from handgun ammunition being challenged by high velocity rifle projectiles and ii) knife and spike resistant armour protecting against low velocity handgun projectiles. A subsection of the research considered three tissue simulants in order to find the most suitable for investigating the effects of overmatching armour. A method for recording the damage produced in the simulants was also developed; from which comparison of damage to different targets was possible. Following the tissue simulant investigation, gelatine blocks 10% in concentration were selected and used to investigate the overmatching of two types of UK police body armour. Three different arrangements were setup, namely 10% gelatine blocks 500mm, 10% gelatine blocks 250mm in length, and porcine thoracic walls arranged to simulate a thorax. Testing blocks 500mm in length was a set-up typical to ballistic investigations; the blocks were capable of capturing the majority of the projectiles’ damage, with the damage produced in both unprotected and protected (on the front face only) targets compared. Based on anthropometric measurements, testing 10% gelatine blocks 250mm in size was more representative of a torso sized target. With the blocks smaller, armour was placed on both the front and back face of targets. This is more representative of how armour would be worn in a real life scenario; patrolling UK police officer wearing armour that protects both the front and back of their torso. Finally, the use of porcine samples arranged to simulate both protected and unprotected thoraxes enabled comparisons of the damage seen in homogenous tissue simulants to damage in non-homogenous material typical to those found in the human torso. The outcomes from testing three different targets with two ammunition and armour combinations revealed the effect of overmatching armour is not one that can be generalised and predicted for all overmatching scenarios. The presence of armour on the rear face of targets based on typical measurements of human chest depth, increased the chances of the projectiles tested remaining within the targets.

Two studies involving different applications of motion analysis and force measurement techniques are presented. The first study provides data on typical loads on the upper limb, and the muscle and joint forces which oppose them. The second presents parameters defining the biomechanics of knife stab attacks in order to specify standards for the testing of stab resistant body armour. A three dimensional, mathematical model of the elbow and wrist joints, including 15 muscle units, 3 ligaments and 4 joint forces, has been developed. A new strain gauge transducer has been developed to measure functional grip forces. The device measures radial forces divided into six components and forces of up to 250N per segment can be measured with an accuracy of «1%. Ten normal volunteers from within the Bioengineering Unit were asked to complete four tasks representing occupational activities, during which time their grip force, was monitored. Together with kinematic information from the six-camera Vicon data, the moment effect of these loads at the joints was calculated. These external moments are assumed to be balanced by the internal moments, generated by the muscles, passive soft tissue and bone contact. The effectiveness of the body's internal structures in generating joint moments was assessed by studying the geometry of a simplified model of the structures, where information about the lines of action and moment arms of muscles, tendons and ligaments is contained. The assumption of equilibrium between these external and internal joint moments allows formulation of a set of equations from which muscle and joint forces can be calculated. A two stage, linear optimisation routine minimising the overall muscle stress and the sum of the joint forces has been used to overcome the force sharing problem. Humero-uInar forces of up to 1600N, humero-radial forces of up to 800N and wrist joint forces of up to 2800N were found for moderate level activity. The model was validated by comparison with other studies. A wide range of parameters defining the biomechanics of knife stab attacks has been measured in order to specify standards for the testing of stab resistant body armour. Stab styles based on reported incidents provided more realistic data than had previously existed. A six camera Vicon motion analysis system and specially developed force measuring knife were used to measure the parameters. Twenty volunteers were asked to stab a target with near maximal effort. Three styles of stab were used: a short thrust forward, a horizontal style sweep around the body and an overhand stab. The body holding the knife u-as modelled as a series of rigid segments: trunk, upper arm, forearm and hand, and knife. The calculation of the velocities of theses egments, and knowledge of the mass distribution from biomechanical tables, allowed the calculation of the segment energy and momentum values. The knife measured four components of load: axial force (along the length of the blade), cutting force (parallel to the breadth of the blade), lateral force (across the blade) and torque (twisting action) using foil strain gauges. The 95th Percentile values for axial force and energy were 1885N and 69J respectively.

A Primary objective of the present research is the development of robust CAE (Computer-Aided Engineering)-based approaches for designing armour plates subjected to ballistic impact by small-calibre hardened peojectiles with or without a protective sheath. Amongst the challenges in simulation is the capturing of target plate material behaviour at high strain rates with possibilities of adiabatic heating. A comprehensive numerical study carried out has resulted in the identification of simulation guidelines using a commercially available explicit finite element anlaysis solver (viz. LS_DYNA). The interferences thus drawn in terms of modeling approach 9I.e. shell, solid or axisymmetric or a mixed representation). Mesh density and element type, contact condition, and constitutive model 9I.e. discrete strain-rate based, Cowper-Symonds, or Johnson-Cook) with failure criteria are verifiable and greatly beneficial for armour plate design. Confidence in the suggested procedures has been obtained through extensive correlation of numerical results with experimental residual velocities and ballistic limits as well as projectile and target plate failure modes. A wide range of impact velocities has been considered (from a low velocity of about 5m/s to an ordnance range velocity of 800+ m/s). Target plates made of variants of mild steel and aluminium alloys have been studied. The simulation approaches have been applied to single-layered as well as multi-layered target plates. Although a majority of the comparisons has been made against published test results, a new ballistic impact testing facility has been set up in course of the current research and excellent correlation of numerically predicted residual velocities and failure modes has been obtained against the tests carried out for aluminium plate using the latter facility. A unique feature of the current experimental effort is the capturing of the complete trajectory of projectile beginning with oblique impact through subsequent perforation/ricochet. Furthermore, projectiles of various nose-shapes such as ogival, conical, hemispherical and blunt have been employed. The power of simulation has been demonstrated with the help of a number of parametric studies with variables such as plate thickness and material properties, as well as projectile mass and diameter, and obtaining physically consistent results. Additionally, existing semi empirical models for residual velocity and ballistic limit prediction have been reviewed, and new user-friendly models have been proposed based on energy conservation and predominant shear plugging failure mode of target plate. Finally, the goal of applying the present research work as a design tool can be well-served by packaging the knowledge gathered here in the form of a user-friendly guide with a graphical user interface(GUI). To this end, an application using MS windows VC++ utilities has been created with the functionalities of: (a) viewing reference LS-DYNA input data files for selecting typical problems of impact on steel and aluminium plates; (b) computing complete lists of strain rate-based material quantities required in LS-DYNA material models like discrete strain rate-based, Cowper-Symonds and Johnson-Cook by specifying the minimum number of easily available quasi-static properties (such as elastic modulus, yield and ultimate strengths, etc.), and (c) estimating residual velocities using the semi-empirical relations for steel and aluminium plates derived in the current work.

