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Ballistic Design Optimization Of Three-dimensional Grains Using Genetic AlgorithmsYucel, Osman 01 September 2012 (has links) (PDF)
Within the scope of this thesis study, an optimization tool for the ballistic design of three-dimensional grains in solid propellant rocket motors is developed. The modeling of grain geometry and burnback analysis is performed analytically by using basic geometries like cylinder, cone, sphere, ellipsoid, prism and torus. For the internal ballistic analysis, a quasi-steady zero-dimensional flow solver is used. Genetic algorithms have been studied and implemented to the design process as an optimization algorithm. Lastly, the developed optimization tool is validated with the predesigned rocket motors.
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The flow of a compressible gas through an aggregate of mobile reacting particles /Gough, P. S. (Paul Stuart) January 1974 (has links)
No description available.
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Pirotechninio vamzdžio hidrodinaminių procesų tyrimai / Research of powder-actuated hidrodynamic processes in pyrotechnic tubeŽitkovskis, Dmitrijus 17 June 2014 (has links)
Baigiamajame magistro darbe teoriškai tiriami statybinio parakinio įrenginio vidinės balistikos hidrodinaminiai ir termodinaminiai procesai. Be to, modeliuojami garso slopintuvai ir teoriškai tiriamas jų efektyvumas. Darbe padarytos vidinės balistikos, kaip mokslo, statybinių viniašaudžių ir garso slopintuvų tipų apžvalgos. Atliktas skaitinis vidinės balistikos ir dujų plėtimosi procesų modeliavimas. Pateikti modeliavimo rezultatai ir jų analizė. / The topic of Master thesis is research of powder-actuated hydrodynamic ant thermodynamic processes in pyrotechnic tube. Also were made 3d models of suppressors and modeled their effectiveness. Internal ballistics, powder-actuated tools and suppressors reviews were made. Performed calculations of internal ballistics and gas extension processes. Presented results and analysis.
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Time-dependent effects of human blood on the microscopic comparison of fired bulletsArendse, Wayne E. 31 May 2008 (has links)
This dissertation consists of five chapters, each of which focuses on various aspects of the forensic discipline of Firearms and Toolmarks. This dissertation for the most part attempts to highlight the exposure of projectiles to blood and the degradation over time of the fine detail, which is necessary for microscopic examination. This study should be of interest to students and qualified role-players in forensic science, the criminal justice system, the law community and the general population globally.
Chapter 1 identifies the research problem and the necessary steps that were taken to ensure that the research methodol.ogy applied is relevant and reliable. Chapter 2 focuses on various factors that have to be considered in damage to bullets and investigation procedures that should be followed to ensure that physical evidence is preserved for submitting to a forensic science laboratory.
Chapter 3 investigates the degradation effects of fired bullets exposed to various materials in a laboratory environment and the timelines associated with the degradation effects. Chapter 4 evaluates the examination procedures for fired bullets and the contributing factors that may influence the striation marks on bullets needed for microscopic examination. It also examines the scientific method used for firearm identification, and explores the admissibility of physical evidence in a court of law. The final chapter, Chapter 5 discusses the findings and recommendation of this research study. / Criminology and Security Science / M. Tech. (Forensic Investigation)
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The flow of a compressible gas through an aggregate of mobile reacting particles /Gough, P. S. (Paul Stuart) January 1974 (has links)
No description available.
