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Analysis of the mechanical properties of plastic parts realized by 3D printing
Krejbychová, Adéla ; Benešovský, Marek (referee) ; Vosynek, Petr (advisor)
This bachelor thesis deals with the analysis of mechanical quantities of PET-G samples which were created by using 3D printing. The problem was solved experimentally. The samples were printed by using the FDM technology (Fused Deposition Modeling). Mechanical properties were measured by the tensile test and the measured quantities were further analyzed statistically. The influence of the pigment, the material manufacturer and the effect of setting the process parameters on the actual construction of the samples were investigated. On the basis of the carried out analyses it was discovered that the samples printed horizontally in the XY plane with a 45° / -45° fill angle from Devil Design had the best mechanical properties.
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Mechanical properties of glass fibers
Ševnina, Marija Vladimirovna ; Svěrák, Tomáš (referee) ; Čech, Vladimír (advisor)
The bachelor thesis deals with the examination of mechanical properties of unsized glass fibers and commercially sized glass fibers. The main objective is to determine the tensile strength, modulus of elasticity, and ductility for the fibers depending on the surface modification. To determine these properties, fiber diameters were measured using an Olympus BX 50 optical microscope followed by a tensile test on the Universal Testing Machine, ZWICK / Z010 / TH2A.
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Properties of adhesive bonds filled with microparticle fillers
Habrová, Karolína ; Valášek, Petr (advisor) ; Müller, Miroslav (referee)
This thesis deals with the measuring of adhesive and cohesive characteristics of composite systems filled with microparticles of glass powder.
The theoretical part describes in detail composites from their historical development
to the present, also their characteristics, general properties, distribution and types of fibers
and matrices. Emphasis is placed on composites filled with particulate filler and current researches in the field of composites with glass filler. Furthermore, the adhesion and cohesion of filled systems is described.
The experimental part of this thesis includes a methodology, which describes in detail
the used materials, methods of preparation of mechanical testing and statistical analysis. The results of mechanical tests for all three composite mixtures and evaluation of cost savings are appended to this thesis.
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The study of the influence of the composition of the lightweight fiber concrete physical and mechanical properties
Šindelek, David ; Bodnárová, Lenka (referee) ; Hela, Rudolf (advisor)
This bachelor thesis deals with a study of light construction concrete with an addition of steel fibre which monitors its impact of the physical mechanical properties. The work is divided into two parts, theoretical and practical. The theoretical part is focused on characteristics and a design of light concrete within the class 35MPa and over with the density within the class of D1,8. Furthermore, it focuses on the increase of toughness of cementitious composites with the form of application of steel fibre in different doses and lengths. In the practical part, formulas of two strength classes 35/38 D 1,8 and 45/50 D1,8 were designed with the help of the steel fibre Krampeharex in doses of 25 and30 kg/m3, and where there were both its impact of the working diagram as well as the compressive strength monitored for the duration of twenty-eight days
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Analýza jakosti „Cold Metal Transfer“ svarů
Polák, Vojtěch
This diploma thesis is focused on overall research of the quality of joining steel and aluminum alloy using the CMT welding process. The theoretical part describes the principle and the technology of the welding system that allows joining dissimilar materials by an electric arc. Attention is also given to other modes such as CMT Advanced, CMT Pulse and CMT Advanced Pulse, which further improve the innovative process. These modifications include an efficient tandem method CMT Twin that uses two electric arcs in various combinations. The main aim of the experiment is assessment of the quality of created CMT joints. Individual tests are conducted to evaluate the corrosion resistance in an aggressive environment (salt fog). The testing subsequently evaluates mechanical properties by a destructive tensile test to determine the tensile strength. Part of the quality assessment is metallographic analysis including determining the elemental composition of the weld.
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Preparation and properties of Bioglass based foam materials
Nedbalová, Radka ; Hadraba, Hynek (referee) ; Dlouhý, Ivo (advisor)
The work deals with the preparation and mechanical properties of coated Bioglass® 45S5 based foam materials with open porosity. The samples have been fabricated applying the replication method with use of polyurethane foam. Furthermore, these samples were coated in order to increase the strength characteristics and crack resistance. Polyvinylalcohol and PVA with cellulose microfibrils have been used as coating. Besides microstructural parameters of investigated materials using the SEM images strength characteristics in compression and in tension were also quantified.
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The verification of durability of surface layer by pull-off testing
Fujačková, Hedvika ; Komárková, Tereza (referee) ; Kocáb, Dalibor (advisor)
The theoretical part of this bachelor's thesis defines the basic properties, categorization, and use of the individual components of concrete and presents the properties of fresh and hardened concrete, especially the tensile strength. Furthermore, the thesis addresses the problem of durability assessment of concrete, which depends directly on the quality of the surface layer. The experimental part of the thesis focuses on executing of a pull-off test and examines the surface layer tensile strengths of various concrete mix designs. The thesis examines how the results of the measurements correspond with other published results.
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Properties of cement composites with fiber reinforcement
Jankech, Filip ; Sitek,, Libor (referee) ; Bodnárová, Lenka (advisor)
This thesis summarizes the knowledge of the possibility of using organic fibres as dispersed reinforcement into cement composites. It is concretely a summary of knowledge about the types and properties of synthetic and cellulosic fibres, their influence on the properties of fresh and hardened cement composite and lastly a description of the fire resistance of cement composites and the effect of organic fibres on the action of those composites at high temperatures and in the presence of fire. The experimental part is supposed to verify the effect of the cellulose fibres on increasing the durability of the cement composite at high temperatures.
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Pevnost lepeného spoje ve smyku materiálů na bázi dřeva v extrémních podmínkách
Hromádka, Petr
This thesis deals with the issue of adhesive joints under extreme conditions. The aim of this work is to determine influence of temperatures -30 °C, +23°C, +70 °C on maximal tensile strength of adhesive joint and to determine which adhesive has the best results when used on specific agglomerated materials. Manufactured samples (chipboard, chipboard press-veneered by spruce, fibreboard, beech plywood board) were used in process of solving the task. These samples were used in accordance with standard ČSN EN 205. Data were processed by software and evaluation was accomplished by using statistical methods. As a result of a detailed research the adhesives appropriate for use in extreme conditions on Earth were determined. Contribution of this work is clarification of the impact of exposure temperature, type of adhesive and interaction between temperature of exposure and type of adhesive. Based on obtained results appropriate type of adhesive for given temperature during maximal tensile stress can be recommended.
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