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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.
1

Analysis of effects and consequences of constructing Inductive Power Transfer Systems in road infrastructure. : A case study for the Stockholm region (Sweden).

Cordoba Ledesma, Enrique January 2015 (has links)
The continuous growth in road transportation demand requires the development towards sustainable strategies. The concept of Smart Roads is arising as a convergence of technologies that will lead the mobility by road into a more efficient and interactive system between infrastructure, environment and vehicles. Within this context, e-mobility appears as one of the key components. The implementation of e-mobility based on Electric Vehicles (EVs) has been restricted by numerous shortcomings such as their driving range, the battery size, the dependence on charging stations and the time required for its charging. However, the electrification of the road infrastructure, which will enable a dynamic charging of the EVs while driving, is becoming a potential solution to overcome these deficiencies. This study aims to contribute for the future introduction of electrified roads (eRoads) into the current network, by focusing on the effects and consequences of embedding Inductive Power Transfer (IPT) systems in the road infrastructure. A structural design of an eRoad is conducted through a Finite Elements Analysis (FEA) by analysing the behaviour of a pavement structure based on Swedish conditions subjected to traffic loading. Valuable conclusions can be displayed from this analysis and thus, a summary concerning considerations and effects over the design, construction and maintenance of eRoads can be built. Nevertheless, this analysis must be complemented and coordinated from a lifetime perspective to reach the social, environmental and economic requirements related to the development of road infrastructure nowadays. Hence, a guideline from a life cycle approach is stated over the integration of eRoads in order to enable the assessment of the infrastructure during its different phases. To be sustainable, the development of road infrastructure must reach not just structural and appropriate performance requirements, but also preserve the environmental and economic impact. This thesis pretends to combine all these aspects as a state of the art, providing a basis that stands out the most relevant issues related to the feasible implementation of eRoads in the mid-long term.
2

Rám klece výtahu / Frame of the lift car

Mikšík, Libor January 2013 (has links)
This master’s thesis deals with the strength analysisby frame lift cage with lift capacity of 675 kg used the Finite Element Method (FEM). Furtheris performed the calculation of the guideanchoring instituted for this steel structure and the strength analysis of the used guides according to norm ČSN EN 81-1. The thesis also includes the drawing of the frame lift cage.
3

Análise teórico-experimental da influência da força normal em nós de pórtico externos de concreto armado / Theoretical-experimental analysis of the influence of normal force on the exterior reinforced concrete joints behavior

Haach, Vladimir Guilherme 30 June 2005 (has links)
Os nós de pórtico são locais de mudança de direção do eixo da estrutura, logo são regiões descontínuas, ou seja, as hipóteses de Bernoulli de deformações lineares ao longo da seção transversal não são válidas. Sendo assim os métodos convencionais de dimensionamento não se aplicam a esta região. Além disso, são regiões problemáticas também do ponto de vista construtivo, por apresentarem geralmente uma alta taxa de armadura em dimensões reduzidas. Diversas são as variáveis que influenciam o comportamento dos nós de pórtico externos, dentre elas está a força normal aplicada no pilar. Esta variável foi observada por diversos pesquisadores (Parker & Bullman, 1997; Scott et al., 1999; Hwang & Lee, 1999; Bakir & Boduroglu, 2002; Hegger et al., 2003), porém com grandes divergências de opiniões sobre sua influência na ligação. Desta forma, este trabalho visa analisar a influência da força normal no comportamento de nós de pórtico externos de concreto armado. Neste sentido é apresentada uma extensa pesquisa bibliográfica abordando trabalhos experimentais e modelos teóricos propostos para o dimensionamento dos nós (bielas e tirantes). Inserindo-se no contexto é analisada a influência da força normal nos nós de pórtico externos por meio da análise experimental de quatro ligações sujeitas a diferentes níveis de força normal, da comparação com os modelos teóricos apresentados e da simulação numérica do nó de pórtico com o aplicativo ABAQUS, utilizando como ferramenta básica o método dos elementos finitos (MEF) / The joints are points where the structures’ axes swerving, therefore they are discontinuous regions, it means, Bernoulli’s hypotheses of linear deformations over the section are not valid. Consequently the conventional methods of design are not applied to this region. Moreover, the joints are also problematic regions to build, for generally presenting one high reinforcement ratio in reduced geometricals dimensions. The normal force applied in the column is one among several variables that influence exterior joints behavior. This variable was observed by many researchers (Parker & Bullman, 1997; Scott et al., 1999; Hwang & Lee, 1999; Bakir & Boduroglu, 2002; Hegger et al., 2003), however with divergences of opinions on its influence in the connection. So, this work aims to analyze the influence of the normal force in reinforcement concrete exterior joint behavior. In this way an extensive literature review is presented approaching experimental works and proposed theoretical models for the joint design (strut an ties). Inserting the research on the context, the influence of the normal force in exterior joints was done through experimental analysis of four connections with different levels of normal force, comparisons with the theoretical models presented and numerical simulation of the joint using finite elements method (FEM) packages at the software ABAQUS
4

