|
|
Pedestrian bridge across the lagoon
Bezručová, Kristína ; Kaláb,, Pavel (referee) ; Nečas, Radim (advisor)
The aim of this thesis is the design and analysis of pedestrian bridge across the lagoon. Three variants were designed. The variant of structure, which combines stress ribbon with steel arches, was chosen for analysis. There is a chapter in this thesis which deals with an ideal shape of arches for different types of loads. The calculation of load effects was made in software Ansys 17.0, considering scnstruction stages. Ultimate limit state and state limit state are evaluated. For evaluation of concrete cross sections was used MS Excel. Steel cross sections were evaluated in software Ansys 17.0. d Dynamic behaviour of construction was assessed. The mode shapes and natural frequencies were calculated. The harmonic excitation response was studied. The loss of stability was checked. The design and assessment are according to the european standards.
|
|
|
Nonlinear buckling analysis of a flue gas pipe
Jelínek, Jan ; Vincour, Dušan (referee) ; Létal, Tomáš (advisor)
This thesis deals with the nonlinear analysis of stability loss of flue gas pipe. This pipe is a part of desulphurization line. The thesis describes the creating of a simplified FEM model. It also describes the setting of the boundary conditions of the model for few loading cases. These cases differ by preference for one of the load as dominant. There are proposed several variants of stiffening by light ring stiffener. The work is finished by comparing the resistance to the stability loss of the reinforced variants and unreinforced model of flue gas pipe.
|
|
|
Linear buckling analysis of a flue gas pipe
Jančík, Jan ; Klučka, Ivan (referee) ; Naď, Martin (advisor)
The diploma thesis deals with the loss of stability of thin-walled flue pipe at coal power plant. The problem of thin-walled structures is their propensity to the loss of stability due to abnormal conditions, for example a vacuum, effect of wind, snow and earthquake. The purpose is to find the optimal deployment of reinforcements so that the model meets the requirements of EN 1993-1-6. This required an evaluation of unreinforced version of the model to identify weaknesses and subsequently other configurations for the application of reinforcement. For determining the resistance the flue pipe to the loss of stability used primarily to access linear bifurcation analysis based on linear analysis, possibly materially nonlinear analysis. The result of work is a design of reinforcement of pipeline which under the requirements of the standard meets the latest model with a reserve of approximately 20 %.
|
|
|
Modelling of Load Impacts Acting on Transport and Handling Equipments with the Aim of their Optimization
Šťastný, Antonín ; Hrabovský, Leopold (referee) ; Kuľka,, Jozef (referee) ; Škopán, Miroslav (advisor)
This PhD thesis deals with employment of the state of the art methods of mathematical optimization and structural analysis in the field of load carrying steel structures of handling devices. The goal of the thesis is to compile a methodology which enables generating of optimal dimensions of conceptually designed load carrying parts of handling devices. The proposed methodology is composed of sub-methods which are successively applied to find an optimal configuration of structure according to a chosen criterion. The methodology incorporates sub-methods such as Design of Experiments, parametric finite-element modelling, the state of the art computational methods for stability assessment, mathematical approximation methods and state of the art optimization schemes based of both, heuristic and gradient principle. Recommendations from Eurocode 3 are used to introduce imperfections to the finite element model in order to perform the nonlinear buckling analysis. The practical part of this thesis is focused on optimization of welded beams. The principle of the methodology is in detail explained and demonstrated on an example of lifting spreader beam of load carrying capacity of 20 tons. The proposed methodology is practically realized by an algorithm created in Matlab software. Matlab is also utilized to implement some sub-methods including mathematical optimization schemes. Both, gradient and heuristic optimization algorithms are used for comparison and mutual verification. Structural analysis is performed by means of parametrical finite-element models which are built in the Ansys Parametric Design Language (APDL). The methodology takes into account buckling, which is inherent to thin walled structures under compressive load. The buckling analysis is performed by means of both, linear and non-linear procedures in Ansys. The output of the algorithm is an optimized configuration of the structure, which minimizes the objective function and complies with all requirements implemented in the form of design constraints.
