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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Výpočtové modelování hluku v kabině letounu VUT 100 Cobra / Computational modelling of noise inside cabin of aircraft VUT 100 Cobra

Prnka, Jiří January 2010 (has links)
This master’s thesis deals with the computational simulation of low-frequency noise inside the cabin of small commercial airplane VUT 100 Cobra. For this low-frequncy range deterministic methods: Final Element Method (FEM) and Boundary Element Method (BEM) are used for simulation of the dynamic behaviour of the object. FEM has been used to compute eigenmodes and eigenfrequences of the structure of the aeroplane cabin and of the acoustic space inside cabin. Then response to harmonic excitation of engine represented by unit forces in place of contact has been computed. Obtained velocities on the surface of the cabin are then used as the basis for the noise calculation inside the cabin using BEM. After that effect of some construction modifications on sound level inside cabin are evaluated by computational modelling.
72

Vývoj modelů chování Al slitin pro aplikace v numerických simulacích svařování a tepelného zpracování / Development of Models of Al Alloys Behaviour for Applications in Numerical Simulations of Welding and Heat Treatment

Vaněk, Mojmír Unknown Date (has links)
The thesis deals with methodology for computational approaches for numerical simulations of welding and heat treatment of aluminium alloys. The thesis describes improvement of the current methodology for metallurgical part of the numerical analysis of welding, which is important mainly for prediction of dimensions of the heat affected zone (and deformations). The improvement was carried out based on CHD diagram that describes precipitation and dissolution of phases during continuous heating. The thesis also describes carried material measurements (measurement of chemical composition, dilatometric tests, tensile tests of several conditions of materials at temperatures up to 500 °C and measurement of aging curves), which allowed to significantly refine analysis results for the alloys EN AW-5083 and EN AW-6082. Based on an evaluation of the measurements, several conclusions were made. They can be useful for creation of material databases of other aluminium alloys. The thesis also describes quantification of dependence between tensile strength and yield strength on the Vickers hardness for different conditions of EN AW-6082. There is also methodology for numerical simulation of the heat treatment process of heat treatable Al alloys in the dissertation. The methodology is completely new approach which has never been published so far. Application of this method is based on user changes of the material database in software Sysweld after relatively easy measurement of aging curves. Therefore, the methodology can be considered as promising for application in industrial practice.
73

Počítačová hra ve výuce chemie na SŠ / Computer game in the education at secondary school

MATOUŠEK, Michal January 2015 (has links)
This thesis is focused on usage of computer game (adventure game) in teaching of chemistry. Game is situated to the town of Český Krumlov and contains set of tests from nomenclature (names and symbols of chemical elements). This game can be used to motivate students to study chemistry on lower grades of grammar schools and higher grades of elementary schools.
74

Sdružené transportní procesy / Coupled transport processes

Jeřábek, Jakub January 2015 (has links)
The objective of this thesis was to implement a new module to the DRUtES model code, which allows to calculate coupled transport of moisture, temperature and miscible substance in a variably saturated porous media. The main part of the practical phase of the thesis was to implement appropriate constitutive relationships describing a coupled transport to the Galerkin finite elements scheme previously implemented in the DRUtES model. Besides this, a corresponding configuration files were made to assign parameters of the model into program data structures as well as a little bit of other programming work elsewhere in the code. Numerical solution of each transport equation was compared with its analytical solution. 1D moisture transport with the Philips semi-analytic solution of diffusive form of Richards equation. 2D temperature and miscible substance transport with an analytical solution of advection-dispersion equation. This comparisons suggested that the implementation was correct. The coupling of these processes was compared with a reference numerical solution. In this case was the fitness of results assessed in more qualitative manner with a literature. Before use of this coupled model to solve a real world problem, I would recommend to make a similar assessment with the real data.
75

Kinematika a elastokinematika nezávislého víceprvkového zavěšení nápravy se zohledněním poddajnosti nosných prvků / Kinematics and elastokinematics of independent multi-link suspension of axle using flexible supporting elements

