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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.
121

[pt] ESTUDO DOS FATORES DE SEGURANÇA EM ANÁLISES POR EQUILÍBRIO LIMITE EM MODELOS BI E TRIDIMENSIONAIS / [en] STUDY OF SAFETY FACTORS IN LIMIT EQUILIBRIUM ANALYSIS IN TWO AND THREE-DIMENSIONAL MODELS

PAULA TAVARES PEDROSA 09 August 2022 (has links)
[pt] Análises de estabilidade bidimensionais são predominantemente utilizadas na prática geotécnica, tendo em vista a praticidade e os resultados, em sua maioria, mais conservadores, tornando as análises tridimensionais ainda pouco disseminadas. Por este motivo, o presente trabalho possui como objetivo a comparação entre os fatores de segurança encontrados em análises 2D e 3D e também em retroanálises, buscando verificar o comportamento de taludes nesses dois tipos de análise e comparar com o esperado no campo para cada caso. Sendo assim, o presente estudo se dividiu entre estudos preliminares em taludes hipotéticos, a fim de validar as análises realizadas no software computacional 2D e 3D, e em um estudo de caso para a realização de retroanálises em casos bi e tridimensionais de um talude rompido. As análises e retroanálises foram realizadas no programa computacional SVSlope, da SoilVision Systems Ltd., utilizando o método de equilíbrio limite de Morgenstern e Price (1965) e adotando o critério de ruptura de Mohr-Coulomb para quantificação dos parâmetros de resistência dos solos. Os casos hipotéticos consideraram taludes homogêneos, de solos arenosos, em três condições de geometria: talude infinito, talude não infinito com topografia constante e talude não infinito com altura variável, impondo uma variação de topografia. Já o estudo de caso foi realizado em uma encosta que sofreu movimentações, estando localizada na Rodovia Rio-Santos, município de Mangaratiba, no Rio de Janeiro. Os resultados das análises mostraram que, para os casos estudados, a análise de estabilidade 2D apresenta resultados compatíveis com a condição 3D, ainda que conservadores. No entanto, em projetos onde seja necessária a realização de retroanálises, mostrou-se ser mais prudente a utilização de análises 3D, uma vez que esta resulta em parâmetros de resistência ao cisalhamento (c e ângulo de atrito interno do solo) menores, logo, mais conservadores. / [en] Two-dimensional stability analyzes are predominantly used in geotechnical practice, in view of the practicality and results, most of them, more conservative, making three-dimensional analysis still little disseminated. For this reason, the present work aims to compare the safety factors found in 2D and 3D analysis and back analysis, seeking to verify the behavior of the slope in these two types of analysis and to compare with what is expected in reality for each case. Thus, the present study was divided between preliminary studies on hypothetical slopes, in order to validate the analysis performed in 2D and 3D computational software, and in a case study to perform back analysis in two and three-dimensional cases of a broken slope. The analysis and back analyses were performed in the computer program SVSlope, from SoilVision Systems Ltd., using the limit equilibrium method of Morgenstern and Price (1965) and adopting the Mohr-Coulomb rupture criterion to quantify the soil resistance parameters. The hypothetical cases considered homogeneous slopes, with sandy soils, in three geometry conditions: infinite slope, non-infinite slope with constant topography and non-infinite slope with variable height, imposing a variable topography. The case study, on the other hand, was carried out on a slope that suffered movement, being located on the Rio-Santos Highway, in the municipality of Mangaratiba, in Rio de Janeiro. The results of the analysis showed that, for the cases studied, the 2D stability analysis presents reasonable results and is compatible with the 3D condition, although conservative. However, in projects where back analysis is necessary, the use of 3D analysis proved to be more prudent, since this results in lower shear strength parameters (c and internal friction angle of the ground), therefore, more conservative.
122

Designing for Engagement: Using indirect manipulation to support form exploration in 3D modeling

