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Geodetic monitoring of the tubosider in Liberec under the ski slope F10
Buchar, Ondřej ; Jarůšek, Ladislav (referee) ; Kratochvíl, Richard (advisor)
This thesis describes a geodetic monitoring of a deformed steel structure tubosider in Liberec. There have been made periodic measurements of displacements and deformations of the object since 2015. Various interventions have been made in order to ensure a stability of the tunnel, which are also evaluated in this thesis. The results are graphs that describes shifts of the highest points in the tunnel. These values are further used by structural engineers and architects to suggest a solution.
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Analytical model of composite cantilever with SMART layer
Dostal, Vojtěch ; Ševeček, Oldřich (referee) ; Majer, Zdeněk (advisor)
This bachelor's thesis deals with analytical modelling of composite cantilever with smart layer. The structure is based on the real piezoelectric generator, which is a solid cantilever beam with a layer of piezoelectric material attached to its bottom and top. The first part of this bachelor's thesis summarizes the knowledge of the energy harvesting, the process under which harvesting of electric energy from the piezoelectric generator belongs. Some piezoelectric materials are mentioned and described afterwards. At first, analytical modelling is implemented on the homogeneous cantilever beam. Then, the relations for required characteristics are derived for laminate structure, which is structurally similar to the piezoelectric generator. One chosen parameter will be changeable. Due to the ties of relations, the required characteristics will change as well, which are for the piezoelectric generator strain and deflection.
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THE UNCERTAINTIES DEFORMATION AND STRESS USING THE STRAIN GAUGES
Dokoupil, Pavel ; Vlk, Miloš (referee) ; Koška, Petr (referee) ; Habán, Vladimír (advisor)
The dissertation thesis deals with the determination of uncertainty of strain measurement and the stress using resistance strain gages. You can find two methods to define the uncertainty in the thesis, GUF and MMC, and both are applied for measurements carried out with resistance strain gages. Definition of the measurement uncertainty was set for the strain measured by uniaxial and biaxial strain gages. The uncertainty of the stress was defined for linear strain gages, T Rosettes and Rosettes. There were universal mathematic-technical models defined to measure strain and stress, these models can be used either for standard and special measurements i.e. high-temperature, or for measurements in radiation field. Each part of the strain uncertainty and stress is analyzed from the point of view of a size of uncertainty and a form of probability of the function that strain and stress can adopt. The maximum focus was dedicated to the mistakes influencing measured strain like strain gage properties, installation and operating influences, external influences, time effects and the influence of the measured object. There are two mistakes influencing the stress described and analyzed in the thesis, the mistake of the Young’s modulus of elasticity and the mistake of the Poisson’s ratio. The thesis is conceived as a complex of information related to the measurement uncertainties using the resistance strain gages and methods of defining the measurement uncertainty in a way that the experimenter can apply the gained info and methods in the required measurements. The final chapters give representative examples to define measurement uncertainties for uniaxial and biaxial stress applying GUF and MMC method. The thesis also includes the experiment that compares measured values of strain, stress and measurement uncertainties, using several different types of strain gages at different temperatures, with theoretical calculation of strain and with stress. The experiment was carried out using the displacement sensor that works on an elementary principle of bending load.
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Determination of pressure in the pipe using foil strain gauge
Beran, Vojtěch ; Dokoupil, Pavel (referee) ; Habán, Vladimír (advisor)
This master´s thesis deals with determination of pressure in the pipe using foil strain gauge. It is calculation of the pressure from the measured strain. The main purpose of this work is devise mathematical-technological models to determinate internal pipe pressure from longitudinal deformation. Devised models were used on data from realized experiment and results were compared with real value of pressures in pipes. This thesis contains three models which were mutually compared. Sensitivity analysis were done on two of these models. Thesis also contains opening research of strain gauge problematics. Description of basic knowledge of physical objects mechanic with focusing on shells also belongs to this theoretical part.
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Development of concrete with limited volume changes
Martanová, Jana ; Skopal, Ing Karel (referee) ; Hela, Rudolf (advisor)
The bachelor thesis deals with volume changes of concrete. Attention is paid to the shrinkage. They describe the different kinds of volume changes in cement concrete, the reason for their creation and the ways in which they can be eliminated. The practical part is focused on monitoring the volume changes of concrete for 28 days using different amount of plasticing additives.
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Detail analysis of complex connection in the structure
Hokeš, Filip ; Hradil,, Petr (referee) ; Kala, Jiří (advisor)
The main objective of the thesis is to find and describe dependence between load carying capacity of a pin connection and a pin hole drilling. The dependence will be made in according to standard ČSN EN 1993-1-8, by theoretical solution and finally by finite element method in the ANSYS system. The second objective of the thesis is focused on a verification of load test results by numerical methods. Numerical solution will be made up in two analysis with different types of finite elements. The most fiiting model will be used as a basis for description of the relationship between capacity and diameter of drilling.
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Measurements of the stress in the turbine spiral casing using the strain gauges
Dokoupil, Pavel ; Pochylý, František (referee) ; Habán, Vladimír (advisor)
The Master‘s thesis is focused on measuring of the stress in the spiral case of water turbine using the strain gauges measurement. It contains the theoretical and the practical part. The theoretical part includes a description of theoretical background (basic mechanics, measurement and evaluation, strain gauges, pressure measurement, uncertainty of measurement). One of the chapters describes Water Power Plant Lipno nad Vltavou (history of power plant, issues and the history of measurement). The practical part contains a theoretical calculation of measurement uncertainty and measuring of stress on spiral case Francis turbine at Water Power Plant Lipno I (Unit TG2). Measurement was made before and after overhaul. There are described technical data of spiral cases, description of measurement, results of measuring of strain and stress including comparison with the pressure in spiral case and calculation of uncertainties of measurement.
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Determination of masonry modulus of elasticity in the direction of bed joints
Kuchař, Martin ; Klusáček, Ladislav (referee) ; Terzijski, Ivailo (advisor)
The determination of strain properties of masonry in the direction parallel to bed joints is a fundamental pre-requisite for designing structures, where masonry is subjected to horizontal stresses (e. g. strengthening with prestressing). The diploma thesis summarized techniques of determination of masonry modulus of elasticity presented in available literature. The goal is to suggest suitable methodology of determination of masonry modulus in direction parallel to the bed joints. In the practical part of the diploma thesis is that methodology verified by experimental test and results of tests are analyzed and discussed.
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The research of cause of failure of concrete elements Face Block
Eger, Lukáš ; Husařík, Petr (referee) ; Dufka, Amos (advisor)
This master thesis focus on the analysis of effects that cause defects in concrete blocks. Experiences show that the defect of the blocks are often manifested in the form of cracks. Great rate of occurrence of defects is attributed to volume changes of poor quality concrete filler. The aim of this master thesis is to analyze the finding from the practical use and exploration of the requirements for the actual blocks and especially the concrete filler which is used to make monolithic structures built from these blocks. The attention will be paid to the interaction between the block and the concrete filler. Here we focus mainly on the volume changes caused by a change of moisture level and especially the cyclic moisture.
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