Le travail de la thèse porte sur une étude globale des interactions qui surgissent sur le système projectile/protection/cible lors d’un impact balistique non perforant. L’objectif principal consiste à l’analyse et à l’évaluation des modes d’endommagement des projectiles et des protections d’une part, et les déformations occasionnées sur la cible, d’autre part. Une étude expérimentale a permis la caractérisation mécanique des différents matériaux utilisés à savoir : la gélatine, la plastiline, ainsi que l’analyse des réponses balistiques utilisant des protections en composite, en aluminium et textiles. L’accent a été mis sur la recherche des lois de comportement appropriées pour les différents composants du système balistique utilisant des multi-matériaux. Une simulation numérique du thorax humain a été développée, exploitée et validée sur la base d’un impact non pénétrant. La simulation numérique a été réalisée en prenant en compte à la fois le thorax et les différents organes du corps humain en intégrant aussi la présence de protections. / This work deals with interactions occurring on the projectile/protection/target system during a non-perforating ballistic impact. The first main goal concerns the analysis and evaluation of the processes’ damage projectiles and protections. The second one concerns the deformation of the target. An experimental study has allowed the mechanical characterisation of different used materials: the gelatine, the plastilina, and the analysis of the ballistic response of the composite, aluminium and textile based-protections. The research carried out here is focused on the appropriate material laws of different components of the ballistic system implicating the multi-materials. A numerical simulation of the human thorax has been developed, implemented and validated thanks to a non-penetrating ballistic impact. The numerical simulation has been realised by taking into account of both the thorax and the different organs of the human body protected by a ballistic protection.

Five materials, copper (two versions), iron, and armour plate steel (two versions) have been tested at different strain-rates and temperatures. All tests were in compression. The materials were studied to provide experimental data for input into hydrocode models of armour behaviour by the Defence Research Agency, Fort Halstead. A wide selection of metals was examined so that comparisons could be drawn between modelling the behaviour of face centred and body centred cubic metals, and to carry out a broader investigation into how the results obtained were affected by the test methods. Experiments were performed at temperatures from -100°C to 20°C and mean plastic strain-rates from 10-3 to 103 S-l, using a Split Hopkinson Pressure Bar (SHPB) system for high strain-rates and a Hounsfield 50 kN machine for quasistatic conditions. The stress-strain behaviour of the materials as a function of temperature and strain-rate was then determined. The effects of interfacial friction on the measured compreSSlve properties of copper and the armour plate steels have been investigated. Since the coefficient of friction was the critical parameter, ring tests were carried out and the Avitzur analysis applied. In general, the coefficient of friction decreased with increasing strain-rate and temperature. The tested specimen's appearance indicated the same friction trends. Hydrocode modelling of the SHPB system produced corrections to the flow stress, to compensate for interfacial friction, that agree well with those predicted by the Avitzur analysis. Deformed finite element mesh plots analysed in conjunction with barrelled specimens have given a clearer insight into the mechanisms of interfacial friction. The Armstrong-Zerilli constitutive models have been applied to copper, iron and armour plate steel results corrected for thermal softening and specimen-platen interfacial friction. These models have been shown to provide a reasonable description of the materials' behaviour. The research investigation has shown that in order to obtain fundamental stressstrain behaviour of the materials, then corrections must be applied, which can be quite significant. These corrections must take into account the effects of material thermal softening and the specimen-platen interfacial friction.

This thesis focuses on the development of a new technique which enables a novel type of front panel for female body armour to be engineered, providing female contour, high level protection, and therefore comfort in wearing. The traditional cutting and stitching method can be used to form a dome shape to accommodate the bust area but it gives rise to weakness against projectile impact at the seams. A novel type of fabric with the advantage in mouldability is needed as an alternative to the conventional plain woven fabric in making female body armour without the need of cutting or folding but ease in manufacture. Dome-shaped fabric and angle-interlock woven fabric are two potential candidates. The analysis and comparisons determine the selection of the fabric with superior dome depth which is more suitable for the female body armour application. Ballistic evaluations on the selected fabric were carried out from two aspects: the overall ballistic performance investigation and the parametric study. The result provided a better understanding of kinetic energy absorption capability of single-piece selected fabrics. Additionally, the ballistic performance of fabric panels was further evaluated in the factory in order to ensure the selected fabric could achieve the commercial requirement. After the investigations of mouldability and ballistic resistance of the selected fabric, a mathematical model was created, which determines the pattern geometry for the front panel of the female body armour. This mathematical model takes the body figure size and bra size as the input, and the output is the profile of the front panel of female body armour. This work enables the speedy creation of a front panel of the female body armour in the selected fabric. This is an important advance and a novel approach for making seamless female body armour with satisfactory ballistic performance.

No description available.