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

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.

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.

Soft body armour is usually constructed by layering numerous layers of the same fabric. Such a construction, however, may not be the most efficient in providing the required protection due to different ballistic resistant efficiency of each layer. This research aims to optimise the construction of the panels for soft body armour by hybridisation in order to achieve the improvement of ballistic performance and reductions in weight. Twaron woven fabrics with different weave structures and Dyneema uni-directional (UD) laminates were used as components for the hybrid design of panels. Two complementary research approaches were employed in this study, namely the empirical method and the Finite Element (FE) analysis. The first part of this research systematically revealed the different ballistic characteristics of each layer in different positions of an armour panel and the way of energy absorption in the panel. The fabric layers in the front, middle and back of the panel exhibited different extent of transverse deformation and stress distribution. The energy absorption increases from front layer and reaches to the maximum value in the last perforated layer and then decreases gradually in the following back layers. Such pattern of energy absorption was not affected by either the striking velocity or the total number of layers in the panel, but the position, in the thickness, of the peak value in energy absorption was shifted more towards the back of the panel when the striking velocity increases. Such findings contribute to the understanding of different ballistic responses in different positions of an armour panel under ballistic impact. The second part of this research put forward a new hybrid design concept. According to above theoretical understandings of different ballistic characteristics in different positions of an armour panel, the fabric layers in the panel were discretely divided into three groups. In addition to the performance of different components for the panel and the influences of the laying sequence, a procedure for constructing hybrid armour panels has been established. The first group was composed of the first few layers on the striking face. The heavyweight fabrics as heat resistant layers were used in this group to resist the heat generated on the striking face. The second group contained some middle layers close to the last perforated layers. The lightweight fabric was combined in this group due to the higher energy absorption capacity. All back layers were classified into the third group. Dyneema UD laminates were placed in this group to constrain the large transverse deflection of the lightweight fabric and to minimize BFS of the panel. Two hybrid panels were designed and evaluated. In the perforation ballistic tests, the hybrid panel was more likely to stop the projectile compared to Twaron woven panels with the same areal density. In the non-perforation ballistic tests, the hybrid panel exhibited significantly lower BFS and achieved the reductions in weight. Such hybrid design makes best use of different available materials to achieve the improvement of ballistic performance and lightweight of a panel. It has a practical significance for the soft armour panel design.

No description available.

Title: The influence of equipment and arms on skeletal muscles activities while practising direct kick. Aim: The aim of this thesis was to find out the influence of carried equipment and arms on the activity of skeletal muscles when a direct front kick is being practised. The methods used: This thesis has an empirically observational character. Muscular activities were measured by means of surface electromyography synchronised by Qualisys screen system. To obtain statistic data, a t-test has been used, requiring 5 % significance level. Results: While carrying a 15-kilogram load, the activity of skeletal muscles was not significantly reduced when performing a direct front kick. However, a 30- kilogram load caused a substantial reduction of skeletal muscular activities during the kick described above. After adding a 15-kilogram bag to another 15 kilograms in the form of a body armour, a helmet and arms, the muscular activity changed its features in a considerable way. Furthermore, most respondents proved 45-kilogram load to be over their limit. The equipment and arms of that weight led to the summation action potential, exceeding the power- coordinative functional reserve, and thus the deformation of the direct front kick technique. Keywords: close combat, EMG, equipment, arms, direct front kick

