|
|
Stress - strain analysis and creep assessment of the thick-walled tubular structures.
Zouhar, Michal ; Petruška, Jindřich (referee) ; Hlavoň, Pavel (advisor)
This thesis deals with the stress-strain analysis of thick-walled pipe parts. The dimension series (characterized by the D/d ratio) of three components are solved, then a direct tube, a torus with constant wall thickness (arcus) and a torus with variable wall thickness (bend). At first, the internal pressure amount, when a fully plastic state for these components is created, is solved. The amount of the limit pressure is determined analytically, numerically and by appropriate normative relations. The results and stress diagrams of individual solutions are mutually compared. Furthermore, these components are solved in the creep and are exposed to the maximum allowable normative internal pressure for 200,000 hours according to the standard – the operating time of components. The place of the maximum equivalent creep strain and the place of the maximum equivalent stress is examined. In these places the principal stresses are depicted depending on the D/d ratio. The results and stress diagrams of individual dimension series are mutually compared. From the available literary sources the condition of the limit state reach is chosen, according to which the evaluation of the limit state reach for individual components is carried out.
|
|
|
Computational models of shock absorbers of plastic and hyperelastic materials
Burdík, Martin ; Vlach, Radek (referee) ; Burša, Jiří (advisor)
An aim of the given thesis is creating of a computational model of strain-stress behaviour of shock absorbers made of plastic and hyperelastic material. First step is get ecquaint with theory of large strains, theory of hyperelasticity and plasticity. Next step is get ecquaint with options of commercial programs based on MKP. Based on this knowledge, models of simple shock absorber are made. With created models, crash tests are simulated and property of shock absorbers are compared.
|
|
|
Static analysis of one joint of timber structure
Sedlák, Petr ; Gratza, Roman (referee) ; Kytýr, Jiří (advisor)
This diploma thesis deals with the numerical modeling of the nail joint of the timber roof structure and it is based on the already realized physical experiment. Totally twelve various solutions, where the isotropic and ortotropic characteristics of the spruce timber and steel components change, have been created. The final values of the joint shift obtained by using of the numerical modeling are compared with results of physical experiment. Program system ANSYS is used.
|
|
|
Optimization of parameters of dynamic relaxation in solving plastic limit states of structures
Poláček, Milan ; Nevařil, Aleš (referee) ; Vlk, Zbyněk (advisor)
The aim of the thesis is to create an analytical model of frame construction. Determining load at which individual plastic hinges are formed until the collapse of the structure. The analysis is going to be performed by RFEM with an additional module RFDYNAM. Subsequently, the parameters of dynamic relaxation is going to be optimized to specify and speed up the calculations. Finally, the optimized parameters is going to be used to analyze the storeyed frame construction formed Ing. Jan Vales including a comparison of findings.
|
|
|
Study of impact of a transport vehicle into a structure.
Sychrová, Šárka ; Salajka, Vlastislav (referee) ; Němec, Ivan (advisor)
Master's thesis deals with the analysis of the impact of transport vehicle on a building structure. Transport vehicle is represented by an airliner and building structure is represented by a containment of a nuclear power plant. The aim of thesis was to explore the possibility of numerical simulation of an impact of transport vehicle on a building structure utilizing the RFEM program and evaluation of the damage extent.
|
|
|
Analysis of plastic bearability of plates
Rozsypalová, Veronika ; Hradil, Petr (referee) ; Němec, Ivan (advisor)
The subject of this thesis is analysis of the plastic bearability of plates. The first part is dedicated to a description of pertinent theories. It is primarily a theory of material nonlinearity and plasticity, including a description of plasticity models, which are commonly used in engineering analysis. Next is the hinted theory of geometric nonlinearity and discusses the key principles of limit plastic bearability of plates. This thesis includes ultimate strength calculations of plates of selected shapes, their solution by both, a manual calculation and using computational software. The obtained values are subsequently evaluated. The appendices contain the procedures for modelling in the computational programs RFEM and ANSYS.
|
|
| |
|
|
Computer simulation of building collapse due to formation of plastic hinges
Valeš, Jan ; Kala,, Zdeněk (referee) ; Vlk, Zbyněk (advisor)
The aim of the thesis is to create an analytical 2D model of a multi-storey building and its consequent loading until the point of collapse which occures due to formation of plastic hinges. The first part is going to present a linear analysis of the problem; it focuses on location and level of load when the plastic hinges are formed. Then a nonlinaer analysis is going to be performed by RFEM programme using postcritical analysis and dynamic relaxation. Differences between the results of mentioned types and methods of analysis are going to be compared and an impact of variables is going to be evaluated .
|
|
| |
|
|
Methylene Blue Test for Plasticity Determination of Brick Clays
Jiroušek, Štěpán ; Stančík,, Hynek (referee) ; Sokolář, Radomír (advisor)
The Bachelor thesis is focused on methods for assesing the plasticity of ceramic raw materials (clays). The theoretical part describes the origin, species, chemical and mineralogical composition of these raw materials. Then we describe the preparations and standardized and nonstandardized methods of assesing the plasticity of clay used in the Czech Republic and abroad. The practical part describes executed tests of brick soils specimen used in the Czech Republic. The outcome of this work is to find correlations between these tests and the determined value of sorption of methylen blue.
|
guest ::