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An engineering approach to modelling ballistic impact on hybrid polymer laminatesBanan, Roshan, Aerospace, Civil & Mechanical Engineering, Australian Defence Force Academy, UNSW January 2009 (has links)
Hybrid polymer laminates of polycarbonate and PMMA have generated considerable interest among researchers as an alternative to traditional glass armours because of their potential for reduced cost and weight. Generally, the development of ballistic armour is carried out experimentally which is an expensive task in terms of time and cost. Numerical simulation provides a much greater facility to understand the phenomenon of ballistic impact and the effects of various parameters on the response to such impact. In addition it provides an easy means of comparing the impact performance of different materials as well as combination of materials forming hybrid laminates. The aim of this research was to develop a numerical modelling capability to simulate the ballistic response of hybrid polymer laminates, specifically polycarbonate and PMMA, using a commercially available finite element code LS-DYNA. The challenge was to work within the limitations of the material models and the failure algorithms available within LS-DYNA, and still try to reproduce the behaviour observed experimentally by previous researchers, initially on monolithic plates of polycarbonate and PMMA and then on hybrid laminates. The first part of the study focuses on a detailed literature survey on mechanical and dynamic characterisation of polycarbonate and PMMA as well as experimental and numerical studies previously conducted on ballistic behaviour of these materials as well as their combinations. The material properties of the polymers compiled from this literature survey were used as input for the selected LS-DYNA material model. Impact simulations were carried on monolithic and laminated media of polycarbonate and PMMA and where possible these were compared to experimental results. It was observed that the results agreed with the experimental data qualitatively. Quantitatively the results showed some discrepancies which were attributed to the limitations faced in simulating the exact test conditions numerically. Numerical simulations were carried out to study the effects of variations in laminate thickness and plate support diameters as well as to examine the influence of the bond between the layers. Finally the impact response of four different combinations of polycarbonate and PMMA are compared to each other for different laminate thicknesses.
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Dynamique des tubes parcourus à grande vitesse : influence de la géométrie des tubes et leur environnement sur la justesse et la dispersion / Dynamic of tubes crossed by high speed projectiles : influence of tube and weapon geometry on accuracy and dispersionLiennard, Mathilda 16 October 2015 (has links)
La précision de tir d’une arme dépend de nombreux facteurs intervenant aux différentes étapes du parcours de la munition (balistique intérieure, intermédiaire et extérieure). Certains travaux ont démontré l’importance de l’influence de la phase de balistique intérieure, pendant laquelle la munition traverse le tube, sur les résultats à la cible. En effet, c’est cette phase qui détermine les conditions de sortie du tube de la munition et par conséquent son comportement au cours du vol. Les conditions d’entrée du projectile, la géométrie du tube et de l’arme, et les mouvements de ces derniers au cours du tir, sont autant de paramètres pouvant modifier l’interaction tube/projectile et ainsi entraîner un changement des vitesses angulaires et de translation de la munition au moment du largage. Cette étude a donc pour but de mettre en exergue les paramètres géométriques de l’arme et du tube qui influencent la justesse et la dispersion. Une analyse statistique a été réalisée à partir de la base de données des résultats de tir du 25 mm. Elle a permis de mettre en évidence l’influence de plusieurs paramètres dont la rectitude du tube. Par la suite, des essais ont été conduits en appareil de tir dans le but d’isoler la part de la géométrie du tube sur les écarts à la cible et ainsi de confirmer la contribution de la rectitude. Un modèle numérique tridimensionnel a été développé afin de faire varier ce paramètre et d’étudier son influence sur le comportement de la munition en phase de balistique intérieure. La représentativité du modèle a été vérifiée à l’aide d’accéléromètres embarqués dans la munition. Ces tirs ont nécessité le développement d’une solution innovante optoélectronique afin de transmettre les accélérations en temps réel. Les résultats expérimentaux obtenus ont permis de constater que les accélérations de la munition modélisée étaient représentatives. Le modèle permet maintenant de réaliser des études paramétriques et de déterminer les profils de tube les plus pénalisants pour la précision de tir. / Gun accuracy is influenced by several factors during the stages of the ammunition course (internal, intermediate and external ballistics). According to previous studies, internal ballistics are the major contributor to deviations from target. Indeed, this phase determines projectile exit conditions and, consequently, his behavior during the flight. The projectile entry conditions, the weapon and barrel geometry and their movements during firing, can modify the interaction tube / projectile and change ammunition angular rates and its transversal velocities. The purpose of this thesis is to determine the parameters related to barrel and gun geometry, which influence the bias and the dispersion. A statistical analysis was led thanks to the data base of the 25 mm firing results. It was found that some parameters, including barrel straightness, affect accuracy. Subsequently, tests were conducted with a firing appliance in order to isolate the barrel geometry influence on the deviations from the target and to confirm the straightness impact. A tridimensional numerical model was created in order to vary this parameter and to study its influence on the ammunition behavior during internal ballistics. The representativeness of the model was validated using accelerometers embedded in the ammunitions. The firing of these ammunitions has required the development of an optoelectronic system to transmit accelerations in real time. The comparison between experimental and numerical results has shown close amplitudes and similar shapes curves that proves the representativeness of the model. The model can be used now to lead parametric analysis and to determine the straightness shapes the most penalizing for gun accuracy.
