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Comparison of reliability methods in determining the design resistance of a bridge
Šplíchal, Bohumil ; Doležel, Jiří (referee) ; Lehký, David (advisor)
This thesis deals with the topic of assessing the design load-bearing capacity of a prestressed concrete railway bridge structure. The determination of the structure’s load-bearing capacity is carried out using probabilistic nonlinear analysis using the finite element method. Load-bearing capacity is determined for the recommended limit states. A fully probabilistic approach is compared to other reliability semi-probabilistic methods, such as the ECoV method according to Červenka and Eigen ECoV, and deterministic methods, like partial safety factor method, or the method according to ČSN EN 1992-2. The results are evaluated in terms of accuracy, consistency and time consumption for each method.
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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.
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Design of concrete elements with FRP reinforcement
Mrkvová, Kateřina ; Lagiň, Juraj (referee) ; Kostiha, Vojtěch (advisor)
This diploma thesis focuses on deflection of reinforced concrete structures with FRP rebar. The thesis presents and compares various approaches on deflection of reinforced concrete structures with steel and FRP rebar based on national and international standards and existing research. The aim of the thesis is to point out differences among the various approaches and present the most suitable one for the particular case. Based on theoretical and experimental results, the goal is to modify one of the existing approaches or present a new method which would correspond with real deflection behaviour of FRP reinforced concrete beam. Simply supported beam with three-point bending was selected as a reference element. Analytical study and numerical analyses by ATENA software are performed. Results of analytical and numerical study are compared to experimental results.
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Design of selected details of concrete structures reinforced with composite reinforcement
Vašátko, David ; Lyčka, Lukáš (referee) ; Girgle, František (advisor)
The aim of this master thesis is to explore and describe behavior of slab in punching shear. In total four concrete slabs were experimentally tested; each being reinforced differently. Using real experiments, there was a possibility to observe different behavior of steel and FRP reinforcement, eventually even the effect of adding FRP stirrups on load-bearing capacity. For the purpose of experimental testing design, currently placed formulas used to determine punching shear capacity were adjusted for application on longitudinal and shear FRP reinforcement. Atena software was used to approximate behavior of specimens by performing a nonlinear analysis. After the results of loading tests were obtained, next step was the comparison of design approaches and comparison of behavior of nonlinear model to a real specimen. In practical part, design of locally supported slab with requirement of non-magnetic reinforcement took place.
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Comparison of reliability methods in determining the design resistance of a bridge
Šplíchal, Bohumil ; Doležel, Jiří (referee) ; Lehký, David (advisor)
This thesis deals with the topic of assessing the design load-bearing capacity of a prestressed concrete railway bridge structure. The determination of the structure’s load-bearing capacity is carried out using probabilistic nonlinear analysis using the finite element method. Load-bearing capacity is determined for the recommended limit states. A fully probabilistic approach is compared to other reliability semi-probabilistic methods, such as the ECoV method according to Červenka and Eigen ECoV, and deterministic methods, like partial safety factor method, or the method according to ČSN EN 1992-2. The results are evaluated in terms of accuracy, consistency and time consumption for each method.
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Nonlinear analysis of continuous welded rail in curves of small radius
Murínová, Klára ; Szabó, Petr (referee) ; Plášek, Otto (advisor)
The diploma thesis examines the influence of curve radius on continuous welded rail stability in a small radius curve. Attention is paid to curves with a radius less than 300 m. The first part of the thesis summarises the theory of continuous welded track and influence of track parameters on track stability. The second part of the thesis deals with constructing of the numerical model of a curved track with the observed behaviour of track under thermal loading with positive and negative temperature values. The variable values in the model are rail shapes and different radius. In the end, the shape of the track lateral deflection as a function of temperature are evaluated.
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Design of concrete structures reinforced with non-metallic FRP reinforcement
Golisová, Michaela ; Januš, Ondřej (referee) ; Kostiha, Vojtěch (advisor)
This diploma thesis investigates the design of concrete structures reinforced with non-metallic FRP reinforcement with a focus on solving the bearing capacity in extrusion. The work is divided into a theoretical and a practical part. The theoretical part begins with an introduction to FRP reinforcement and a description of shear stress. The following is an introduction to current approaches dealing with this issue. In the practical part, in connection with these regulations, parametric studies are developed to compare the influence of individual input parameters and selected regulations. The last part is dedicated to the design and nonlinear analysis performed in the ATENA software.
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Determination of design resistance of reinforced concrete bridge
Šplíchal, Bohumil ; Doležel, Jiří (referee) ; Lehký, David (advisor)
This thesis deals with the topic of assessing the design load-bearing capacity of a reinforced concrete bridge structure. The determination of the load-bearing capacity of the structure is carried out by means of probabilistic nonlinear analysis using finite element method. Load-bearing capacity is determined for the recommended limit states. A fully probabilistic approach is compared to other recommended reliability methods, such as the ECoV method according to fib Model Code 2010, the partial safety factor method, or the method according to ČSN EN 1992–2. The results are evaluated in terms of accuracy and time-consuming for each method.
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Reconstruction of the cable suspended footbridge in Kroměříž
Liška, Jaroslav ; Kulhavý,, Tomáš (referee) ; Klusáček, Ladislav (advisor)
The Diploma thesis deals with the reconstruction design of a footbridge in the city of Kroměříž, Czech Republic. The footbridge would serve as safe transport for pedestrians over the Morava river. The main objective of the thesis is to conceive two or three reconstruction designs. The most suitable one will be opted for and elaborated in more detail. Eventually, strengthening of the bridge by means of additional prestressing using mono-strand post-tensioning systems is picked as the best solution of the planned reconstruction. The monostrand post-tensioning system is led under the deck, the cross section being outside. External cables are anchored in concrete blocks built around existing supports. Load-generated internal forces are calculated on a spatial bar model with non-linear first-order analysis. The calculation is executed using the finite element method in the midas Civil programme. The chosen reconstruction design is then assessed against load capacity limit states, and functionality. Also, the designed reconstruction is assed for dynamic effects. Results are compared with existing structure, and verified against the real-time tensometric measurement-obtained data. Dimensions, assessment of load-bearing structure, and structural details are all made according to valid Eurocodes.
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