Serim, Baris January 2012 (has links)
This thesis aims to study the design possibilities for supporting explorative form-finding in 3D modeling applications. For today’s many design professions, 3D forms are achieved partly in engagement with digital environments. Use of software has far exceeded final idea execution, extending to the early phases of design work in which the outcome is not predetermined. This insight led designers of interactive systems support sketching and ideating activities by reducing the risk of experimentation and cognitive effort demanded from user. Yet, there has been less emphasis on traditional design and craft practice that acknowledges engagement with materials and effort spent on work as an integral part of creative process.The notion of exploration in the scope of this thesis attempts to incorporate such aspects. Relevant literature about workshop practice in design and craft has been reviewed, as well as examples of CAD technologies that aid designers. In this light, HCI perspectives on the design of creativity support tools and games have been discussed. The thesis work aimed to concretize this background by building a design strategy and an interactive artifact. A 3D form-finding application concept using objects in modeling space to indirectly manipulate geometry, “kfields”, has been developed and evaluated with users at various stages. The thesis concludes by reflecting on the findings of different design stages and proposing further directions for design.
123

Art en réseaux : la structure des réseaux comme une nouvelle matrice pour la production des œuvres artistiques / Art & Networks : networks structure as a new matrix for the production of artworks

Souliotou, Anastasia Zoé 19 May 2015 (has links)
La problématique de ce doctorat est : comment la structure des réseaux constitue une nouvelle matrice pour la production d’oeuvres artistiques. Pour répondre à cette question, nous commencerons en étudiant l’évolution de la notion de « réseau » de l’antiquité jusqu’à aujourd’hui ; les théories des réseaux concernant leur structure et/ou leur dynamique. Ensuite nous présenterons les applications –de la notion ou des théories de réseaux– tant dans les sciences que dans l’art. Nous listerons et nous analyserons huit types de réseaux et puis nous mentionnerons des oeuvres artistiques qui ont été inspirées par ces types de réseaux et/ou qui utilisent certains (types de) réseaux comme matrice pour leur création. Nous proposerons le projet Lignes Imaginaires, un modèle 3D qui se fonde sur la conception d’un métro de lignes imaginaires, voire de lignes dynamiques et/ou paradoxales qui sont en mouvement, apparaissent/disparaissent, créent de l’infrastructure supplémentaire. L’analyse du métro Lignes Imaginaires dévoile l'importance de la géographie et de la spatialité des réseaux, tandis que leur représentation graphique topologique reste insuffisante pour la représentation précise et pour la compréhension de leur structure (paradoxale). En outre, l’innovation du métro Lignes Imaginaires est que son infrastructure est dynamique et auto-organisée, contrairement aux métros traditionnels où les lignes et leurs itinéraires sont fixes. L’objectif du projet artistique Lignes Imaginaires est de visualiser un concept en créant un métro hors du commun qui pourrait aussi proposer des formes alternatives des réseaux de transports dans le contexte urbain. / This thesis examines and shows ways in which the structure of networks can provide a new matrix for the production of artworks. In order to answer this question we start by studying: the evolution of the term ‘network’ from the ancient times up to nowadays; the theories that refer to network structure or network dynamics. Then we present the applications of these theories into both art and science. We list and analyze eight different types of networks and then we feature artworks which have been inspired by these network types or have used the network structure of a certain type as a matrix for art making. We propose the Imaginary Lines project, a three-dimensional network model which is based on the concept of a metro composed of imaginary lines. More precisely Imaginary Lines metro network encompasses seven paradoxical lines which move, (dis)appear and produce supplementary infrastructure. The Imaginary Lines metro unveils the importance of geography and spatiality, in contrast with topological network graphic representations, which remain insufficient, in terms of utmost accuracy in representation and comprehension of network structure. Additionally, the Imaginary Lines network innovation lays in its infrastructure dynamics as well as in its self-organisation. The objective of the Imaginary Lines artistic project is to visualise a concept by creating an unusual metro, which goes beyond traditional fixed-route transport networks and can support alternative forms of urban transport development.
124

Proposta de metodologia de avaliação para salas de coordenação de projetos em BIM. / Proposal evaluation methodology for BIM design coordination rooms.

