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Possibilities of using cold gas dynamic spray (Cold Spray) in military applications
Dvořáček, Jan ; Štěpánek, Roman (referee) ; Řehořek, Lukáš (advisor)
This work aims to acquaint with thermal spray method called Cold spray. This method is used for repair of expensive and badly replaceable components, which are mainly used in aerospace and military branch of industry. These repairs cause economic savings, higher accuracy and quality than other thermal spray methods. There is a possibility to use Cold spray for ballistic armor production. It is possible that ballistic protection would have higher ballistic efficiency, durability and coherence. The second part of the work handle with the evaluation of the interface of a metal-ceramic two-layer ballistic protection system made by the cold spray method. The evaluation was performed in the form of light and electron microscopy.
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Light ceramic materials for ballistic protection
Greguš, Peter ; Pouchlý, Václav (referee) ; Salamon, David (advisor)
This thesis gives a comprehensive characterization of lightweight non-oxide ceramic materials for ballistic applications, an overview of production technologies and processing of boron carbide B4C and its ceramic-based composites. A framework for evaluating the ballistic resistance of the material based on mechanical properties is shown there. It can be used in experiments without normalized equipment. The experiments including B4C + Si, B4C + Ti composites, and application of Spark plasma sintering (SPS) were designed according to outputs from the theoretical part. The volume fractions of Si, Ti dopants were optimized based on ongoing chemical reactions during sintering. The obtained samples were subjects of mechanical testing which results were compared to identify the ideal ratio of matrix and reinforcement. As the best suited material for ballistic protection, B4C + 1,0 obj. % reaches these values of parameters; hardness = 3502 ± 122 HV1; fracture toughness KIC = 2,97 ± 0,03 MPam^0,5.
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Ballistic-Proof Concretes
Koutný, Ondřej ; Bílek,, Vlastimil (referee) ; Keršner, Zbyněk (referee) ; Ptáček, Petr (advisor)
Doctoral thesis „Ballistic-proof concretes“ deals with description, design and development of material based on ultra-high performance fibre reinforced cementitious composite with increased ballistic resistance i.e. increased resistance against high-strain rate dynamic loading induced by interaction of high-velocity moving objects. High mechanical properties, essential for such a material, are reached especially by maximal reduction of water-to-binder coefficient using high-range water reducing agents, high-strength aggregates and dense structure by precise selection and dosage of raw materials in the recipe. The main goal is to prepare a methodology for design of such a materials, observation of material behaviour on ballistic loading and quantitative description of material response for protective structures design. Properties of designed materials within this thesis are comparing with properties of commercially available and commonly used cementitious composites in order to create a concept for material limits in the field of ballistic protection. This concept enables to estimate ballistic protection of present or newly-designed materials and structures.
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Effect of shooting stances on ballistic protection of the shooter
Zdražila, Václav ; Barták, Erik (advisor) ; Kubový, Petr (referee)
Title Effect of shooting stances on ballistic protection of the shooter Objectives The goal of this thesis is to develop a method which could measure ballistic protection, which is currently provided by a bulletproof vest to the shooter in a current shooting stance. This work also focuses on analysis of the currently used shooting techniques and shooting stances, comparison of protection they can provide, and last but not least, to fill the gap in literature, wich deals with this issue. Methods This is an empirical thesis of observational character. Shooting stances were tested on a camera system named Qualisys. The results were first processed by a program for 3D analysis, and the ballistic protection provided by the bulletproof vest in different positions was calculated in a program for 3D modeling. Results: From the measured data, it was found that changing targets to the left (for right- handed) the provided ballistic protection significantly changes to worse. Conversely, when changing targets to the right, the ballistic protection faired the same or slightly better than aiming forward. The worst results of all stances came from the side shooting stance in which the bulletproof vest provided almost no protection. Keywords Ballistic protection, shooting stances, Qualisys, 3d analysis, vital zone
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