Part importante de l’armement préhistorique pour les périodes récentes (quantitativement et qualitativement), l’archerie représente un objet d’étude riche en développements problématiques. A l’aube de l’introduction progressive de la métallurgie dans les usages techniques, il est intéressant de saisir le ou les processus de transferts mis en œuvre. Transition chronologique (Néolithique/Age du bronze), transition matérielle (types de pièces produites et types de matériaux employés) et transition comportementale sont ainsi envisagées pour parvenir à préciser le statut de cet armement dans les sociétés concernées. En nous basant sur la caractérisation de la panoplie de l’archer, sur l’identification des contextes de fabrication, sur la reconnaissance des champs fonctionnels (utilisations et usagers) et sur l’analyse archéo-balistique des vestiges de traumatismes par flèches dans le cadre de violences interhumaines, il en résulte un ensemble exhaustif qui renouvelle sensiblement la perception de cet armement dans le temps et dans les usages. / For recent prehistory, the archery represents one of the main components of weaponry and, for this reason, it is interesting to examine its impact on societies. At the dawn of the progressive introduction of the metal industry in the technical uses, understanding the process of transfer or implemented is of major interest. Transition time period (Neolithic / Bronze Age), material transition (types of parts produced and types of materials used) and behavioral transition are thus considered for specifying the weapons status in the concerned societies. Here based on the characterization of the archer display, the identification of manufacturing contexts, the recognition of functional fields (uses and users) and the analysis of archaeological remains of ballistic arrow trauma in interpersonal violence contexts, we propose a new recovery of this research field, improving significantly our knowledge and apprehension of these weapons in both time and uses.

Approved for public release; distribution is unlimited / In the boost phase interception of ballistic missiles, determining the exact position of a ballistic missile has a significant importance. Several sensors are used to detect and track the missile. These sensors differ from each other in many different aspects. The outputs of radars give range, elevation and azimuth information of the target while space based infrared sensors give elevation and azimuth information. These outputs have to be combined (fused) achieve better position information for the missile. The architecture that is used in this thesis is decision level fusion architecture. This thesis examines four algorithms to fuse the results of radar sensors and space based infrared sensors. An averaging technique, a weighted averaging technique, a Kalman filtering approach and a Bayesian technique are compared. The ballistic missile boost phase segment and the sensors are modeled in MATLAB. The missile vector and dynamics are based upon Newton's laws and the simulation uses an earth-centered coordinate system. The Bayesian algorithm has the best performance resulting in a rms missile position error of less than 20 m. / 1st Lieutenant, Turkish Air Force

The first objective of this thesis is to investigate the effect of several forms of electronic attack (EA) on the radio frequency (RF) sensors used within a boost-phase ballistic missile intercept system. The EA types examined include noise jamming, chaff, radar cross section (RCS) reduction, and expendable decoys. Effects of the EA methods are evaluated by examining the track position error at the sensor fusion output. Sensor fusion architectures investigated include a weighted average sensor fusion; Kalman-filter-based sensor fusion, and joint probabilistic data fusion architecture. A second objective of this thesis is to extend the single-target, single-interceptor analysis and simulation to a multi-target, multi-interceptor scenario to include the formation of an ellipsoidal gating process to correctly correlate the target measurements with the corresponding track file. We show that the most effective EA is the use of noise jamming followed by a RCS reduction of the missile body. We also show that a properly designed sensor fusion process can effectively mitigate the EA techniques that might be used in a boostphase intercept scenario.

Doctor of Philosophy / Department of Mechanical and Nuclear Engineering / Youqi Wang / Ballistic performance of textile fabric is affected by numerous elements, such as fabric architecture, material property, and projectile characteristics. Near fiber-level microstructures of soft body armor composed of multi-layer Kevlar KM-2 fabrics are generated for numerical simulation. The modified digital element approach (DEA) is applied to determine the ballistic limit of textile fabrics against fragment simulating projectiles (FSP). Different from other numerical models, the DEA takes a considerable amount of fiber-level detail into consideration and models the fabric at filament-level. In this approach, fabric is an assembly of yarns weaved and relaxed into pre-arranged pattern; yarn is simulated as a bundle of digital fibers. When the number of digital fibers per yarn reaches the number of actual fibers per yarn, fiber-level simulation is achieved. The DEA model successfully simulates real scale multi-layer fabric impacted by spherical projectile and accurately predicted fabric displacement and failure mechanism. It was assumed that the digital fiber is fully flexible and its bending rigidity is negligible. Shear force was thus neglected. However, for projectiles with sharp edge(s), such as FSP, due to resultant shear force, fabric failure starts where it interacts with projectile edge. As a result, the numerical results derived from the previous DEA overestimated the impact strength of fabrics against projectiles with shape edges. Therefore, shear force and fiber bending rigidity must be considered. In the modified DEA approach, numerical tests are employed to determine the effective bending rigidity of digital fiber. A combined tension-shear failure model is then incorporated into the DEA in order to calculate the shear force applied to fibers. The 3-D microscope is applied to measure the radius of FSP along the edge. The surface of the FSP is meshed into triangle elements. A unique algorithm is developed and employed to search contacts between textile fabric and projectile of arbitrary shape. In this research, first, an overview of ballistic impact analysis is discussed; the previous DEA model used in simulating ballistic impact and penetration process is presented. Second, the modified DEA approach used in simulating arbitrary shape projectile perforation process is established and verified. The method of searching and calculating contacts between textile fabric and solid body projectile is explained. The convergence and accuracy of digital element mesh are investigated statistically using tension-shear failure model. Third, fabric shear force and fiber bending rigidity are investigated using tension-shear failure model. The effective digital fiber area moment of inertia is numerically determined. Fourth, standard ballistic tests of real scale multi-layer Kevlar KM2 fabrics are simulated using FSP. Numerical results are compared to high-resolution experimental test data. The modified DEA is validated.