Addor, Míriam Roux Azevedo 30 September 2015 (has links)
A Modelagem da Informação da Construção (Building Information Modeling - BIM) é um novo processo para produzir uma edificação e que pode englobar todo o seu ciclo de vida. Pressupõe a construção de um modelo tridimensional contemplando-se as informações dos objetos a serem construídos. Pela grande amplitude em que este processo pode atuar, ele pode causar muitos impactos em toda a cadeia produtiva e, consequentemente, muitas formas atuais de trabalho deverão ser revistas ou alteradas. Entre estas, a atividade de coordenação de projetos. Este trabalho tem como objetivo o desenvolvimento de uma metodologia de avaliação de salas de coordenação de projetos em BIM e está contextualizado nos usuários do setor imobiliário que utilizam este processo em seus projetos. Ao se coordenar projetos em BIM, são requeridas mídias diferentes daquelas utilizadas quando a análise é baseada em papel. Surgem novas necessidades aos participantes da reunião de coordenação como visualizar, navegar ou verificar um modelo 3D, fazer croquis digitais, e outras atividades que devem tornar a reunião presencial produtiva, com o objetivo de resolver os problemas dos projetos. Neste trabalho são propostos critérios e métricas para avaliação da qualidade de leiautes de salas de coordenação a serem utilizadas no processo BIM (BIM Rooms). Para validação dos resultados, foram analisados e avaliados 14 leiautes diferentes para uma mesma sala em relação às métricas e critérios propostos. Com a finalidade de estabelecer qual a relação de importância entre todos os 10 critérios propostos para atendimento às necessidades dos participantes de reuniões BIM, foi aplicado o método AHP de decisão multicritério baseado na análise de comparações em pares. Os resultados permitiram determinar os melhores leiautes para uma sala equipada com 2 projetores de curta distância. Os critérios e métricas apresentados, bem como a metodologia para medi-los, são úteis para a avaliação de outras salas e leiautes para atender aos usuários de salas de reuniões de projetos baseados em BIM. / Building Information Modeling (BIM) is a new process to produce a building that may include its entire lifecycle. It requires the construction of a three-dimensional model contemplating the information of the objects to be built. Due to the great extent to which this process can serve, it can cause many impacts throughout the production chain and, therefore, many current forms of work should be reviewed or changed. Among these, is the design coordination task. This work aims to develop a methodology for evaluating BIM coordination rooms contextualized in real state users using this process in their projects. When coordinating projects using BIM, different media are required from those used when the analysis is paper-based. New meeting participants\' needs surface like visualizing, browsing or checking a 3D model, making digital sketches, and other activities that make face-to-face meetings productive, in order to solve project problems. In this work, criteria and metrics for evaluating the quality of layouts of BIM coordination rooms are proposed. To validate the results, fourteen different layouts for the same room were analyzed and evaluated regarding proposed metrics and criteria. In order to establish the relative importance among all the ten proposed criteria, the AHP method of multi-criteria decision based on pair comparisons analysis was applied. The results determined the best layouts for a room equipped with two interactive projectors. The criteria and metrics presented, as well as the methodology to measure them, are useful for the evaluation of other rooms and layouts to serve meeting room users based on BIM.
125

Vägmodellering baserad på laserskanning för virtuella fordonssimuleringar / Road modeling based on laser scanning for virtual vehicle simulations

Larsson, Oskar, Hallberg, Jacob January 2019 (has links)
För att kunna konkurrera inom dagens fordonsindustri krävs effektiv produktutveckling. Det är under designprocessen som det finns störst möjlighet att påverka slutprodukten till det bättre. Ett sätt att åstadkomma effektivare produktutveckling är att tillämpa ny teknik. För att generera digitaliserade vägmodeller som används i simuleringar kan laserskanning appliceras. I dessa simuleringar kan fordonen testköras virtuellt och därigenom förkorta dimensioneringsprocessen. Laserskanning av kuperad terräng är komplex och därför saknas det underlag av kuperade testbanor i simuleringar. Denna studie syftar till att presentera olika laserskanningstekniker samt att utöka underlaget för virtuella simuleringar inom dimensioneringsprocessen av dumprar. Målet med arbetet är att skapa virtuella vägsektioner som kan användas i simuleringsmodeller.  Tre huvudtekniker inom laserskanning presenteras i teorikapitlet. Vidare har terrest laserskanning utförts på Volvos testbana i Målajord och med skanningsdata som underlag har en vägmodell som kan användas i fordonssimuleringar skapats i Matlab. Vägmodellen som skapats representerar väl den verkliga körbanan, vilket indikerar att terrest laserskanning är en väl fungerande metod för detta ändamål. / Product development is necessary to compete in today´s vehicle industry. During the design process the largest possibility to affect the end product to the better exists. One way to achieve product development is to apply new technology. Through application of terrestrial laser scanning digitalized road models can be achieved and be used in simulations. In these simulations, vehicles can virtually do a trial run and thereby shorten the dimensionprocess. Laser scanning of hilly terrain is complex and therefore groundwork of hilly roadways in simulations is missing.  This study refers to present different types of laser scanning methods and expand the groundwork for virtual simulations in the dimensionprocess of dumpers. The vision is to create virtual roadways which can be used in simulation models. Three main techniques of laser scanning are presented in the theory chapter. Further on terrestrial laser scanning has been used on Volvos test track in Målajord and with this scanning data as groundwork a road model, which can be used in vehicle simulations, has been created in Matlab. The road model is well representing the real roadway, which indicates that terrestrial laser scanning is a well working method for this purpose.
126