Análise teórico-experimental da influência da força normal em nós de pórtico externos de concreto armado / Theoretical-experimental analysis of the influence of normal force on the exterior reinforced concrete joints behavior

Vladimir Guilherme Haach 30 June 2005 (has links)
Os nós de pórtico são locais de mudança de direção do eixo da estrutura, logo são regiões descontínuas, ou seja, as hipóteses de Bernoulli de deformações lineares ao longo da seção transversal não são válidas. Sendo assim os métodos convencionais de dimensionamento não se aplicam a esta região. Além disso, são regiões problemáticas também do ponto de vista construtivo, por apresentarem geralmente uma alta taxa de armadura em dimensões reduzidas. Diversas são as variáveis que influenciam o comportamento dos nós de pórtico externos, dentre elas está a força normal aplicada no pilar. Esta variável foi observada por diversos pesquisadores (Parker & Bullman, 1997; Scott et al., 1999; Hwang & Lee, 1999; Bakir & Boduroglu, 2002; Hegger et al., 2003), porém com grandes divergências de opiniões sobre sua influência na ligação. Desta forma, este trabalho visa analisar a influência da força normal no comportamento de nós de pórtico externos de concreto armado. Neste sentido é apresentada uma extensa pesquisa bibliográfica abordando trabalhos experimentais e modelos teóricos propostos para o dimensionamento dos nós (bielas e tirantes). Inserindo-se no contexto é analisada a influência da força normal nos nós de pórtico externos por meio da análise experimental de quatro ligações sujeitas a diferentes níveis de força normal, da comparação com os modelos teóricos apresentados e da simulação numérica do nó de pórtico com o aplicativo ABAQUS, utilizando como ferramenta básica o método dos elementos finitos (MEF) / The joints are points where the structures’ axes swerving, therefore they are discontinuous regions, it means, Bernoulli’s hypotheses of linear deformations over the section are not valid. Consequently the conventional methods of design are not applied to this region. Moreover, the joints are also problematic regions to build, for generally presenting one high reinforcement ratio in reduced geometricals dimensions. The normal force applied in the column is one among several variables that influence exterior joints behavior. This variable was observed by many researchers (Parker & Bullman, 1997; Scott et al., 1999; Hwang & Lee, 1999; Bakir & Boduroglu, 2002; Hegger et al., 2003), however with divergences of opinions on its influence in the connection. So, this work aims to analyze the influence of the normal force in reinforcement concrete exterior joint behavior. In this way an extensive literature review is presented approaching experimental works and proposed theoretical models for the joint design (strut an ties). Inserting the research on the context, the influence of the normal force in exterior joints was done through experimental analysis of four connections with different levels of normal force, comparisons with the theoretical models presented and numerical simulation of the joint using finite elements method (FEM) packages at the software ABAQUS
5

