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Influence of a size of a cutting edge rounding of the insert during turning
Tichá, Dana ; Sedlák, Josef (referee) ; Dvořák, Jaromír (advisor)
The work is focused on the durability test of replaceable cutting inserts, which are coated with a newly developed coating. In the work are tested two types of replaceable inserts with different shapers, while three different edge roundings are produced for each shaper. The test is performed on three different materials. During testing, the cutting depth doesn’t change, only the feed changes, where tests are performed on each material at two different feeds. A different cutting speed was chosen for each material and feed, which resulted in a durability of the replaceable insert cca 15–20 minutes. The goal of the work is to find out what is the most suitable rounding of the blade on replaceable cutting inserts, when applying a newly developed coating.
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Effect of cutting inserts surface treatment on turning durability of stainless steel
Filip, Jiří ; Vítek, Jiří (referee) ; Sedlák, Josef (advisor)
The diploma thesis deals with the testing of coated carbide inserts with different types of surface treatments. The testing was conducted using longitudinal turning technology under constant cutting conditions, and the workpiece material used was austenitic corrosion-resistant steel. The aim was to analyze the wear progress of the cutting edges after predetermined time intervals and to determine the resulting durability of the tested inserts. During the testing, the cutting edges of the tools broke off and the required durability was not achieved. After a thorough examination of the workpiece material, a significant amount of unevenly distributed inclusions was found in the steel structure, which proved to be the main cause of the insert breakage. Therefore, it was decided to perform a replacement test using material from a new supplier. Material analysis of the newly delivered steel showed a significantly better purity of the structure, which was positively reflected in the results of the second test, in which there was no brittle fracture of the edge in any case and the tested samples reached the required durability. The best results were obtained with samples treated on flanks using a new surface treatment method developed by Dormer Pramet s.r.o. After completing the tests, an adhesion test of the coating to the tool substrate was performed using the Rockwell method. Based on microscopic images that revealed partial delamination of the coating, it was evaluated that the quality of the deposited layer was not quite optimal. In a technical and economical evaluation were determined the potentially saved costs when using the experimental cutting insert compared to the reference plate A.
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Possibilities of using recycled aggregates for the production of structural concrete
Hrachovcová, Ludmila ; Brožovský, Jiří (referee) ; Hubáček, Adam (advisor)
The bachelor thesis deals with the study of recycled aggregates and concretes made from them. Nowadays, more and more emphasis is being placed on recycling waste and especially construction and demolition waste. Therefore, we are looking for ways to use recycled aggregates in concrete composites despite heterogeneous parametres of concrete and brick recyclates. The paper summarizes the existing knowledge about recycled aggregates, especially about brick and concrete recyclates, their parameters and possibilities of their use. Furthermore, the thesis deals with brick and concrete recyclate concretes, their parameters and behaviour and their subsequent use in practice.
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Study of properties of concrete and brick recycled aggregate and its use for structures
Lípová, Sabina ; Voves, Jiří (referee) ; Hubáček, Adam (advisor)
This bachelor thesis studies the existing knowledge on recycled aggregates, particularly brick and concrete recyclates. It describes the properties and parameters of different types of recyclates and their possible applications in structures such as concrete, base courses, non-structural parts of pavements, etc. It also deals with the development of a methodology for selecting and testing recycled aggregates with the possibility of using them to meet the requirements of aggregate standards. Geometric, physical and mechanical parameters of aggregates that could affect the properties of the materials for structures made from them have been studied
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Methods of assessing the durability of concrete against frost and chemical deicing salts in the Czech Republic and in Europe
Žíla, František ; Novosad,, Petr (referee) ; Hubáček, Adam (advisor)
The bachelor thesis deals with the methods of assessing the durability of concretes against frost and chemical deicing salts used in the Czech Republic and Europe. The theoretical part of the thesis describes the basic properties of concrete, the classes of environmental influence, the theory of concrete failure by cyclic freezing and thawing, methods for assessing the durability of concrete against freezing and methods for assessing the durability against water and chemical deicing salts, as well as properties affecting the repeatability and reproducibility of tests. The practical part focuses on testing the resistance of concrete to the action of freezing and chemical thawing agents using the methods according to the standards ČSN 73 1322 and ČSN 73 1326 and also on the influence of concrete surface treatment on the process and result of these tests.