The present research aims at engineering design of military helmet shells with continuous 3D woven fabric reinforcements for improved protection at a lighter weight and a reduced cost. The research was carried out using both the experimental and numerical methods. The results proved that the designed 3D woven wadded through-the-thickness angle interlock (TTAI) fabrics can be successfully moulded as continuous reinforcements for the doubly curved military helmet shells; therefore, costs in pattern cutting in the current composite helmet making process are eliminated. An improved ballistic performance was also demonstrated in the continuously reinforced composite structures. The wadding yarns added into the conventional TTAI fabrics enhanced the mechanical properties along the warp direction significantly. Improved composite in-plane isotropy was achieved by using the wadded TTAI fabrics as reinforcements. The locking angle method was modified based on the deformation behaviour of TTAI fabrics and was used to predict and evaluate the mouldability of both conventional and wadded TTAI structures. Mouldability factor, defined from the locking angle, assists the design and selection of continuous reinforcements that are of the appropriate mouldability. The mouldability limit of a PASGT (Personnel Armour System for Ground Troops) helmet shell was determined as 25.54. Thus, TTAI fabrics with mouldability factor no larger than this value are capable of continuously reinforcing the doubly curved shape. Ballistic tests and post-mortem examinations through ultrasonic C-scan and X-ray computed tomography (CT) demonstrated the advantages of the continuously reinforced composite in energy absorption. Up to 19.3% more of the kinetic energy was absorbed by the continuously reinforced panel through generating a delamination volume that was twice as large as that of the discontinuously reinforced one, and the delamination damages were distributed over a wider area. Under the same level of fabric mouldability and composite areal density, the panels reinforced with fewer plies of heavier fabrics performed better. The wadded TTAI reinforced composite panel demonstrated the optimal ballistic resistance by showing a 25.5% thickness increase and 55.3% penetration through the thickness. The 3D wadded fabric and 2D plain weave fabric continuously reinforced flat panels presented an equivalent ballistic performance. Meanwhile, further numerical analyses were conducted based on the digitally obtained geometry of a PASGT helmet. Although the ballistic limits varied from location to location, an equivalent ballistic limit of the helmet shell was noticed for the PASGT shell when compared to its flat counterparts. The military helmet shells reinforced by 3D wadded TTAI fabrics continuously offer improved ballistic performance. This is attributed to the preserved reinforcement continuity and the enhanced through-the-thickness properties. The research provides a novel reinforcing strategy for the construction of future composite military helmet shells.

Abstract Since being developed in 1956, no matter it¡¦s category, function or quantity, Chinese ballistic missiles have kept renewing and increasing. For example, the development of its strategic missiles has undergone the 1st through the 3rd generation with models from Dongfeng-1 to currently developing Dongfeng-41 Ballistic Missile, and its warhead has been gradually developed from carrier of single nuclear head to combination of both traditional and nuclear warheads and to multiple warheads now. Under such multiple developments, Chinese nuclear strategy according to their official speech has still adopted ¡§minimum deterrence¡¨ claimed by the 1960¡¦s and 1970¡¦s until now, and which has already led to external speculations. They think that Chinese has devoted to modernization of ballistic missiles lately, actively developed more land-based strategic missiles and sea-based nuclear submarines, techniques of multiple warheads and space-based weapons, and reinforced the practicality of tactical nuclear missiles etc. that such development has already exceeded the ¡§minimum deterrence¡¨ strategy, which even develops towards the ¡§limited deterrence¡¨ strategy. Therefore, whether China¡¦s deterrence strategy is changing is one of the assumptions in this study. If China¡¦s deterrence strategy is no longer equipped with the minimum deterrence, then whether the most important features of the minimum deterrence by ¡§no use of nuclear weapons at first¡¨ and China¡¦s¡§three nos principle on nuclear weapons¡¨will be changed accordingly is the second assumption in this study. Chinese ballistic missiles apart from being used as deterrence can also be used to practice coercive and annihilative strategies. Especially in the issue of Taiwan, when Chinese deterrence strategy fails in terms of Taiwan, it may use coercive or annihilative strategies to achieve their political and military objectives. As the ability of Taiwan¡¦s anti-ballistic missile is obviously insufficient; so if Taiwan suffers the attack from Chinese missiles, the result will be unimaginable. Therefore, how to prevent the attack from its missiles is what I would like to discuss in this paper. For the probable battle by the two sides of the Taiwan Strait in the future, in order to quickly facilitate the victory, whether Chinese will use micro-kiloton nuclear warhead to destroy the important and stable military targets in Taiwan to help smooth the warfare and further crash the myth that Chinese will not use nuclear weapons against Taiwan is the 3rd assumption in this paper. Finally how to increase our defense against ballistic missiles and whether we should participate in the TMD (Theatre Missile Defense) provided by America, I will provide several suggestions for references of the related units, hoping to make certain contributions towards Taiwanese prevention against the threat from Chinese ballistic missile.