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Comparison of gunshot entrance morphologies caused by .40-caliber Smith & Wesson, .380-caliber, and 9-mm Luger bullets = a finite element analysis study = Comparação de morfologias de orifícios de entrada causados por projéteis de calibre .40 Smith & Wesson, calibre .380, e 9 mm Luger: estudo com análise de elementos finitos / MatComparação de morfologias de orifícios de entrada causados por projéteis de calibre .40 Smith & Wesson, calibre .380, e 9 mm Luger : estudo com análise de elementos finitosMatoso, Rodrigo Ivo, 1978- 24 August 2018 (has links)
Orientador: Felippe Bevilacqua Prado / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-24T15:43:44Z (GMT). No. of bitstreams: 1
Matoso_RodrigoIvo_M.pdf: 5791267 bytes, checksum: 01cfe26513615d72227501ff1a54a3c2 (MD5)
Previous issue date: 2014 / Resumo: Armas de fogo podem causar feridas fatais e serem identificadas pelos vestígios deixados no corpo ou em torno deste. Entretanto, há casos em que nem projétil e nem arma do delito estão dispostos no local de crime. Estudos balísticos envolvendo modelos de elementos finitos podem reproduzir condições biomecânicas computacionais, sem ferir princípios bioéticos, pois não ocorrem testes diretos em animais ou em seres humanos. O objetivo deste estudo é comparar as morfologias de orifícios de entrada causados por projéteis calibre .40 Smith & Wesson (S&W), calibre .380 e calibre 9x19 mm Luger. Um projétil .40 S&W encamisado total, um projétil .380 encamisado total e um projétil 9x19 mm Luger encamisado total foram computacionalmente disparados contra região de glabela do modelo de elementos finitos, à distância de 10 cm, com incidência perpendicular ao ponto do alvo. Os resultados apresentam diferentes morfologias nos orifícios de entrada produzidos pelos três projéteis, utilizando-se o mesmo modelo de crânio e na mesma distância de tiro. Os resultados e as características dos orifícios de entrada foram discutidos. Modelos de elementos finitos permitem pesquisas balísticas computacionais praticáveis, que podem ser úteis para peritos forenses quando da comparação e análise de dados relacionados a feridas por arma de fogo na região frontal do crânio / Abstract: Firearms can cause fatal wounds, which can be identified by traces on or around the body. However, there are cases where neither the bullet nor gun is found at the crime scene. Ballistic research involving finite element models can reproduce computational biomechanical conditions, without compromising bioethics, as they involve no direct tests on animals or humans. This study aims to compare the morphologies of gunshot entrance holes caused by .40-caliber Smith & Wesson (S&W), .380-caliber, and 9x19-mm Luger bullets. A fully metal-jacketed .40 S&W projectile, a fully metal-jacketed .380 projectile, and a fully metal-jacketed 9x19-mm Luger projectile were computationally fired at the glabellar region of the finite element model from a distance of 10 cm, at perpendicular incidence. The results show different morphologies in the entrance holes produced by the three bullets, using the same skull at the same shot distance. The results and traits of the entrance holes are discussed. Finite element models allow feasible computational ballistic research, which may be useful to forensic experts when comparing and analyzing data related to gunshot wounds in the forehead / Mestrado / Odontologia Legal e Deontologia / Mestre em Biologia Buco-Dental
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[en] DEVELOPMENT OF METHODOLOGY FOR CALIBRATING PIEZOELECTRIC TRANSDUCERS USED IN INTERNAL BALLISTICS FOR TRANSIENT PRESSURE MEASUREMENTS / [pt] DESENVOLVIMENTO DE METODOLOGIA DE CALIBRAÇÃO DE TRANSDUTOR PIEZELÉTRICO DE PRESSÃO UTILIZADO EM BALÍSTICA INTERNAALFREDO JORGE BAHIA HEINE 30 December 2004 (has links)
[pt] A presente pesquisa de mestrado, de interesse da indústria de armamento, mais especificamente no controle de qualidade de lotes de munição, relaciona-se com o desenvolvimento de metodologia para calibração de transdutor piezelétrico para medição de pressão transiente cuja duração é da ordem de
