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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.
461

Baja SAE Vehicle Design / Návrh vozidla Baja SAE

Hajdušek, Zdeněk January 2012 (has links)
This master’s thesis describes the design of the Baja SAE vehicle according to the applicable rules. In the beginning is the work focused on search competing vehicles and subsequently on design the first Baja SAE vehicle in the Czech republic. This thesis is systematically divided into chapters according process to the vehicle design. The main part of a master's thesis is design of axle kinematics in software Adams and frame design. The model was designed in Catia V5. The frame was analysed of torsional stiffness and stress in software ANSYS.
462

Návrh stavitelného stabilizátoru přední nápravy vozu Formule student / Design of Formula Student Front Axle Adjustable Stabilizer

Ševčík, Jan January 2012 (has links)
Diploma thesis focuses to design anti roll-bar for Formula Student car Dragon II build in FME. This work follows the proposal anti roll-bar car Dragon I of Jan Krasula. Task of this work is analyses last design, introduce more effective method treatment, create own design with parameters which will be better then last design. An integral part design is prepare manufacture documentation which will be base for manufacture of this komponent
463

Zařízení pro měření torzní tuhosti karoserie / Chassis Torsional Stiffness Measurement Stand

Kudr, Jan January 2013 (has links)
Those theses describe torsional stiffness car chassis. Here is write short knowledge about various type of measuring, explain impact torsional stiffness on car handling. Target of this theses is work out structural proposal of device for measuring torsional stiffness car chassis, suitable method of measuring, calculate measurement mistake and provisional cost calculation.
464

Měření charakteristik zkrutných tyčí a stabilizátorů / Measurement of torsion bars and stabilizers

Bláha, David January 2014 (has links)
This diploma thesis deals with the measurement of the anti-roll bar characteristics. The target of this thesis is to design a device for measuring of torsional stiffness of the automobile stabilizer bars, design a measuring sequence for detection values subsequently used to calculate the stiffness, and calculate the total measuring error. The measuring device is designed for the needs of the Institute of Automotive Engineering of FME BUT.
465

Konstrukční návrh trubkového rámu Formule Student / Formula Student Tubular Frame Design

Ratiborský, Pavel January 2014 (has links)
This thesis deals with the design of the tubular frame for the Formula Student car competition. The first part is a brief introduction to the competition and used variants of frames. The main part starts with a list of restrictions by the rules and other necessary installation components. The central part is devoted to the draft modifications and their assessment in terms of torsional stiffness by FEM analysis. The final section presents the resulting frame design with respect to the required properties. The work is concluded final evaluation.
466

Stanovení závislostí pro vyhodnocování výsledků měření tuhosti pryžového kloubu / Determination of Dependencies for Evaluation of Stiffness Measurements of Rubber Bearings

Beseda, Vojtěch January 2014 (has links)
The thesis deals with analysis of rigidity of rubber joint measurements. Characteristic, usage and behaviour of a rubber is described in the first part of the work. The following chapter describes problems and analyse production technology of the given component. The work continues by a preparation of several tests established based on information provided in the first chapter and from requirements of company. At the end, correlations and recommendations for appropriate measurement are concluded based on acquired data. The thesis is closed by a technological and economical evaluation which presents required cost for preparation, realization and analysis of tests.
467

Torzní tuhost rámu vozidla Formule Student / Torsional Stiffness of the Formula Student Chassis

Petro, Pavol January 2016 (has links)
The master´s thesis is focused on chassis design of Formula Student car. It´s describes not only design of frame but also mounting of suspension components like arms, rockers and dampers. During whole design process was using finite elements method calculations, to achieve determined value of torsional stiffness and prevent local deformation of frame structure during drive. Value of torsional stiffness is also verificated by measurement and in last chapter is described influence of torsional stiffness on vehicle dynamics.
468

Výpočtová analýza stojanu pro horizontální vyvrtávací centrum / Computational analysis of column for horizontal boring centre

Fargač, Michal January 2016 (has links)
The theoretical study of this thesis deals with different approaches that can be used to optimize the topology of various structures. Main attributes and principles which they are based on of individual methods are discussed. The first point of the practical part is to design the model for computational analysis of stand and other machining centre parts based on real machine TOS FU. Afterwards, the model is analyzed to determine the dynamic characteristic of the machine. Subsequently, several changes of the stand design are performed in order to improve the dynamic behavior. Eventually, new stand kernel is designed which aims to enhance these dynamic characteristic. This model is analyzed again and the results are compared with the original form of the machining centre.
469

Estimation de la pression aortique à l'aide de l'imagerie par résonance magnétique : développement d'un modèle biomécanique d'écoulement / Estimation of aortic blood pressure using Magnetic Resonance Imaging and blood flow modeling