Thesis (M.A. in National Security Affairs)--Naval Postgraduate School, September 2003. / Thesis advisor(s): James Russell, Peter R. Lavoy. Includes bibliographical references (p. 69-79). Also available online.

Thesis (M.A. in National Security Affairs)--Naval Postgraduate School, June 2003. / Thesis advisor(s): David S. Yost, James J. Wirtz. Includes bibliographical references. Also available online.

In the last several decades the number of the fatalities related to criminally inflicted cranial gunshot wounds has increased (Aarabi et al.; Jena et al., 2014; Mota et al., 2003). Back-spattered bloodstain patterns are often important in investigations of cranial gunshot fatalities, particularly when there is a doubt whether the death is suicide or homicide. Back-spatter is the projection of blood and tissue back toward the firearm. However, the mechanism of creation of the backspatter is not understood well. There are several hypotheses, which describe the formation of the backspatter. However, as it is difficult to study the internal mechanics of formation of the backspatter in animal experiments as the head is opaque and sample properties vary from animal to animal. Performing ballistic experiments on human cadavers is rarely not possible for ethical reasons. An alternative is to build a realistic physical 3D model of the human head, which can be used for reconstruction of crime scenes and BPA training purposes. This requires a simulant material for each layer of the human head. In order to build a realistic model of human head, it is necessary to understand the effect of the each layer of the human head to the generation of the back-spatter. Simulant materials offer the possibility of safe, well‐controlled experiments. Suitable simulants must be biologically inert, be stable over some reasonable shelf‐life, and respond to ballistic penetration in the same way as the responding human tissues. Traditionally 10-20% (w/w) gelatine have been used as a simulant for human soft tissues in ballistic experiments. However, 10-20% of gelatine has never been validated as a brain simulant. Moreover, due to the viscoelastic nature of the brain it is not possible to find the exact mechanical properties of the brain at ballistic strain rates. Therefore, in this study several experiments were designed to obtain qualitative and quantitative data using high speed cameras to compare different concentrations of gelatine and new composite material with the bovine and ovine brains. Factors such as the form of the fragmentation, velocity of the ejected material, expansion rate, stopping distance, absorption of kinetic energy and effect of the suction as well as ejection of the air from the wound cavity and its involvement in the generation of the backspatter have been investigated. Furthermore, in this study a new composite material has been developed, which is able to create more realistic form of the fragmentation and expansion rate compared to the all different percentage of the gelatine. The results of this study suggested that none of the concentrations the gelatine used in this study were capable of recreating the form of the damage to the one observed from bovine and ovine brain. The elastic response of the brain tissue is much lower that observed in gelatine samples. None of the simulants reproduced the stopping distance or form of the damage seen in bovine brain. Suction and ejection of the air as a result of creation of the temporary cavity has a direct relation to the elasticity of the material. For example, by reducing the percentage of the gelatine the velocity of the air drawn into the cavity increases however, the reverse scenario can be seen for the ejection of the air. This study showed that elastic response of the brain tissue was not enough to eject the brain and biological materials out of the cranium. However, the intracranial pressure raises as the projectile passes through the head. This pressure has the potential of ejecting the brain and biological material backward and create back-spatter. Finally, the results of this study suggested that for each specific type of experiment, a unique simulant must be designed to meet the requirements for that particular experiment.

The high strength, light weight, and flexibility of fabric protection systems makes them the preferred solution for a number of ballistic applications. Examples include body armor, fan blade containment for jet engines, and orbital debris shielding. In general, these protection systems employ plain woven fabric, most suitable for flat or gently curved geometries. Highly curved surfaces, such as personnel extremities, may be more effectively protected using fabrics of different weaves. This dissertation presents the first numerical model developed to simulate ballistic impacts into plain, harness satin, twill, and basket weave fabrics. It extends previous work on hybrid particle-finite element methods developed for fabric modeling. The extended formulation closely replicates the tensile load response and contact-impact dynamics of highly flexible yarns, by generalizing the kinematic model and density interpolation used in previous work. The formulation has been validated in three dimensional simulations of impact experiments conducted to investigate the effects of weave type on fabric ballistic performance. / text