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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.
1

Technologie odjehlování svařovaných trubek / On the technology of tube scarfing

Řezáč, Matěj January 2016 (has links)
The thesis is focused on the technology of scarfing longitudinal welds in welded tubes. The theoretical part describes methods of production tubes. It also analyzes the method used in Mubea company. The experimental part presents the design of two innovative technologies of scarfing welds tubes, their experimental validation and subsequent evaluation. The experimental part also presents a design of the machine that must be produced for this operation.
2

Návrh technologie výroby ohýbané součásti a konstrukční řešení nástroje / Project technology of production hooped components and structural design tools

Zachoval, Jan January 2009 (has links)
This diploma thesis has been elaborated within the Master's study of department 2307 that submits a production hooped component. The material of the component is steel ČSN 15 130. Single – part as far as small–lot production. On the basis of the literary study problems bend tubing was sugested the method: rotary draw bending. For this method was sugested mechanical bending machine with mandrel support arm, for bending with mandrel and exact bends in three – dimensional.
3

Analýza procesu ohybu trubky / Analysis of Tube Bending Process

Šrom, Jan January 2017 (has links)
Master thesis analyzes rotary draw bending of the tubes without using a mandrel. Bending process is accompanied by many defects due to large displacement of formed material. One of the major defects is flattering of the cross section also called ovality. In order to decrease ovality comes up a proposal of the changes to the tool design. Modifications of tool’s geometry are numerically analyzed by finite element method in software ANSYS. According to the results of the simulations an optimized pressure die is manufactured. Several experimental tests are accomplished to verify the effect of the optimized tool design. Approximately 100 bends confirm a decrease of ovality using modified pressure die.
4

Návrh výměníků tepla pro vysokoteplotní aplikace / Design of heat exchangers for high temperature applications

Jonák, Martin January 2010 (has links)
This thesis is devoted to thermal-hydraulic design and rating of heat exchangers with the specialized commercial software HTRI. These heat exchangers are solved for real high-temperature applications, where the hot fluid is a flue gas with high temperature (above 500 °C). In the thesis is made a brief analysis of the conventional design of heat exchangers usable for high-temperature aplications, description of the basic relations, description and brief user manual of software HTRI. Further, work includes a comparative study of methods for calculation of pressure drop of the fluid at 180° elbows, as support analysis for solution of required applications characterized by low pressure drop of process fluids.
5

Analýza potíží výměníku tepla / Analysis of heat exchanger troubles

Bartošek, Nikola January 2015 (has links)
The master thesis is focused on analysis of specific cross-flow in-line tube bundle heat exchanger which deals with significant operational problems. Thermal, hydraulic and vibration calculation analysis of selected parts of the heat exchanger is performed based on CFD flow distribution results. Calculation is performed by using Maple software. Thermal and hydraulic calculations are compared with results obtained by commercial software HTRI.
6

Numerická simulace rozšiřování trubky za dynamických podmínek / Numerical simulation of a tube flaring under dynamic conditions

Hlavačka, Daniel January 2017 (has links)
The thesis builds on the project FSI-S-14-2394, in which the biaxial state of tension of longitudinally welded tubes made from material 17 240 was investigated. The experiment was carried out under dynamic conditions on an impact tester, which was designed with structural simplicity and ease of observation of the experiment in mind. Deformation was recorded by high-speed cameras and a dynamometer. Results of the experiment were processed by measuring devices and subsequently used in a simulation created using a software utilizing the finite element method. Simulations were created for samples DA8 and DB9. These samples were selected because they did not crack and were fully stamped. Results of the simulation correspond to the values measured by high-speed cameras and a dynamometer with a small variance. Based on comparison of the results, it can be states that the simulation is technically acceptable.
7

Kriteria vzniku defektů při ohybu profilových trubek / Conditions of failures generation when bending profiled tubes

Fišar, Luboš January 2011 (has links)
The thesis describes the knowledge from a round tube bending technology, as a description of conventional and unconventional devices. There are technological parameters in relation to the creation of defects, and equations for determining the bending moment. These knowledge has been generalized and applied to solution the changes of cross-section shape and thickness in the bending of square cross-section. The solution was implemented to specific component (20x2 mm steel tube with two successive radii R57,2 and R131,5). The results of experiments shows that the material is almost rigid-perfectly plastic, in the most stressed areas has a sufficient supply of material formability. Thickness measurement was applied to calculate the approximate center of gravity changes. This shows a shift of 1.4 mm, which is negligible value for the pure bending. The end of the thesis summarizes the deficiencies of current manufacturing technology, which used mandrel is inadequate, wrong located and poor lubrication.
8

Distribuce toku v zařízeních s hustými svazky trubek / Flow Distribution in Equipment with Dense Tube Bundles

Babička Fialová, Dominika January 2017 (has links)
Significant maldistribution negatively influences performance of equipment containing dense tube bundles and, moreover, it can cause a wide range of operating issues. This thesis therefore focuses on analysis of fluid flow in complete distribution systems via computational fluid dynamics (CFD). Data obtained from simulations carried out using the software ANSYS Fluent were also statistically analysed. Influence of system arrangement, tube bundle parameters and operating parameters on flow distribution non-uniformity and pressure drop was investigated. According to the results, system arrangement is the crucial differentiating parameter in terms of flow distribution as well as pressure drop. Additionally, data obtained via the classical CFD approach were compared with those yielded by a simplified CFD model for three selected distribution systems. Simplified CFD approach can - given its low computational demand - be utilised in optimization algorithms as well as in the course of the initial stage of equipment design process. Furthermore, this thesis discusses a simulation tool which is based on the simplified CFD approach. Although this tool is still being developed, the results it yields are very promising.
9

Vliv výrobních parametrů na plasticitu konstrukční oceli / The effect of production parameters on the plasticity of structural steel

Brabec, Martin January 2020 (has links)
The master thesis deals with the influence of heat treatment and storage time on microstructure and mechanical properties of 26MnB5 steel, which is used in the production of tubular components in the quenched and tempered state. The objective was to increase the plasticity of the steel by the definition of new process parameters of the induction heat treatment line. New tempering diagrams of 26MnB5 steel for two various speeds of the heat treatment line were established and used to determine new tempering temperature and speed of the heat treatment line. Observation of the influence of storage time on mechanical properties of the steel did not reveal that it is liable to ageing.
10

Návrh automatického lisu / Design of automatic press

Ujčík, Miroslav January 2021 (has links)
The master's thesis deals with the design of a press, which will be part of a robotic workplace. This workplace is designed for a company operating as a subcontractor for the automotive industry, for which automation is one of the most important processes of development and increasing labor productivity. The robotized cell is part of a line for heat treatment of plastic tube semi-finished products. The cell itself is used to press the conical extension of the pipe ends using a steel mandrel. In order to manipulate the parts, the corresponding end effectors of robots are designed in the work, which safely load and remove parts from the automated press. Design and control calculations are supplemented by finite element strength analysis in Solidworks. A drawing documentation is also made in this program. The work is performed with regard to the requirements of technologists and the quality department.

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