|
|
Analysis of a plan curved cable stayed and suspension footbridges
Koláček, Jan ; Stráský, Jiří (advisor)
The aim of the doctoral thesis focuses on the static and dynamic analysis of a plan curved cable stayed and suspension pedestrian bridges suspended on a single-side of their deck. The first part of this thesis deals with an analysis of the equilibrium in the transversal direction of a deck cross section suspended on a single-side. The section and its arrangement should be designed so that the torsion caused by the deck self-weight and dead load would be minimal. This theory was verified on a simple study of a single-sided suspended section with and without prestressing. Second part of the thesis deals with the design of a study of a plan curved cable stayed pedestrian bridge. The study describes in detail a finding of an initial state of the structure and the static and dynamic analysis performed by software ANSYS. The static analysis describes the response of the structure on the most frequent variable loads only, but not design of dimensioning according to the valid codes. The dynamic analysis verifies a predisposition of the structure to the vibrations and others harmful oscillation effects. The next objective of the thesis was to design a study of a plan curved suspension pedestrian bridge suspended on a single-side. A process of an analysis of these structures has not found in any available references. Especially, the finding of an initial state of a suspension cable has not been documented anywhere and by anybody. The study was analyzed with the same geometry as the cable stayed variation in order to compare both structures. The static and dynamic analysis was performed, too. The last part of the thesis describes the verification of structural solution on a fully functional model in a 1:10 scale, proposed process of the initial state finding, response of the structures on the loading and ultimate load test. The important step is the comparison of the results of the completed physical model and the calculation model.
|
|
|
Experimental determination of the hydrodynamic load of the flooded bridge model
Naiser, Dominik ; Hrdlička, Libor (referee) ; Zubík, Pavel (advisor)
The diploma thesis deals with experimental determination of hydrodynamic load on the overflowed bridge deck model. In the first part of the thesis the author describes the analysis of the problem together with the basic physical laws and principles that are used or assumed in the measurement itself. In the second part the author describes the measurements in the laboratory of the Faculty of Civil Engineering and its gradual processing. At the end of the work are described the results of measurement, their comparison with numerical modeling, other authors and their possible use in practice.
|
|
|
Utilisations of the “Open Dynamics Engine” for modelling of mobile robots
Kovář, Jiří ; Ondroušek, Vít (referee) ; Houška, Pavel (advisor)
This diploma thesis deals with the problems of virtual physical modelling of mobile robots for the needs of their real-time control. To create a virtual physical world, an open-source project OPEN DYNAMICS ENGINE (ODE) was used, the results were displayed facilitating DirectX graphical interface. Simulated systems in ODE were written in C# on Microsoft.NET platform. The properites and qualities in ODE were verified by simulation in several types of simple systems and on a simplified robot model "Kracmera I.". Subsequently, the usability of ODE for its control was being verified.
|
|
|
Numerical Modelling of Flow over Spillway
Holinka, Matouš ; Hodák,, Jiří (referee) ; Jandora, Jan (advisor)
This thesis deals with the solution of numerical modeling. Consequently problems associated with the flow of the water over spillway of the specific water structure. In this case numerical modeling means modeling of fluid movement, which is described by mathematical means. Especially nowadays, when a lot of spillways need to be recalculated, whether it meets the capacity demands, or there is no need to tackle reconstruction. With today's software capabilities there is a wide range of commercial and freeware resources. The numerical model, compared to physical model is less accurate which is, on the otherhand, physical model is usually financially and time-consuming. The following work simulates the behavior of water on the edge of the spillway, in the trough and then behind the trough. The result is a comparison of the water depth in the trough calculated by the numerical and the physical model.
|
|
|
Cutting force analysis when 5-axis milling
Dvořáček, Jan ; Kalivoda, Milan (referee) ; Polzer, Aleš (advisor)
The diploma thesis is focused on machining using the ball-end shank mill. Content of the preliminary part of the work is a shank mill characteristic and a consequent part shows a splitting of ball-end milling cutters, its application, the cutting tool geometry and a characteristic signs of machining. The cutting force model of the ball-end mill is presented as well. A part of proposed model is the conversion of the resultant force too. Practical part is aimed at cutting force analysis of the ball-end mill and the main purpose of this part is a quantification of the cutting force for different work piece tilt angles while milling is performed.
|
|
|
Effect of free surface flow forces on the rectifying element
Höll, Jan ; Sehnal, Jan (referee) ; Zubík, Pavel (advisor)
This diploma thesis deals with the research of the effect of free surface flow forces on the rectifying element and consists of several parts. The first part processes and evaluates the measured values from a physical model. In the next part measurement is checked according to hydraulic laws. In the third part comparison of both methods is created.
|
|
|
Numerical modelling of flow over auxiliary spillways
Kostelecký, Jiří ; Golík,, Pavel (referee) ; Zachoval, Zbyněk (advisor)
The thesis deals with possibilities of numerical modelling of an overflow over selected types of auxiliary spillways and then the possibilities are verified in particular localities. In thesis, there is carried out the determination of capacity of selected spillways by using several methods: the calculation of the overflow equation, one-dimensional and two-dimensional numerical models and physical model. The author created parametric analysis to each single method. Parametric analysis represent various hydraulic conditions. Subsequently, there is possible to express the effect of parametric analysis. The author makes a comparison of water levels received by mentioned methods set out under the specific hydraulic conditions by calibration of each model with the physical model. Finally, author recommends values of all coefficients which have an impact on results of numerical modelling of the flow over selected types of weirs mostly using like auxiliary spillways.
|
|
| |
|
|
Monitoring of the spread of pollution on the physical model of the watercourse
Marek, Ondřej ; Novotná, Jitka (referee) ; Pařílková, Jana (advisor)
On the built physical model of the watercourse, a bachelor's thesis is looking for a suitable substance that would allow simulating and monitoring the pollution transport by the method of electrical impedance spectrometry. Physical model based on the similarity of physical phenomena allowed the application of tracers and measurement of their concentration in selected flow profiles at a defined flow. The measurements were made by measuring apparatus made by the solution of the international project E! 7614 applied research in the EUREKA program as part of its sustainability.
|
|
|
Calculation and optimization of synchronous servomotor reluctance torque.
Kroupa, Martin ; Hájek, Vítězslav (referee) ; Ondrůšek, Čestmír (advisor)
This work is mainly focused on construction and design simulation of synchronous servomotor. This motor is built by 30 permanent magnets which are attached to rotor and solved in Ansoft Maxwell 14 software. The main purpose was to calculate reluctance torque, which is significant during the motor operational mode and its optimization. Ansoft Maxwell 14 can analyze in 2D mode as well as in 3D mode, for analysis it uses method of finite elements. Subjects can be analyzed in static conditions, or in any way of transient movement. Optimization in 2D, where we will change the shape in the area of air gap, will only be used as revision that the reluctance torque is bounded with this factor. The main simulations were supposed to be done in 3D model, where the role of rotation should have been taken in account to the final result. These simulations were replaced by alternative calculation. On behalf of achieved results, the optional rotation is stated in the end of my work.
|
guest ::