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Mobile shopping bag design
Leskovská, Monika ; Rubínová, Dana (referee) ; Rajlich, Jan (advisor)
The bachelor thesis deals with the design of a mobile shopping bag. The main objective is to design an innovative solution for the design of the mobile bag that will assist users of any age. As this is a product used mainly outdoors, it is necessary to pay attention not only to the shape solution but also to the aesthetic one. By striving to eliminate instability and with an emphasis on practicality, the product is tailored for everyday use in any environment to appeal to a wide range of users.
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Chování slaměných ekopanelů ve stavbách při dlouhodobému vystavení povětrnosti
Sion, Matěj
This bachelor's thesis deals with issues related to the resistance of straw eco panels. In the experiment, we will observe the influence of weather conditions (and the influence of the orientation of the sides of the world), causing changes in four test samples, where each eco panel is provided with a different surface treatment. 1. The first sample was taped with paper tape according to the recommendations of EKOPANELY SERVIS s.r.o.. 2. The second sample was provided with tape to the exterior 3. The third sample was provided with a layer of fiberboard mesh and adhesive mixture 4.The fourth sample was provided with a wood fiberboard, an adhesive mixture and subsequently a facade system. The samples prepared in this way were exposed to various weather conditions for one year. The final condition of the samples will be assessed on the basses of the fact whether and how they affect the future properties of the construction.
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Study of concrete properties in extreme climatic conditions
Stará, Tereza ; Novosad,, Petr (referee) ; Hubáček, Adam (advisor)
The bachelor thesis deals with the study of concretes that are exposed to extreme climatic conditions during their service life. Many concrete structures around the world are exposed to various climatic conditions during their service life, such as high temperatures or, conversely, low temperatures. These conditions affect the properties of concrete both in its fresh and hardened state and have an impact on its durability. This thesis summarises the existing knowledge of the behaviour of concrete in these conditions, and describes suitable input materials that can be used for these environments. Furthermore, the thesis describes the possibilities of improving the durability and resistance of concrete to these climatic conditions. In the experimental part, selected durability parameters of concrete are monitored during its exposure to climatic stresses.
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Testing of Vehicle Suspension Components
Šidla, František ; Blaťák, Ondřej (referee) ; Hejtmánek, Petr (advisor)
This bachelor thesis deals with issues related to testing car chassis components during development. Automobile transport is the most common type of long-distance transport. That's why vehicles are constantly evolving to provide the best possible performance. Increasing demands on consumers are being placed on vehicles because of the introduction of modern technologies. New technologies and concepts need to be thoroughly tested that they can be properly integrated into existing models. Test devices for determining the characteristics of the chassis are generally described here using specific examples of individual machines. Subsequently, the work clarifies the testing of the service life of individual parts of the chassis. The last part is devoted to the conceptual design of a simplified hydraulic device for testing coil springs. From the calculated characteristics, a hydraulic actuator and pump are selected from the relevant catalogues. In conclusion, the importance of car testing in development is summarized, individual types of testing are described and the readiness of test devices for the future is indicated.
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Study of FRP for concrete reinforcement
Blahová, Aneta ; Prokeš,, Jan (referee) ; Bodnárová, Lenka (advisor)
The diploma thesis aims to analyze bent FRP reinforcements. It describes the method of production of bent FRP reinforcement, examples of application of FRR reinforcement in structures and mentions aggressive influences influencing the durability of FRP reinforcement. Furthermore, an experiment is proposed to monitor changes in straight and bent FRP reinforcement stored in an aqueous environment at 20 °C and an alkaline environment at 20 °C and 40 °C. The output of the diploma thesis is the evaluation of changes in mechanical properties and durability. The condition of the FRP reinforcement is documented using optical and electron mocroscopy.
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