• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 319
  • 27
  • 6
  • 2
  • 1
  • 1
  • Tagged with
  • 357
  • 287
  • 127
  • 125
  • 78
  • 73
  • 68
  • 67
  • 65
  • 65
  • 64
  • 48
  • 34
  • 32
  • 30
  • 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.
201

Technický demonstrátor čtyřdobého zážehového nepřeplňovaného motoru / Technology demonstrator of a four-stroke naturally aspirated spark-ignition engine

Chovanec, Stanislav January 2018 (has links)
Master’s thesis deals with design of single cylinder engine which is technology demonstrator of four cylinder naturally aspirated spark ignition engine Mazda Skyactiv-G. Outset of this thesis deals with construction of modern naturally aspirated engines and with comparison of their parameters. Computational part consists of forces in crank mechanism. These calculations are later used in FEM analysis of connecting rod.
202

Konstrukční návrh nábojů kol vozidla / Vehicle Wheel Hubs Design

Mohyla, Daniel January 2018 (has links)
This diploma thesis deals with design of a wheel hub assembly for a Formula Student vehicle. First part of this thesis is dedicated as an introduction to the Formula Student competition and serves as a summary of design solutions for wheel hubs with a focus on open wheel vehicles. Second part deals with description of a problem and summarizes necessary knowledge and information to solve given problem. Third part is devoted to CAD modelling in software PTC Creo parametric. This model is then analysed using finite element method. Last part of this thesis is a discussion about achieved results and discussion about further potential improvements is carried out.
203

Deformačně a napěťová analýza fixátoru dolní končetiny Orthofix / Stress - strain analysis of inferios limb with fixator type Orthofix

Mrázek, Michal January 2008 (has links)
This diploma thesis aims to create a stress strain analysis of Orthofix external fixator applied to lower limb. The introduction summarizes the background research in available scientific publications, targetting the alternatives of treatment, namely application and fixation solutions of long bones. Furthermore parametric models of the fixator and tibia are created in CAD system CATIA. The fixator model enables to create different geometric variations simulating possible fixator settings and moment load in the range of 1-10 Nm. These geometric and loading states of fixator are solved via FEM in ANSYS. Single versions of the states of Orthofix fixator are then subjected to the stress strain analysis.
204

Výpočtová simulace vibrací gumového silentbloku / Computational simulation of vibrations of rubber damper

Krupa, Lukáš January 2018 (has links)
This thesis deals with computational modelling of rubber damper using Finite element method (FEM). This thesis includes experimental measurement of material properties of rubber subjected to static and dynamic loading and their implementation into viscoelastic and hyperelastic material models with respect to given task. Dependance of dynamic stiffness on loading frequency obtained from the simulation is validated with experimental measurement. In the end the difference between results is investigated and possible causes of that are introduced.
205

Simulace hluku vyzařovaného jednostupňovou převodovkou / Simulation of Noise Emitted by a Single-stage Gearbox

Motl, Daniel January 2018 (has links)
The level of noise and vibration of gearboxes is one of the most important parameters for today´s customers. This thesis deals with mathematical acoustic behavior modelling and its contribution to the gearbox design using finite element method. The process is presented at three computations models. Two of those were validated with experimental measurement. Acoustic analysis were performed with software FFT ACTRAN.
206

Výpočtová analýza vlivu výrobních defektů na porušení keramické pěny při mechanickém zatížení / Computational analysis of the influence of initial defects on the ceramic foam failure upon mechanical loading

Papšík, Roman January 2019 (has links)
The thesis deals with computational modelling of ceramic foams and analysis of influence of structural manufacturing defects (like broken struts, closed pores and material clumps) have on foam strength. Model of foam geometry was discretized using beam elements in order to decrease computational cost. In place where several struct join, rigid beam element was used so that the increased stiffness is better modelled. Closed walls of pores were modelled and discretised by shell elements. Influence of loading direction was analysed on foams containing no defects and then influence of amount of defects in foam on strength was further analysed. Highest strength show foams created by cells whose structs are oriented in direction of loading. These were losing strength most rapidly. Foam with structure of rhombic dodecahedral cell was least influenced by presence of closed pore defects but it also showed lowest strength even without defects. Cells with struts oriented in direction of loading experienced biggest drop in strength. Kelvin cell is a compromise. It was shown that difference in strength of strut with constant and varying cross-section is tenths of percent.
207

Simulační analýza nosiče předního kola formulového vozidla / Formula Car Front Wheel Carrier Simulation Analysis

Gach, Jakub January 2019 (has links)
This Master’s thesis is focused on the suspension of the front wheel, more accurately for specific part, upright. It describes the basic requirements for construction, distribution of uprights, their method of production and types of materials used. It briefly mentions topology optimization and its two optimization methods. Also deals with vehicle dynamics for driving conditions – standing vehicle, braking and cornering. In the practical part, the work is focused on determining the load effects on the upright during the aforementioned driving conditions using MBS software. At the end of the work, FEM stress and deformation analyses are performed for loading on the wheel side and on the suspension side, which are then compared and evaluated.
208

Manipulátor / Manipulator

Peška, Dalibor January 2019 (has links)
The goal of this thesis is to develop a concept of a casting manipulator. The manipulator is intended for manipulation of very precise casts weighing up to 2 tons. The manipulator performs rotary movement in range 90 degrees. In this thesis a strength calculation, solution of the individual structural units and necessary drawings are presented.
209

Numerická simulace porušování keramických pěn při mechanickém zatížení / Numerical simulation of failure of ceramic foams upon mechanical loading

Hanák, Jiří January 2019 (has links)
The master’s thesis deals with a numerical simulation of failure of ceramic foams with open-cell structure and with understanding of conditions required for the failure of the structure under various mechanical loading conditions. To this purpose, the so-called stress-energy coupled criterion was utilized. The motivation for this thesis was to create a model able of the most accurate prediction of the ceramic foam strength in comparison with experimental observations. First part of the thesis is focused on the theoretical background required for solving the problem. More specifically there are mentioned methods of the foam material modelling, Linear Elastic Fracture Mechanic (LEFM) and coupled stress-energy criterion used for definition of the crack initiation. In the second part of the thesis, numerical Finite Element Analyses (FEA) whose main purpose was to determine critical conditions necessary for the initiation of strut failure within the foam structure, were performed. These pieces of knowledge were then used for creation of the numerical simulation algorithm of the mechanical test of foam material with regular cell pattern. Outputs of numerical simulations were at the end of this work compared with experimental results (of the compression test) made on the real Al_2 O_3 foams prepared by 3D printing technology and provided by the Institute of Physics of Materials Czech Academy of Science. It can be concluded that a good agreement between results of both approaches was reached and the prediction of the ceramic foam mechanical strength using the developed model is in the meanwhile the most accurate estimation from recently published approaches.
210

Návrh ochranného rámu kabiny ROPS / Design of the ROPS protective frame

Zimek, Rostislav January 2019 (has links)
This thesis deals with the design of the protective frame protecting occupants in rollover (ROPS). The creation of the calculation model, in order to perform a stress-strain analysis of the frame under the conditions of the homologation test. Execution modal analysis with the inclusion of the mass of the auxiliary device. A motion for a protective frame is designed so that it can be subjected to destructive test according to standards ČSN EN ISO 3471. The strength and modal analysis was carried out using the finite element method (FEM). The diploma thesis was conducted in cooperation with the company, the Tatra Truck a.s.

Page generated in 1.3955 seconds