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Simulation anlysis of turbocharger vibrations
Valo, Lukáš ; Lošák, Petr (referee) ; Březina, Lukáš (advisor)
The master thesis deals with computational modeling of a turbocharger vibrations and and assessment of influnce of passive dynamic vibration absorber on vibrations of actuator bracket. The use of dynamic vibration absorber was summarized in the research study. The analysis were performed using finite element method in ANSYS. Several computational models of turbocharger were created with different ways of modeling bolted joints between turbocharger parts. Modal analysis of each model was performed and the results were compared. For the selected model, the response to the kinematic excitation from the internal combustion engine for two load conditions was calculated using harmonic analysis. A simple model of vibration dynamic absorber was applied to the turbocharger model with reduced degrees of freedom and its influnce on vibrations of actuator bracket was investigated. Significant decrease of the maximum acceleration amplitude was achieved in a given frequency range when absorber parameters were optimized.
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Modelling of damping devices in interaction with a structure
Kalina, Martin ; Lehký, David (referee) ; Frantík, Petr (advisor)
The aim of my master’s thesis was to create models of the damping device and observing their behavior in interaction with the structure. First was the construction separately modeled with Java application named FyDiK2D like a model with one degree of freedom. Model of construction takes form like a high, thin rod with full circular cross section. The lower part was restrained into the subsoil. The design was to verify the correct functionality of the model by comparing the analytical and numerical solutions. For capturing the precise behavior of the structure was converted to a multi-stage model. Then the pendulum damper was applied on this construction and found amplitude lies in highest point of multi-stage model. He was then replaced by tuned mass damper. By comparing these amplitudes from both dampers was found which kind of damper is efficient for multi-stage model.
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Vibration energy harvester as a tuned mass damper
Novák, David ; Machů, Zdeněk (referee) ; Rubeš, Ondřej (advisor)
This bachelor thesis it's about vibration energy harvester as a tuned mass damper the design of a vibration generator as a dynamic vibration damper.The work contains a research part, which examines the methods of damping mechanical systems and the influence of the vibrating generator on the vibrating base. Based on this knowledge, equations of motion were derived for the design of the model in the SIMULINK program, where we optimized the parameters for maximizing the obtained electrical power and maximizing the damping effect.
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Dynamic analysis of bridges structures
Prokš, Tomáš ; Salajka, Vlastislav (referee) ; Hradil, Petr (advisor)
The diploma thesis deals with dynamic analysis of cable-stayed steel pedestrian footbridge. The dynamic response of pedestrian-induced vibration was studied. The response of structure exeeded standard acceptance limit. Due to the effect of installed Tuned Mass Damper was studied. Motion equations of single and two degree of freedom model were solved in program MATLAB and the results were compared with numeric model in ANSYS.
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Analysis of dynamical behaviour of slender structures and design of device to reduce vibration
Hanzlík, Tomáš ; Krejsa,, Martin (referee) ; prof. Ing. Alois Materna, CSc., MBA (referee) ; Salajka, Vlastislav (advisor)
Thesis deals with the modeling of pedestrian excitation of structures and obtaining the corresponding dynamic response of the structure. The trend of modern slender structures places more emphasis on the accuracy of modeling pedestrian dynamic excitation, which is difficult because of the intelligent behavior of pedestrians and the biological nature of the modeled pedestrian. First part of the thesis deals with traditional models of pedestrian excitation, based on application of pedestrian ground force to the model of construction. Models are explored on a model of slender footbridge for many different excitation variants in order to explore the specifics of the force excitation application and the structure response calculation. In second part of the thesis biomechanical pedestrian models are developed, including inertial forces, to calculate the pedestrian interaction with the structure. Parametric studies carried out on simplified structural models research the influence of design parameters of biomechanical models on dynamic response. The aim is to obtain a more accurate model of the pedestrian-construction system for refinement of the design of structures. The design of a tuned mass dampers for the reduction of pedestrian induced vibrations is also explored. Tuned mass dampers are devoted to parametric studies that deal with the influence of design parameters of the damper on the efficiency and design requirements of the device. The aim is to explore the design parameters and their influence on the efficient and economical design of the device. In the thesis were developed two biomechanical models, a simple biomechanical model with one vertical degree of freedom and a bipedal model of a human walking. Models have proven a certain degree of interaction when exciting light footbridges by one pedestrian. Bipedal model then also brought a partial insight into the mechanics of walking and the causes of pedestrian contact forces.
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Design of dynamic vibration absorber
Hilšer, Pavel ; Musil, Filip (referee) ; Hadraba, Petr (advisor)
Firs part of bachelor's thesis deals with vibrations, main quantities, damping and methods of solving dynamics models. In second part, description of tuned mass damper is carried out. Then tuned mass damper is designed using matlab, simulik for given entity. Values, calculated using this method are compared with finite element method. After that the entity is realized and measured using modal hammer and accelerometer. Calculated values are compared with values measured values.
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Analysis of tuned mass damper
Jurečka, Martin ; Rubeš, Ondřej (referee) ; Kšica, Filip (advisor)
Complex mechanical structures are often exposed to external influences that can cause excessive vibrations, which can limit their ability to perform their function or affect operational safety. Tuned mass dampers, which are focus of this thesis are very often used to avoid such vibrations. The firts part of the thesis is focused on the research of the principle of tuned mass damper and its use in engineering practice. In the secound part obtained knowlage is used to create a mathematical model of the selected mechanical system and then to implement a suitably designed tuned mass damper to damp unwanted vibrations. Part of the work i also to build a real model of the tuned mass damper, which will demonstrate its function.
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Vibration energy harvester as a tuned mass damper
Novák, David ; Machů, Zdeněk (referee) ; Rubeš, Ondřej (advisor)
This bachelor thesis it's about vibration energy harvester as a tuned mass damper the design of a vibration generator as a dynamic vibration damper.The work contains a research part, which examines the methods of damping mechanical systems and the influence of the vibrating generator on the vibrating base. Based on this knowledge, equations of motion were derived for the design of the model in the SIMULINK program, where we optimized the parameters for maximizing the obtained electrical power and maximizing the damping effect.
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