milisegundos. Como sua principal contribuição, o trabalho disponibiliza metodologia própria de calibração ainda não disponível no País, atribuindo confiabilidade a medições realizadas em fenômenos associados ao que se denomina balística interna, que se constitui no estudo científico dos processos que ocorrem no interior de uma arma de fogo a partir do instante de iniciação (ignição) do propelente. Não obstante a faixa de pressão estudada, de 34,7 a 349,8 bar), ser baixa se comparada com as pressões desenvolvidas na balística interna, que podem até superar 6000 bar, a simples substituição do gerador de pressão por outro de maior capacidade é suficiente para a calibração numa faixa mais larga utilizando-se a mesma metodologia. O complexo processo de balística interna foi simulado em condições laboratoriais pela submissão brusca do sensor piezelétrico, objeto da calibração, originalmente montado em uma câmara diminuta (cerca de dez vezes menor que o volume total de fluido pressurizado) de óleo à pressão atmosférica, a um pico de pressão induzido pela comunicação da câmara a uma linha de óleo pressurizada à pressão de calibração pré-determinada através de uma bomba hidráulica, pressão esta que caracteriza um ponto de calibração. Complementando o aparatus experimental utilizado para simular o fenômeno da balística interna, foi utilizado um sistema de medição com tempo de resposta compatível (rise time < 5 us) à ordem de grandeza da duração do fenômeno estudado. O aparatus experimental utilizado é tal que permite alterar a duração desses eventos por meio de uma válvula de restrição, o que resultou em eventos com duração de 2 a 2200 ms. O monitoramento do sinal de resposta do transdutor piezelétrico no curso da calibração realizada permite estabelecer o tempo-limite associado ao qual o sinal mantém-se isento de indesejável atenuação, considerada fonte de erro na medição de pressão. O processo de calibração desenvolveu-se para 10 pontos distintos, perfazendo um total de 340 experimentos (variando-se o transiente de pressão imposto ao transdutor), monitorando-se o sinal de resposta do transdutor contra
o valor da pressão medida por um manômetro calibrado pelo laboratório de pressão da PUC-Rio, credenciado pelo INMETRO e, portanto, assegurando rastreabilidade das medições ao Sistema Internacional de Unidades. Alterações no aparatus experimental permitem que calibrações usualmente
realizadas em regime de pressurização sejam também realizadas em regime de despressurização, viabilizando, dentre outras análises possíveis, o estudo de estabilidade e histerese do sinal do transdutor. O método experimental desenvolvido não apenas mostrou-se tecnicamente viável e adequado às condições laboratoriais da faixa de pressão na qual foi validado (34,7 a 349,8 bar), como também se
mostrou viável economicamente. A incerteza associada a esse método, obviamente, é maior que aquela obtida com uma balança de peso morto, que se baseia num método primário. A incerteza associada ao método de calibração desenvolvido no presente trabalho de pesquisa pode ser diminuída se for
usado um sistema de medição de tensão com melhor exatidão. / [en] The current research, of armaments industry s interest, more specifically in the quality control of ammunition lots, is related to the development of methodology for calibrating piezoelectric transducers for
transient pressure measurements associated with events whose duration is of the order of milliseconds. As its main contribution, this work presents proper methodology, not available yet in the Country, to ensure reliability to measurements of pressure in internal ballistics, which is the scientific study of the operating