Modélisation et simulation 3D de la rupture des polymères amorphes / Modelling and numerical study of 3D effect on glassy polymer fracture

Guo, Shu 08 July 2013 (has links)
Le sujet concerne l’influence des effets tridimensionnelles sur les champs de déformation et de contrainte au voisinage d’une éprouvette chargée en mode I. La loi de comportement caractéristique des polymères amorphes avec un seuil d’écoulement viscoplastique suivi d’un adoucissement et d’un durcissement à mesure que la déformation augmente est prise en compte. La loi est implantée dans une UMAT abaqus. Les champs au voisinage de l’entaille sont analysés et les résultats 3D comparés à ceux correspondant à un calcul 2D sous l’hypothèse de déformation plane. L’influence de l’épaisseur de l’échantillon est étudiée et nous montrons qu’au-delà d’un rapport épaisseur t sur rayon d’entaille rt, t/rt>20, les champs de déformation plastique sont qualitativement similaires entre les calculs 3D et 2D. En revanche, nous montrons que la répartition des contraintes et notamment celle de la contrainte moyenne est sur-estimée avec un calcul 2D en comparaison à une simulation 3D. Nous prenons en compte par la suite la rupture par craquelage, modélisée avec un modèle cohésif. Une étude paramétrique est menée afin de définir une procédure d’identification des paramètres caractéristiques du modèle cohésif. Par ailleurs les simulations montrent qu’au-delà d’un rapport t/rt supérieur à 20, une ténacité minimum peut être estimée : ceci constitue un résultat important pour la détermination expérimentale de la ténacité des polymères ductiles. / We investigate 3D effect of crack tip palsticity and the influence of the thickness on 3D glassy polymer fracture. The characteristuc constitutive law with a viscoplastic yield stress followed by softening and progressive hardening is accoutne for and implemented in a UMAt routine, in abaqus. The crack tip fields are investigated and 2D plasne strain versus 3D calculations compared. Qualitatively, the palstic distribution are comparableas soon as the ratio thickness over crack tip radius is larger than 20. However, the 2D calculations over estimate the stress distribution compared to the 3D cases. We have accounted for failure by crazing that is described with a cohesive models. A parametric study sheds light on the methodology to use for the calibration of the cohesive parameters. The simulations show that for a ratio thickness over craci tip radius larger than 20, a minimum tuoghness can be observed. This results has implication on the definition of a thickness larger enough experimentally.
127

Finite Element Modeling of Extensor Carpi Radialis Longus and Brevis: Computation of Architectural Parameters and Physiological Cross Sectional Area as Whole Muscles and Regions

Ravichandiran, Kajeandra 15 February 2010 (has links)
Physiological cross sectional area (PCSA) is used to compare force-producing capabilities of skeletal muscles. PCSA has been defined as the summation of the cross sectional area of the fiber bundles composing the muscle. As PCSA cannot be measured directly from a specimen, a formula requiring averaged muscle architectural parameters has traditionally been used. The purpose of this study was to develop a finite element method (FEM) to calculate PCSA of extensor carpi radialis longus (ECRL) and brevis (ECRB) directly from digitized fiber bundle data obtained throughout the volume of the muscle and to compare the PCSAs calculated using the FEM and formula methods. Differences were found between the FEM and formula method for both muscles. The FEM provides an approach that takes into account architectural variances while minimizing the need for averaged architectural parameters.
128

Finite Element Modeling of Extensor Carpi Radialis Longus and Brevis: Computation of Architectural Parameters and Physiological Cross Sectional Area as Whole Muscles and Regions

Ravichandiran, Kajeandra 15 February 2010 (has links)
Physiological cross sectional area (PCSA) is used to compare force-producing capabilities of skeletal muscles. PCSA has been defined as the summation of the cross sectional area of the fiber bundles composing the muscle. As PCSA cannot be measured directly from a specimen, a formula requiring averaged muscle architectural parameters has traditionally been used. The purpose of this study was to develop a finite element method (FEM) to calculate PCSA of extensor carpi radialis longus (ECRL) and brevis (ECRB) directly from digitized fiber bundle data obtained throughout the volume of the muscle and to compare the PCSAs calculated using the FEM and formula methods. Differences were found between the FEM and formula method for both muscles. The FEM provides an approach that takes into account architectural variances while minimizing the need for averaged architectural parameters.
129

Proposta de metodologia de avaliação para salas de coordenação de projetos em BIM. / Proposal evaluation methodology for BIM design coordination rooms.