|
|
|
Analysis of transport aircraft damage during of terrorist attack
Čížková, Markéta ; Jetela, Václav (referee) ; Petrásek, Miloslav (advisor)
In its theoretical part, the diploma thesis deals with the reasons leading to terrorist attacks and a brief list of some attacks on aircraft. It also focuses on the aircraft as the target of a terrorist attack, especially the aircraft kite as the major researched part. The conclusion of the theoretical part summarizes a list of types of aircraft fuselage structures in respect of design solutions for load transfer. The practical part determines the extent of damage caused by a missile with a fragmentation warhead. This scope is then applied to the illustrative case. In the following chapters, the calculation of the critical force of a panel loaded with pressure depends on the different nature and extent of damage. Then the work highlights the evaluation of the obtained results, which are also summarized in the conclusions of the work.
|
|
|
Evaluation of geometry effect on structural panel stability with the use of Finite Element Methods
Klepiš, Daniel ; Augustin, Petr (referee) ; Katrňák, Tomáš (advisor)
This bachelor thesis deals with the problem of loss of stability of a reinforced wing panel. Within the research part of the thesis, an overview of the types of instabilities is created, thanks to which it is possible to verify the phenomena occurring in the whole area of progressive loading of the panel. The classical concept of longitudinal section reinforcement is enriched by an unusual type of so-called tree reinforcement inspired by the bionic structure of the leaf. For the panel modified in this way, two models are created in which selected dimensional parameters are changed. All the variations are numerically calculated using nonlinear analysis in MSC Patran/Nastran. For comparison of the calculated panels, a series of graphs are produced showing the force transfer and the percentage increase in the maximum force transfer with loss of stability. The selected variant of the parametric model is also compared in terms of mass increase. This allows a better verification of the appropriate panel for further detailed analysis.
|
|
|
Buckling of Plastic Specimens Manufactured by 3D Printing
Seidler, Lukáš ; Horák, Marek (referee) ; Löffelmann, František (advisor)
The bachelor’s thesis deals with the problematics of loss of stability in specimen created using the 3D printing technology. The beginning is devoted to a quick familiarization with the problems of 3D printing and a quick overview of the common faults present in the final products. For the purpose of testing the stability there were designed special testing specimens. Their theoretical values of critical force were than calculated using analytical and Finite Element approach. These values were than verified by testing the specimen inside a LabTest 6.500 machine and results were evaluated as per norm. The results clearly indicates that the theoretical force values are always bigger than the measured ones. Differences between these two are compared in multiple of graphs at the end of this thesis.
|
|
|
Analysis of transport aircraft damage during of terrorist attack
Čížková, Markéta ; Jetela, Václav (referee) ; Petrásek, Miloslav (advisor)
In its theoretical part, the diploma thesis deals with the reasons leading to terrorist attacks and a brief list of some attacks on aircraft. It also focuses on the aircraft as the target of a terrorist attack, especially the aircraft kite as the major researched part. The conclusion of the theoretical part summarizes a list of types of aircraft fuselage structures in respect of design solutions for load transfer. The practical part determines the extent of damage caused by a missile with a fragmentation warhead. This scope is then applied to the illustrative case. In the following chapters, the calculation of the critical force of a panel loaded with pressure depends on the different nature and extent of damage. Then the work highlights the evaluation of the obtained results, which are also summarized in the conclusions of the work.
|
|
|
Pedestrian bridge across the lagoon
Bezručová, Kristína ; Kaláb,, Pavel (referee) ; Nečas, Radim (advisor)
The aim of this thesis is the design and analysis of pedestrian bridge across the lagoon. Three variants were designed. The variant of structure, which combines stress ribbon with steel arches, was chosen for analysis. There is a chapter in this thesis which deals with an ideal shape of arches for different types of loads. The calculation of load effects was made in software Ansys 17.0, considering scnstruction stages. Ultimate limit state and state limit state are evaluated. For evaluation of concrete cross sections was used MS Excel. Steel cross sections were evaluated in software Ansys 17.0. d Dynamic behaviour of construction was assessed. The mode shapes and natural frequencies were calculated. The harmonic excitation response was studied. The loss of stability was checked. The design and assessment are according to the european standards.
|
|
|
Nonlinear buckling analysis of a flue gas pipe
Jelínek, Jan ; Vincour, Dušan (referee) ; Létal, Tomáš (advisor)
This thesis deals with the nonlinear analysis of stability loss of flue gas pipe. This pipe is a part of desulphurization line. The thesis describes the creating of a simplified FEM model. It also describes the setting of the boundary conditions of the model for few loading cases. These cases differ by preference for one of the load as dominant. There are proposed several variants of stiffening by light ring stiffener. The work is finished by comparing the resistance to the stability loss of the reinforced variants and unreinforced model of flue gas pipe.
|
guest ::
