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Strength design of the aircraft spur
Profota, Martin ; Vosynek, Petr (referee) ; Vrbka, Jan (advisor)
This master thesis deals with computational stress-strain analysis of the tailskid of airplane L410 NG with main focus firstly the check current design of the tailskid and then the design another design solution with the able to absorb as much as possible the deformation energy. Solution of this problem is performed using computational modeling utilizing numerical simulation of quasi-static and crash deformation load of the tailskid with using explicit Finite Element Method (FEM) in program ABAQUS v6.14. After the introduction with problem situation and tailskid assembly introductory part is devoted to the research study of various designs of the tailskid for different types of airplanes. There follows these theoretical general principles of thin-walled structures and buckling of them. Before the creating of the computational model itself, the explicit form of the Finite Element Method is better described. The conclusion of this thesis deals with the mutual comparison of the most advantageous design variants of the tailskid and the selection of the most suitable one of them for the airplane L410 NG.
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Optimization of aluminium casting process using numerical simulation
Kolařík, Martin ; Lána, Ivo (referee) ; Krutiš, Vladimír (advisor)
The master’s thesis deals with the analysis of casting technology of the selected aluminium casting. It is a casting of a part of CNC milling machine and it is cast by gravity casting into a permanent mold. The defects which are the cause of a high percentage of nonconforming production were analyzed. Furthermore, the master’s thesis includes a complete analysis of filling and solidification of this casting in the ProCast simulation program. Numerical simulation results are verified and improved. Then the causes of problematic casting defects are proven on several calculated variants. Measures are proposed to minimize the tendency to produce castings with defects leading to nonconforming production.
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Use of Numerical Simulation to Optimize Wax Patterns Production
Kosour, Vojtěch ; Elbel, Tomáš (referee) ; Nová, Iva (referee) ; Horáček, Milan (advisor)
Production of wax pattern model by injection machine is a one of the key phases of Investment casting process. The thesis deals with the development of numerical simulation wax blend injection in to metal die. The possibilities of selection simulation software – ProCast and Cadmould are described in the relation to numerical predictions of wax injection. Creating of material database of selected wax blends is described. The prototype simulations of die filling are made. The special testing die are designed a used for created simulations. The measurements of initial conditions are mentioned.
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Cavitating jet
Kotoulová, Helena ; Kozák, Jiří (referee) ; Rudolf, Pavel (advisor)
Předložená diplomová práce se zabývá kavitujícím paprskem a je rozdělena do tří hlavních částí. Teoretická část popisuje základní principy kavitace a její negativní účinky na povrch obtékaných těles (např. hydraulických strojů). Rozsáhlá kapitola je také věnována popisu samotného kavitujícího paprsku včetně mechanismů jeho vzniku, růstu a kolapsu. Další podkapitola je zaměřena na modely kavitační eroze, které mají velký význam pro predikci kavitační eroze ve fázi výpočtové simulace. V experimentální části je popsáno testování vzorku mědi inspirované normou ASTM G134 a následné vytvoření grafů kumulativního hmotnostního úbytku a rychlosti úbytku hmotnosti. Dále byla také provedena vizualizace pomocí vysokorychlostní kamery, aby bylo možné podrobně prozkoumat dynamické chování kavitujícího paprsku. Poslední část je zaměřena na numerické simulace pomocí výpočtového modelování proudění, tzv. Computational Fluid Dynamics (CFD), a na predikci kavitační eroze. Z důvodu optimalizace úlohy bylo provedeno více výpočtů na různých typech sítí s různými modely turbulence. Následně byly výsledky ze simulací vyhodnoceny a společně s výsledky z experimentu byly použity pro predikci kavitační eroze.
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Problems of critical wall narrowing in high pressure hydroforming
Drška, Jan ; Řiháček, Jan (referee) ; Lidmila, Zdeněk (advisor)
Bachelor's thesis deals with narrowing metal sheet wall by high-pressure-fluid forming technology on a practical example. This thesis is working on an issue from practice while using a non-standard problem solving method. Theoretical part outlines classical methods of hydroforming and the theories of sheet metal forming. Practical part consists of proposed solution and an elaborated simulation. Subsequently is described the ideal machine for hydroforming and technological procedure. Last part is devoted to technical and economical evaluation.
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Manufacturing of a Component by Using Hydroforming Technology and Its Optimization
Harant, Martin ; Peterková, Eva (referee) ; Řiháček, Jan (advisor)
The project deals with analysis and optimization of the geometry of the stamped part produced by the pillow hydroforming. The blank consists of two sheets of steel DC01, which is welded by laser beam. The forming process can cause excessive thinning and cracking of the part. By evaluation of mechanical tests is created material model, which is the basis for numerical simulation created in software PAM-STAMP. The outputs are analysis which provide information about critical points, failure pressure, limiting deformations and prediction of springback. Validity of the numerical simulation is verified by comparison with the experimentally obtained data. The comparative criterions are the failure pressure and the material thickness at various locations. Based on the results of the numerical simulation, the optimization of the geometry is created. The optimization uses different values of radius at the crack point.
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Analysis of fracture of quasibrittle materials using numerical modelling and acoustic/electromagnetic emission
Vodák, Ondřej ; Vořechovský, Miroslav (referee) ; Veselý, Václav (advisor)
This master thesis gives overview of non-destructive tests of concrete and provides detailed information concerning the acoustic and electromagnetic emission during monitoring of concrete failure. Conducted loading tests of plain concrete specimens are described in the thesis together with the performed numerical simulations of these tests in the software ATENA. The simulation results of concrete failure are analysed in detail and compared with the experimental results recording failure processes with the help of acoustic and electromagnetic emission. The majority of simulation results in software ATENA 3D show good agreement with the recorded data.
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Car cabin passive cooling system performance study
Viščor, Petr ; Hejčík, Jiří (referee) ; Fišer, Jan (advisor)
The work is focused on issue of passive cooling in a cabin of a car. The basic principles and mechanisms of heat transfer are described in the theoretical part and the quality of cabin environment in terms of thermal comfort and air quality is discussed as well. Next part of the work describing the principles of ventilation and air conditioning of cabins and possible methods of passive cooling are discussed. Passive cooling means decrease of temperature of cars interior, without need of energy supply from car battery, or fuel. The last part of the work includes numerical simulation of selected methods of passive cooling using the THESEUS-FE 3.0 software. Simulations were performed on model of Volkswagen Polo car and primarily were focused on testing of functionality of various methods of passive cooling.
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The use of hydraulic disc brakes for road bikes
Dvořáková, Barbora ; Lošák, Petr (referee) ; Šebek, František (advisor)
This bachelor's thesis is focused on the usage of hydraulic disc brakes on road bikes. The thesis is divided into two parts. In the first part, there is a research focused on differences in construction and properties of hydraulic disc brakes in comparison with rim brakes. The main emphasis is placed on evaluating all advantages and disad-vantages of the hydraulic disc brakes in comparison with rim brakes. Evaluation is conducted both from the functional point of view and user point of view with taking different requirements of both recreational level cyclist and professional cyclist into account. The aim of the second part is the numerical simulation of loading of the frame and fork for both types of brakes. The goal of this part is an overall assessment of suitability of hydraulic disc brakes for the road bikes.
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