processes within the gun from at the moment when the burning process of the propellant is initiated. In spite of the low transient pressure range studied, 34,7 to 349,8 bar, when compared with the pressures developed in internal ballistics, up to 6000 bar, the simple replacement of the pressure generator for another one of larger capacity is enough to allow for calibration in a wider pressure range using the same methodology. The complex process associated to internal ballistics was simulated in laboratorial conditions by the abrupt exposure of the piezoelectric sensor, object of the calibration, planned and originally mounted in a small oil chamber (about ten times smaller than the total volume of fluid pressurized) maintained at atmospheric pressure, to a pressure peak introduced by the communication of the small chamber to a line of oil pressurized at a desired calibration pressure level by means of a hydraulical pump used to feed the oil system. Each calibration pressure condition corresponds to what is called a calibration point. Complementing the experimental apparatus used to simulate the phenomenon of the internal ballistics, an adequate measurement system (rise time < 5 us, therefore adequate to the time duration of the studied phenomenon) was used. The experimental apparatus employed is such that the time duration of the events could be changed by means of a restriction valve, allowing events with duration from about 2 to 2200 ms. Within the calibration process, the monitoring of the piezoelectric transducer output signal allowed for establishing a specific time-limit to ensure that the signal remained exempt of undesirable attenuation, considered a source of error in the measurement of the transient pressure. The calibration
process was developed for 10 distinct points, totalizing 340 experiments (varying the transient pressure
to which the transducer is exposed), monitoring the output signal of the transducer against the value of the pressure measured with a manometer calibrated in the accredited pressure laboratory of PUC-Rio, traceable to the national standard maintained by the Brazilian National Metrology Laboratory (INMETRO) and, therefore, ensuring overall traceability of measurements to the International System of Units (SI).
Modifications introduced in the experimental apparatus used allow that calibrations usually carried out under a regime of pressurization may also be carried out under a regime of unpressurization, making
possible other studies such as stability and hysteresis of the transducer s output signal. From the technical point of view the experimental method proved to be feasible and suitable to the laboratorial conditions for
the pressure range to which it was validated (34,7 to 349,8 bar). It also revealed economically viable.
Although validated, the uncertainty associated with the proposed method, obviously is greater than the uncertainty associated with a dead weight tester, which is based on a primary method. However, the
uncertainty associated with the method of calibration herein proposed can be minimized whenever a more
accurate voltage measurement system is used.
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Vývoj a aplikace výpočtového modelu balisticky odolného vrstveného laminátu / Development and application of computational model of ballistic resistant composite laminateUrbášek, Jan January 2020 (has links)
This master thesis is aimed at computational modeling of ballistic resistant layered laminate. The introductory sections of the thesis are aimed at understanding the individual topics that are closely related to the interaction of the projectile and target and computational modeling of this process. The main goal of this thesis was to create a computational model that is able to reflect the behavior of aramid fabric during the interaction with the projectile. During the development of the computational model were used more methods of modeling and also more material models were used. For the purposes of the development of the computational model were used the available data of the companies SVS FEM s.r.o. and VVÚ s.p. The outcome of the diploma thesis is a computational model of aramid fabric which is designed for ballistic protection simulations. This model is validated on the basis of available experiments. The validated computational model is then applied to the simulation of ballistic protection.
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