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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Stanovení modálních charakteristik celokompozitového křídla s využitím MKP metod / Determination of modal characteristics of composite wings using FEM

Churý, Tomáš January 2015 (has links)
The diploma thesis deals with the creation of a detail FEM model all-composite wing of glider. Reduction created FEM model of the beam model. The models are calculated natural frequencies, vibration shapes wings and then subsequently compared the results of analyzes of both models.
102

Výpočet zatížení, analýza pevnosti a simulace nárazu ptáka pro kompozitní náběžné hrany křídla / Loads calculation, stress analysis and bird strike simulation of a composite wing leading edge

Zubrytski, Raman January 2015 (has links)
Tato diplomová práce se zaměřuje na stanovení geometrických a materiálových parametrů konstrukce slotu letadla B737-200. V této práci je vypracovaný návrh kompozitového slotu s ohledem na dané zatěžovací případy, včetně tzv. “bird strike”. Analytické výpočty jsou ověřené metodou konečných prvků (MKP) v programech MSC.Nastran/Patran, MSC.Dytran
103

Akcelerace částicových rojů PSO pomocí GPU / Particle Swarm Optimization on GPUs

Záň, Drahoslav January 2013 (has links)
This thesis deals with a population based stochastic optimization technique PSO (Particle Swarm Optimization) and its acceleration. This simple, but very effective technique is designed for solving difficult multidimensional problems in a wide range of applications. The aim of this work is to develop a parallel implementation of this algorithm with an emphasis on acceleration of finding a solution. For this purpose, a graphics card (GPU) providing massive performance was chosen. To evaluate the benefits of the proposed implementation, a CPU and GPU implementation were created for solving a problem derived from the known NP-hard Knapsack problem. The GPU application shows 5 times average and almost 10 times the maximum speedup of computation compared to an optimized CPU application, which it is based on.
104

Návrh uskladňovací nádrže / Design of storage tank

Sedmidubský, Petr January 2016 (has links)
The master thesis deals with design of storage tank for nitric acid. The first chapter introduces the problems of design, manufacture and operation of the storage tanks. The next section describes design calculation of storage tank according to standard EN 14015. Control of design calculation is performed by analysis FEM in program ANSYS Workbench 16.2. Thesis also includes basic drawing of storage tank.
105

Simulace šíření ultrazvukových vln v celokompozitních tenkostěnných konstrukcích / Simulation of ultrasonic wave in the composite aircraft structures

Cimrhanzl, Jan January 2016 (has links)
V této diplomové práci jsou popsané SHM metody používané v letectví a dále jsou udělány MKP simulace šíření ultrazvoukových vln v celokompozitním tenkostěnném materiálu používaném u leteckých konstrukcí. Pro simulaci byla zvolena SHM metoda nazývaná pitch-catch. Simulace byla provedena na dvou různých kompozitových materiálech a každý z nich byl testován třemí různými konfiguracemi s trhlinou a jednou konfigurací bez trhliny. Jako prepocessor byl použit MSC.Patran a jako post processory byli použity MSC.Nastran a MSC.Dytran, jejichž výsledky byli na závěr porovnány. Simulace prokázali, že rychlost šíření a amplituda vln šířících se v simulovaném panelu je trhlinami ovlivněna. Při konfiguracích s trhlinami rychlost šíření i amplituda vln byli menší, než v případě bez trhliny. Jako vhodnější post processor při MKP simulacích se ukázal MSC.Nastran, jehož výsledky byli přesnější a zárověň bylo i snažší správně odečítat hodnoty dat z grafů pro podrobnější pozorování šíření vln.
106

Posouzení vlivu tuhosti ložiskových štítů a kvality vyvážení na vibrace synchronního generátoru / Effect of the bearing shields stiffness and balance quality on synchronous generator vibration

Čepica, Vojtěch January 2016 (has links)
The main focus of my master thesis is the assessment of effects of the bearing shields stiffness and balance quality on synchronous generator vibration. The incentive of writing the thesis is the problematic situation, which is characterized by synchronous generator vibration. The aim of my thesis is to variate shields stiffness and to find out the dependence of vibration on stiffness during nominal speed. I have used the program ANSYS based on finite element method to solve this problem.
107