Míriam Roux Azevedo Addor 30 September 2015 (has links)
A Modelagem da Informação da Construção (Building Information Modeling - BIM) é um novo processo para produzir uma edificação e que pode englobar todo o seu ciclo de vida. Pressupõe a construção de um modelo tridimensional contemplando-se as informações dos objetos a serem construídos. Pela grande amplitude em que este processo pode atuar, ele pode causar muitos impactos em toda a cadeia produtiva e, consequentemente, muitas formas atuais de trabalho deverão ser revistas ou alteradas. Entre estas, a atividade de coordenação de projetos. Este trabalho tem como objetivo o desenvolvimento de uma metodologia de avaliação de salas de coordenação de projetos em BIM e está contextualizado nos usuários do setor imobiliário que utilizam este processo em seus projetos. Ao se coordenar projetos em BIM, são requeridas mídias diferentes daquelas utilizadas quando a análise é baseada em papel. Surgem novas necessidades aos participantes da reunião de coordenação como visualizar, navegar ou verificar um modelo 3D, fazer croquis digitais, e outras atividades que devem tornar a reunião presencial produtiva, com o objetivo de resolver os problemas dos projetos. Neste trabalho são propostos critérios e métricas para avaliação da qualidade de leiautes de salas de coordenação a serem utilizadas no processo BIM (BIM Rooms). Para validação dos resultados, foram analisados e avaliados 14 leiautes diferentes para uma mesma sala em relação às métricas e critérios propostos. Com a finalidade de estabelecer qual a relação de importância entre todos os 10 critérios propostos para atendimento às necessidades dos participantes de reuniões BIM, foi aplicado o método AHP de decisão multicritério baseado na análise de comparações em pares. Os resultados permitiram determinar os melhores leiautes para uma sala equipada com 2 projetores de curta distância. Os critérios e métricas apresentados, bem como a metodologia para medi-los, são úteis para a avaliação de outras salas e leiautes para atender aos usuários de salas de reuniões de projetos baseados em BIM. / Building Information Modeling (BIM) is a new process to produce a building that may include its entire lifecycle. It requires the construction of a three-dimensional model contemplating the information of the objects to be built. Due to the great extent to which this process can serve, it can cause many impacts throughout the production chain and, therefore, many current forms of work should be reviewed or changed. Among these, is the design coordination task. This work aims to develop a methodology for evaluating BIM coordination rooms contextualized in real state users using this process in their projects. When coordinating projects using BIM, different media are required from those used when the analysis is paper-based. New meeting participants\' needs surface like visualizing, browsing or checking a 3D model, making digital sketches, and other activities that make face-to-face meetings productive, in order to solve project problems. In this work, criteria and metrics for evaluating the quality of layouts of BIM coordination rooms are proposed. To validate the results, fourteen different layouts for the same room were analyzed and evaluated regarding proposed metrics and criteria. In order to establish the relative importance among all the ten proposed criteria, the AHP method of multi-criteria decision based on pair comparisons analysis was applied. The results determined the best layouts for a room equipped with two interactive projectors. The criteria and metrics presented, as well as the methodology to measure them, are useful for the evaluation of other rooms and layouts to serve meeting room users based on BIM.
130

Modelování proudění v bezpečnostním přelivu vodního díla Letovice / Modelling of Flow over Spillway of the Letovice Dam

Škrach, Mikuláš January 2019 (has links)
The thesis is concerned on numerical modeling of a scheduled spillway on water structure Letovice. The goal of the thesis is to verify hydraulic calculation using numerical modeling and to verify the capacity of the spillway. The spacial model was created in SketchUp program and the numerical modeling was implemented in Flow-3D program. The reason to recalculate the spillway is its reconstruction and extension in order to make high a capacity of it in the final project of Letovice water structure whole reconstruction.

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