Rachid, Khalil 17 September 2018 (has links)
Les maladies cardiovasculaires représentent la première cause de mortalité dans le monde. L’hypertension artérielle et l’hypertrophie du ventricule gauche en constituent deux facteurs de risque souvent asymptomatiques. Dans ce contexte, la pression aortique s’impose comme un indicateur de la santé cardiovasculaire reflétant non seulement les propriétés biomécaniques des artères centrales mais aussi la post-charge ventriculaire. La mesure de ce paramètre hémodynamique est donc cruciale pour le diagnostic et la prise en charge thérapeutique. L’objectif de ce travail est d’estimer non-invasivement la pression aortique en couplant l’Imagerie par Résonance Magnétique Cardiovasculaire (IRM-CV) à la modélisation de l’écoulement sanguin. Nous avons ainsi opté pour un modèle biomécanique unidimensionnel (1D) réduit, prenant en compte l’interaction du sang avec la paroi élastique de l’aorte. Ce segment 1D est couplé en sortie à un modèle Windkessel, dit 0D, modélisant l’ensemble du réseau vasculaire en aval de l’aorte. Les paramètres locaux du modèle 1D ainsi que ses conditions aux limites (conditions d'entrée et paramètres du modèle 0D) sont déterminés à partir des données acquises non-invasivement par IRM-CV. Cela permettrait des prédictions 1D spécifiques à chaque sujet/patient. Nous avons évalué la validité du modèle sur des fantômes d’aorte saine et pathologique. Un banc expérimental compatible avec l’IRM a été mis en œuvre; il reproduit au mieux l’écoulement aortique in vivo. Des mesures de pression invasives ont été confrontées à celles prédites par le modèle 1D. Nous avons également évalué la sensibilité du modèle 1D aux paramètres d’entrée. / Cardiovascular (CV) diseases remain the most common cause of death worldwide. Hypertension and left ventricle hypertrophy are two major risk factors associated to such diseases. In this context, aortic blood pressure is considered as a biomarker of increased CV risk and, more generally, a CV health indicator. In fact, it encodes information about biomechanical properties of central elastic arteries and represents left ventricle afterload. Assessment of this hemodynamic parameter is thus crucial for CV disease diagnosis and for evaluating therapeutic benefits. The aim of this work is to non-invasively assess the aortic blood pressure by coupling CV Magnetic Resonance Imaging (CV-MRI) to blood flow modeling. We thus developed a reduced one-dimensional (1D) flow model taking into account the fluid-structure interaction. A Windkessel (or zero-dimensional (0D)) model describing the arterial tree downstream of the aorta was coupled to the 1D segment. Both 1D model parameters and boundary conditions (inlet condition and 0D model parameters) were non-invasively determined using CV-MRI data. This gives the opportunity of deriving subject- or patient-specific blood flow models. To validate our approach, we applied our model to both healthy and pathologic aorta phantoms. Each phantom was mounted in an experimental setup reproducing as well as possible in vivo aortic flow and compatible with the MRI environment. Invasive pressure recording was compared to predicted pressure waves. We also performed a sensitivity analysis of our reduced 1D model.
470

Otimização de uma metaestrutura com rigidez não linear para atenuação de vibração axial /

Vasconcellos, Diego Pereira January 2020 (has links)
Orientador: Marcos Silveira / Resumo: O objetivo deste trabalho é explorar a atenuação da vibração de uma metaestrutura por meio da adição de absorvedores de forma periódica. Além disso é explorada a atenuação da vibração de uma metaestrutura quando um absorvedor com rigidez cúbica não linear é incluído sem aumentar a massa total. As metaestruturas, e especificamente as estruturas periódicas, apresentam características interessantes para atenuação da vibração que não são encontradas em estruturas clássicas. Estas características foram exploradas para aplicações automotivas e aeroespaciais, entre outras, pois estruturas com baixa massa são fundamentais para essas indústrias. Também é desejável manter baixos níveis de vibração em uma ampla faixa de frequência. Foi demonstrado que a adição de absorvedores de vibração em um arranjo periódico pode fornecer atenuação da vibração para entrada de choque sem aumentar a massa total de uma estrutura. Neste trabalho, a resposta dinâmica do sistema proposto é comparada a uma metaestrutura base sem absorvedores e uma metaestrutura com absorvedores lineares para entrada harmônica através da avaliação da norma H2 da resposta em frequência. Um procedimento de otimização é mostrado para encontrar a posição ideal e os coeficientes de rigidez do absorvedor não linear. A resposta dinâmica do sistema ideal é obtida numericamente e mostra que a adição de um absorvedor não linear pode melhorar a atenuação da vibração. / Abstract: The objective of this work is to explore the vibration attenuation of a metastructure by periodically adding absorbers, and the vibration attenuation of a metastructure is explored when a nonlinear cubic stiffness absorber is included without increasing the total mass. Metastructures, and specifically periodic structures, present interesting characteristics for vibration attenuation that are not found in classical structures. These characteristics have been explored for automotive and aerospace applications, among others, as structures with low mass are paramount for these industries, and keeping low vibration levels in wide frequency range is also desirable. It has been shown that the addition of vibration absorbers in a periodic arrangement can provide vibration attenuation for shock input without increasing the total mass of a structure. In this work, the dynamical response of the proposed system is compared to a base metastructure without absorbers and a metastructure with linear absorbers for harmonic input via the evaluation of the H2 norm of the frequency response. An optimisation procedure is shown to find the optimal position and stiffness coefficients of the nonlinear absorber. The dynamical response of the optimal system are obtained numerically, and shows that the addition of one nonlinear absorber can improve vibration attenuation. / Mestre

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