Rám valníkového přívěsu / Platform trailer chassis

Huf, Jiří January 2016 (has links)
This thesis deals with stress analysis of tandem platform trailer TVL10. The first part is devoted to description of trailers and their parts. The second part presents and evaluates the results of measuring acceleration and vibration of the trailer, and it describes the concrete chassis of a tandem trailer. There is included an analysis of the existing structure, design modifications and stress calculation and evaluation of newly designed chassis structure. The thesis is developed in cooperation with PANAV, a.s.
108

Návrh vyhřívaného atypického stolu pro 3D tiskárnu / Design of atypical heated bed for 3D printer

Strnad, Jan January 2016 (has links)
This diploma thesis deals with an atypical heated bed for FDM 3D printer. It presents the most commonly used ways of heating and the chosen variant of the heated beds are realized by powerful resistors. There are also discussed three ways of placement of resistors on the desktop motherboards that are modeled in Autodesk Inventor Professional 2016 and exported to Autodesk Fusion 360, where FEM calculations are made. Optimal alternative is made and tested. The test results are compared with the results of thermal simulations in Autodesk Fusion 360.
109

Implicitní a explicitní metoda v nelineární dynamice / Implicit and Explicit Method in nonlinear Dynamics

Vaněčková, Adéla January 2017 (has links)
The final thesis „Explicit and Implicit methods in nonlinear dynamics“ deals with the issue of geometrical and physical nonlinear analysis of structures exposed to seismic loading by the methods of direct integration of equations of motion. Solution by the explicit and the implicit method is compared for three material models. While the differences between the results of the explicit method and the implicit Newmark method are small as expected, the differences are substantial between the results of different material models. However, these differences are explained and they are in full concordance with the theoretical assumptions for the pertinent material models. The conclusion of the final thesis is check of correctness of the results of the new module of the program system RFEM for both tested numerical methods and all three analyzed material models. (linear elastic, plastic Drucker-Prager and the Mazars damage model). With sufficient precision of results, both explicit and implicit numerical methods showed to be suitable for seismic analysis. The implicit method can provide several times faster calculation than the explicit one, but the determination of the optimal time step is problematic and time consuming, so the suitability of use of both methods for seismic analysis is comparable.
110

Mechanická analýza celodřevěných konstrukčních spojů

Milch, Jaromír January 2016 (has links)
Traditional all wooden construction joints are currently widely used when historically valuable buildings are being reconstructed. These construction joints are indispensable and irreplaceable in order to maintain cultural heritage for our future generations. They underline the importance of the wooden structures and buildings, which in many cases might have incalculable historical, artistic as well as financial value. However, increased interest brings many challenges and potential risks that need to be taken into account and eliminated by appropriate solution(s). Adequate employment of these wooden joints requires a research-based approaches, which allows proper implementation within existing constructions while maintaining its reliability and safety. Main aim of preset doctoral thesis was to contribute to the development of suitable methods for analyzing mechanical behavior of all wooden construction joints, especially dowel joints, which are mainly used for reconstruction of damaged wooden elements or their parts. For such purposes, various methods (models), based on combination of theoretical, experimental and numerical approaches, has been used. This work was divided to a) basic mechanical tests of solid wood and b) complex finite element analyses of all wooden joints and constructions. Mechanical behavior in tension, compression, bending and shear was tested on small clear specimens made of spruce (Picea abies L. Karst.), beech (Fagus sylvatica L.) and oak (Quercus robur L.). Analyzed species were chosen as a most important historical as well as present European building materials. Mechanical response was captured using cameras in stereovision 3D configuration in order to obtain full-field displacement and strain data sets. Based on obtained data, material characteristics were determined and verified in frame of assembled material models for finite element analyses (FEA). Verified elasto-plastic material models were used as main material inputs for complex FEA for evaluation of mechanical response of joints and constructions subjected to load. Furthermore, material characteristics were used in calculations of mechanical properties of dowel joints. Numerical analyses were done using ANSYS software with parametric design language (APDL). Experimental results of single-shear dowel joints are in agreement with theoretical approach according to European Yield Method (EYM) theory, which was used for determination of joints and fasteners yield strength. FEA proved that assembled elasto-plastic material models can predict the ultimate strength even in complex tasks, and therefore, can be used for more reliable designing of wooden constructions and joints in variety of configurations.

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