Vrána, Tomáš January 2016 (has links)
This thesis deals with elasto-kinematic properties of multi-link rear suspension system, based on simulations. The creation of computational model and simulation of elastokinematics are based on specialized modules of the HyperWorks software. The thesis idea is to create new models and improve their properties. The chapter introduction presents and discusses the current knowledge state in the issue of elasto-kinematic characteristics of the vehicle suspension. Previously published works are presented in this section. The following section defines basic terms, features and design elements concerning the topic vehicle suspension and vehicle axle, which can help readers to orientate in this field. The first part of the thesis is focused on the collection of high-quality input data to create the MBS computational model based on the real suspension components. The determination of kinematic suspension points, experimental measurements of inertia moments of supporting elements of the suspension and measurements of deformation characteristics of rubber-metal bushings are presented in the thesis. There are also measuring characteristics of force elements such as springs or shock absorbers. Then the proposed method of measuring elasto-kinematic characteristics of the suspension using testing machine for model validation is also introduced. The second and main part is devoted to creating a new MBS simulation models of multi-link rear suspension using HyperWorks system. The suspension model is improved by successive steps, from kinematic model, through model with flexibility of the bushings, to the complex model in which the flexible properties of all supporting elements are reflected. The properties of the used models are described together with arising calculation problems. The results discuss the impact of elements flexibility and individual structural alternatives on elasto-kinematic characteristics of the suspension system.
76

Optimalizace parametrů úlohy s rázovým zatížením v programu LS-DYNA

ŠTANGL, Jiří January 2016 (has links)
Master's thesis focuses on numerical modeling of automotive tasks. The text is divided into two main parts. A fuel supply module is the main topic of all numeric analyses of this thesis and it is introduced in the first part. Basics of theoretical continuum mechanics and finite elements method are also explained in the first part. The second part is split into two main topics of the fuel supply module - material damping and contact numerical modeling. Practical reasons for parameter optimization are explained along with particular optimization results and underlying theoretical background.
77

Nastavitelný rozchod kol zadní nápravy traktoru / Adjustable Track of Tractor Rear Axle

Šíbl, Michal January 2013 (has links)
This Master´s thesis deals with construction design adjustable track of tractor rear axle in a company Zetor Tractors a.s. At the very beginning there is an overview of different possibilities adjustable track from other world´s producers of tractors. Afterwards there is my constructional working from selection variant of suspension to final project. In this case the thesis contains required calculations of the whole device. Thesis also contains the stress and strain analysis of significant part of construction using a numerical approach of finite element method (FEM) and drawing documentation of the project constructed device.
78

Velkoobjemová nástavba pro nosič výměnných nástaveb pro agrotahač 6 x 6 / Large volume carrier body for swap bodies for agri truck 6 x 6

Tůma, Martin January 2015 (has links)
This diploma thesis deals with proposal large volume carrier body for swap bodies with volume 60 m3. In beginning the thesis includes background research part. In the middle part describes the design of conception body. Work in the last part contains the strength calculations using the finite element method. Strength checks consider especially deformation and strain analysis in different load angle states. Part of the thesis is also design documentation. Work is created in co-operation with company ZDT Ltd.
79

Podvozek jednoúčelového vozu MEGA EASY / Chassis of single purpose trailer MEGA EASY

Nouza, Pavel January 2014 (has links)
This diploma thesis deals with conceptual design chassis of tractor trailer with maximum weight 21 000 kg. First part of thesis introduces reader with division of constructal chassis elements. Next part deals with conceptual chassis design. The final part deals with strenght control of chassis frame, which has been designed in previous chapter. In last part of the thesis deals with stress control designed construction of the frame. Drawing documentation of chassis frame is a part of the thesis
80

Zvedák dopravníku s paletou / Hoist with a pallet conveyor

Hluzín, Filip January 2017 (has links)
This diploma thesis deals with the design of the conveyor lifter with a pallet according to specified parameters. The thesis includes functional, dimensional and strength calculations, control of the most stressed part using finite element method. Part of the thesis is also an assessment of the maintenance and operation requirements of the machine. The thesis is accompanied by drawing documentation of selected assemblies.

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