Výtah pro přepravu osob 675 kg / Passenger lift 675 kg

Špunar, Martin January 2011 (has links)
This master’s thesis deals with the design of the carrying frame of a lift cage with lift capacity of 675 kg. It’s main content is follow up strength analysis by Finite elements method (FEM). Thesis also contains the calculation of counterweight mass. Further is performed the calculation of the guide anchoring instituted for this steel structure and the strength analysis of the used guides according to norm ČSN EN 81-1. The thesis also includes the drawing of the carrying frame of the lift cage. Master’s thesis was carried out in co-operation with the LIFTMONT CZ company, Ltd.
6

Osobní výtah pro obytné budovy / Personal elevator for a residential building

Moravec, Josef January 2014 (has links)
Master’s thesis deals with application of new suspension means for personal elevator instead of conventional steel wire rope includes calculation of traction. Followed by assessment of passive resistance generated by guiding elevator on guide rails and caused by various locations of suspension and guiding (car guide rails). In the last part of thesis contains a strength analysis of car frame by Finite elements method (FEM) in programme NX I-deas.
7

Erweiterung der Verfahrensgrenzen des Flach-Clinchens / Enhancement of the process limitations of flat-clinching

Gerstmann, Thoralf 23 August 2016 (has links) (PDF)
Eines der am häufigsten in der Automobilindustrie eingesetzten mechanischen Fügeverfahren ist das Clinchen, auch Durchsetzfügen genannt. Hierbei werden zwei oder mehr sich überlappende Bleche lokal umgeformt, sodass eine form- und kraftschlüssige Verbindung mit matrizenseitiger Überhöhung entsteht. Eine Sonderform des Clinchens ist das Flach-Clinchen zur Herstellung einseitig ebener Clinch-Verbindungen. Mit dem Ziel, die Verfahrensgrenzen des konventionellen Flach-Clinchens zu erweitern, werden im Rahmen der vorliegenden Arbeit zwei neuartige Verfahrensvarianten des Flach-Clinchens entwickelt. Um die Verbindungsfestigkeit der Flach-Clinch-Verbindung zu erhöhen, wird ein zusätzliches Hilfsfügeelement in den Fügepunkt eingebracht. Dies bewirkt zum einen eine Vergrößerung des Hinterschnittes und daraus resultierend eine erhöhte Belastbarkeit gegenüber Kopfzugbeanspruchung. Zum anderen wird der Fügepunkt durch das zusätzliche Material stabilisiert und folglich die Belastbarkeit gegenüber Scherzugbeanspruchung verbessert. Die zweite Verfahrensvariante beinhaltet die Kombination aus Flach-Clinchen und Kleben zum sogenannten Flach-Clinchkleben. Hierbei dient die mechanische Verbindung hauptsächlich als Fixierhilfe bis zur vollständigen Aushärtung des Klebstoffs. Dies ermöglicht eine direkte Weiterverarbeitung des Bauteils nach dem Fügen und somit eine deutliche Verkürzung der Prozesszeiten. Die Entwicklung des Flach-Clinchens mit Hilfsfügeelement und des Flach-Clinchklebens erfolgt ausschließlich mittels numerischer Simulationen. Die hierbei gewonnenen Erkenntnisse werden anschließend experimentell verifiziert und die Verbindungsfestigkeiten der neuentwickelten Verfahrensvarianten bestimmt. / Clinching is one of the most common used mechanical joining processes in automotive industry. Here, two or more overlapping metal sheets are locally formed so that a form- and force-closed joint with diesided protrusion is established. A special type of clinching is the so-called flat-clinching for the production of one-sided planar joints. Within the framework of this thesis, two novel process variants of flat-clinching are developed for enhancing the process limitations of conventional flat-clinching. For increasing the joint strength, a complementary joining element is inserted into the joint. This causes an enlargement of the interlocking, leading to a higher resistance to cross tension loads. Also, the additional material stabilizes the joint and hence improves the resistance to shear load. The second process variant, adhesive flat-clinching, includes the combination of flat-clinching and adhesive bonding. The metal sheets are fixed by flat-clinching and the final joint strength is achieved after the complete curing of the adhesive. This enables a continuous processing of the component and therefore, the process time can be shortened. The development of flat-clinching using complementary joining elements and adhesive flat-clinching is exclusively carried out by using numerical simulation. The knowledge gained from the simulations is subsequently experimentally proven. Also, the joint strength of the novel process variants is experimentally determined.
8