A qualitative description of the personal armour design system is elicited by comparing armour throughout the ages. Inputs that 'shape' designs are the materials technology, threat, wearer, task and environment. The emergent properties of protection, ergonomic effectiveness and financial cost form the basis of trade-offs to select final solutions. Work on the protection subsystem refines the key positive emergent property of personal armour. Existing quantifications of protection effectiveness are rejected in favour of a novel measure named the Usefulness Factor, UF. This is the first measure that accounts for the real benefit of armour. A five-stage model is proposed for the assessment of protection. Two feedback loops - due to making tasks as safe as possible and the ergonomic penalty of armour are evident. These must be considered in order to assess protection correctly. Casualty reduction analysis software (CASPER) is used to produce 'approach plots' and 'zones of usefulness' in order to make tasks safer and map the benefit of armour. This approach is demonstrated with the UK's Lightweight Combat EOD Suit against L2A2 and No. 36 Mills grenades, an HB876 area denial mine, a BL 755 sub-munition and a 105mm artillery shell. Assessment of secondary fragmentation from antipersonnel (AP) blast mines defines a threat input that is specific to Explosive Ordnance Disposal (EOD). Trials are carried out with explosive charges of 50g to 500g, buried under 5 or 10cm of stones and sand at a range of 1m. The threat is defined in terms of the probabilities of (a) being hit, (b) a hit perforating armour and (c) a hit incapacitating an unarmoured person. The chances of being hit close to the ground decrease to approximately 15% of the value when directly above the mine. Secondary fragmentation is not likely to perforate armour that protects against primary fragments. However, it is likely to incapacitate an unarmoured person. Protection is traded-off against proxies for ergonomic and financial cost effectiveness by using quantitative optimisation of personal armour. This introduces the concept of a 'protection optimisation envelope', which defines the bounds of possibility rather than a single solution. CASPER is adapted to produce weight and cost as well as incapacitation parameters. This provides a model that generates both benefits and constraints of armour. Hence, the foundations are laid for the world's first fully integrated personal armour design tools. The ergonomic effectiveness subsystem is the primary constraint of personal armour. Visor demisting for the UK's Mk 5 EOD Suit provides a simple example. Existing methods of assessment of the ergonomic penalty of armour are considered. A novel development of biomechanics computational models is proposed to predict both the mechanical and thermal burdens of armour.

A qualitative description of the personal armour design system is elicited by comparing armour throughout the ages. Inputs that 'shape' designs are the materials technology, threat, wearer, task and environment. The emergent properties of protection, ergonomic effectiveness and financial cost form the basis of trade-offs to select final solutions. Work on the protection subsystem refines the key positive emergent property of personal armour. Existing quantifications of protection effectiveness are rejected in favour of a novel measure named the Usefulness Factor, UF. This is the first measure that accounts for the real benefit of armour. A five-stage model is proposed for the assessment of protection. Two feedback loops - due to making tasks as safe as possible and the ergonomic penalty of armour are evident. These must be considered in order to assess protection correctly. Casualty reduction analysis software (CASPER) is used to produce 'approach plots' and 'zones of usefulness' in order to make tasks safer and map the benefit of armour. This approach is demonstrated with the UK's Lightweight Combat EOD Suit against L2A2 and No. 36 Mills grenades, an HB876 area denial mine, a BL 755 sub-munition and a 105mm artillery shell. Assessment of secondary fragmentation from antipersonnel (AP) blast mines defines a threat input that is specific to Explosive Ordnance Disposal (EOD). Trials are carried out with explosive charges of 50g to 500g, buried under 5 or 10cm of stones and sand at a range of 1m. The threat is defined in terms of the probabilities of (a) being hit, (b) a hit perforating armour and (c) a hit incapacitating an unarmoured person. The chances of being hit close to the ground decrease to approximately 15% of the value when directly above the mine. Secondary fragmentation is not likely to perforate armour that protects against primary fragments. However, it is likely to incapacitate an unarmoured person. Protection is traded-off against proxies for ergonomic and financial cost effectiveness by using quantitative optimisation of personal armour. This introduces the concept of a 'protection optimisation envelope', which defines the bounds of possibility rather than a single solution. CASPER is adapted to produce weight and cost as well as incapacitation parameters. This provides a model that generates both benefits and constraints of armour. Hence, the foundations are laid for the world's first fully integrated personal armour design tools. The ergonomic effectiveness subsystem is the primary constraint of personal armour. Visor demisting for the UK's Mk 5 EOD Suit provides a simple example. Existing methods of assessment of the ergonomic penalty of armour are considered. A novel development of biomechanics computational models is proposed to predict both the mechanical and thermal burdens of armour.