Etude des phénomènes électromagnétiques dans les zones frontales des grandes machines synchrones : outils de tests sur le 125 MW / Study of electromagnetic phenomena in the end region of large turbo-generators : Testing tools for the 125 MW turbo-generator

Vogt, Gilles 06 December 2013 (has links)
Cette thèse s’inscrit dans le cadre des études des phénomènes électromagnétiques dansles régions frontales des grands turbo-générateurs. L’objectif de la thèse est d’estimer apriori le champ magnétique axial en fonction du point de fonctionnement afin d’éviterles possibles dégradations du circuit magnétique (dus aux points chauds et tensions entretôles, qui sont liés à la composante axiale du champ).Une maquette à échelle réelle a été spécialement conçue et réalisée dans le but d’améliorerla compréhension physique des phénomènes : les pertes, la pénétration du champ magnétiqueet les tensions entre tôles sont analysés.Les simulations par éléments finis sont ensuite utilisées : les avantages et inconvénientsseront discutés, ainsi qu’une comparaison critique des résultats par rapport aux mesuresexpérimentales sur la maquette. La région frontale d’un turbo-alternateur est aussi entièrementmodélisée.Enfin, un modèle simple du flux axial est développé. Ses coefficients sont déterminés àl’aide de simulations par éléments finis, mais il peut ensuite être utilisé en temps réel afind’estimer le flux axial correspondant à un point de fonctionnement quelconque. / This work aims to improve the knowledge of electromagnetic phenomena that occurin the end region of large turbo-generators. The goal of this work is to evaluate theaxial magnetic flux density with regard to the operating conditions (such as active orreactive power) in order to prevent potential deterioration of the stator. Indeed, the axialmagnetic field is known to induce hot points or voltages between laminations that maycause insulation breakdown and thus stator faults.An experimental apparatus in real scale has been designed and built. Its purpose is tostudy precisely the following phenomena: losses, axial magnetic flux density penetration,voltage across adjacent voltages.Finite element simulations (FEM) are also used: their advantages and drawbacks arediscussed, and the results are compared with the experimental measures. The wholeend-region of a turbo-generator is also simulated.Finally, a simple model of the axial magnetic flux is proposed. Its parameters are basedon the results of the FEM model, but it may be used in real time to evaluate the axialmagnetic flux density of any operating point.
9

Návrh testovacího stavu diferenciálu pro zástavbu v bezdozvukové komoře / Design of the Differential Test Rig for Testing in Anechoic Chamber

Ivanič, Michal January 2020 (has links)
The diploma thesis describes the design of a test stand for experimental determination of vibroacoustic parameters of a part of the powertrain system. Thesis contains a research part, describing the problems of the drive system, vibroacoustics, measuring devices and also the division and the description of test stands. At the same time, the reasons for choosing a closed loop test stand are explained. Thesis also includes the results of analytical calculations and numerical results of FEM methods performed using ANSYS software, as well as drawing documentation of individual parts.
10

Analýza šíření vibrací spojeným strukturálně akustickým prostorem / Vibration Propagation Analysis of Coupled Structure Acoustic Space

Kostelník, Jan January 2011 (has links)
The aim of this Master’s thesis Vibration Propagation Analysis of Coupled Structure Acoustic Space is to analyze vibration propagation in combustion engine, from combustion space through solid structure to fluid surroundings. Then analyze the noise increase as pressure changing in fluid space around the solid structure. There was made a analyze of single piston engine in different frequency and piston location. A simulation of distribution of a pressure waves was made in an ANSYS application.

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