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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

Understand Your Design!

Brandt, Andreas 25 June 2013 (has links)
Der Vortrag demonstriert am Beispiel eines Designraumes die Kombination aus einem FE-Werkzeug mit parametrischen Untersuchungen.
102

Developing an Architecture Framework for Cloud-Based, Multi-User, Finite Element Pre-Processing

Briggs, Jared Calvin 14 November 2013 (has links) (PDF)
This research proposes an architecture for a cloud-based, multi-user FEA pre-processing system, where multiple engineers can access and operate on the same model in a parallel environment. A prototype is discussed and tested, the results of which show that a multi-user preprocessor, where all computing is done on a central server that is hosted on a high performance system, provides significant benefits to the analysis team. These benefits include a shortened preprocessing time, and potentially higher-quality models.
103

Behavioral Analysis of Volvo Cars Instrument Panel During Airbag Deployment

Nazari, Amir, Nourozi, Behrouz January 2016 (has links)
Airbags are a passive safety technology, required to function with zero failure rate. Advances in Computer Aided Engineering have allowed vehicle manufacturers to predict material and system behavior in the event of a crash. The sudden and rapid nature of a vehicle frontal crash, together with strict requirements put on safety make this a sensitive task. This thesis focuses on the front passenger airbag deployment and the instrument panel’s response. Various airbag modelling techniques are studied and presented in this document. This work is part of a larger-scale attempt to model a generic-sled that is physically representative of a real vehicle. Various component tests are to be performed in the sled environment, as opposed to a real vehicle, to save costs. Various modules are added to the sled once their behavior is verified by testing and in simulations. Software are advanced enough to identify location and magnitude of stress concentrations that develop during crash. LS-DYNA is used for explicit finite element simulations of the instrument panel (IP) in question with different airbag models. Verification has been achieved by design of experiment (DOE); with tests conducted to capture both the movements of the airbag housing and IP movements in response. These movements are broken down in various phases, facilitating implementation in the sled environment. Simplifications are made both to the computer models as well as the physical testing environment. The effects of these simplifications are quantified and discussed. Theoretical background is provided where fit while assumptions are justified wherever made. DYNAmore recommendations regarding costeffective calculations as well as result verification are followed. The obtained results show that the FE models replicate the real event with acceptable precision. The findings in this work can, by minor tweaks, be implemented on other IP models in the Volvo Cars range, leading to cost-saving solutions. This thesis provides the necessary information for sled implementations as well as future improvement suggestions. / Krockkudde är en s.k. passiv säkerhetsteknik som krävs att fungera felfritt. Framsteg inom Computer Aided Engineering har tillåtit biltillverkare att förutsäga material och systembeteende i samband med krock. Den plötsliga karaktären av krock, tillsammans med höga säkerhetskrav, gör detta till en känslig uppgift. Denna avhandling fokuserar på passagerarsidans krockkudde och instrumentbrädans (IP) respons under uppblåsning. Olika metoder för modellering av krockkuddar har studerats och presenteras i detta dokument. Arbetet är en del av en större skala försök att modellera en generisk-släde som är fysiskt representativ av en riktig bil; där olika komponent-tester skall utföras för att minska kostnader. När olika modulers beteende verifieras läggs de till släden. Denna verifiering sker genom finita element (FE) simuleringar så väl som fysiska tester. FE mjukvara är idag tillräckligt avancerad för att identifiera samt visualisera spänningskoncentrationer som uppstår i en konstruktion vid krock. LS-DYNA används i detta arbete för explicita FE simuleringar av en Volvo XC90 IP, lastad med olika krockkudde-modeller. Modell verifiering har uppnåtts genom försöksplanering (DOE); med tester utförda för att fånga rörelser av IP så väl som krockkudde-behållaren. Dessa rörelser är sedan uppdelade i olika faser för enklare genomförande i släde miljön. Förenklingar och antaganden görs både till FE modeller och fysiska testmiljön. Effekter av dessa har kvantifierats och relevant teoretisk bakgrund har inkluderats. Dokumentet innehåller även diskussion kring val av mätutrustning samt förbättringsförslag för fortsatt arbete. DYNAmore rekommendationer gällande kostnadseffektiva beräkningar och verifiering av simulerings-resultat har följts. Under arbetet visade sig att FE modellerna kan återskapa händelsen med hög noggrannhet; dessa trotts svårigheter i modellering av plast material. Möjligtvis kan man, genom mindre modifieringar, relatera slutsatserna i detta arbete till olika IP modeller i företagets produktkatalog vilket förmodligen leder till ytterligare kostnadsbesparingar. Denna avhandling ger den information som behövs för genomföranden i den generiska miljön.
104

Development of hybrid lifecycle cost estimating tool (hlcet) for manufacturing influenced design tradeoff

Sirirojvisuth, Apinut 21 May 2012 (has links)
In complex aerospace system design, making effective decision requires knowledge from all disciplines, both product and process perspectives. Manufacturing knowledge integration is most valuable during the early phase of the design since designers have more freedom, and design changes are relatively inexpensive. Yet, there is still lack of structured methodology that will allow feedback from the process perspective to show the impact of the design decisions in a quantifiable manner. The major metrics in the design decision as far as process is concerned are cost, time, and manufacturability. To incorporate these considerations in the decision making process without sacrificing agility and flexibility required during conceptual and preliminary design phases, a new set of software analysis tools are proposed. To demonstrate the applicability of this concept, a Hybrid Lifecycle Cost Estimating Tool (HLCET) is developed, and integrated to existing design methodology, Integrated Product and Process Development (IPPD). The ModelCenter suite is used to develop software architecture that seamlessly integrate between product and process analysis tools, and enable knowledge transfer between design phases. HLCET integrates high fidelity estimating techniques like process-based and activity-based into a hierarchical lifecycle cost model to increase the sensitivities of the top-down LCC model to changes or alternatives evaluated at the part or component level where tradeoff is required. Instead of applying arbitrary complexity factor to existing CERs to account for difference material or process selection, high fidelity tool can be used to related product and process parameters specific to the design to generate new result that can then be used to update top-level cost result. This new approach to lifecycle cost estimation allows for a tailored study of individual processes typically required for new and innovative designs. An example of a hypothetical aircraft wing redesign demonstrates the utility of HLCET.
105

Planning stability in material requirements planning systems /

Heisig, Gerald. January 1900 (has links)
Thesis (doctoral)--Universität, Magdeburg. / Includes bibliographical references.
106

Moving targets: Political theatre in a post-political age

Reynolds, Ryan Michael January 2006 (has links)
This thesis gauges the contemporary landscape of political theatre at a time in which everything, and consequently nothing, is political. That is, almost all theatres today proclaim a politics, and yet there is widespread resignation regarding the inevitability of capitalism. This thesis proposes a theory of political action via the theatre: radical theatre today must employ a strategy of "moving targets". Theatrical actions must be adaptable and mobile to seek out the moving targets of capital and track down target audiences as they move through public space. In addition, political theatre must become a moving target to avoid amalgamation into the capitalist system of exchange. I approached this topic through four case studies. Two of the case studies, Reverend Billy's Church of Stop Shopping and the Critical Art Ensemble, are based in the United States. I studied their work via materials - books, essays, videos, websites, interviews, and more - but not in person. The other two case studies are lifted from my own experience with the Christchurch Free Theatre: an original production of Christmas Shopping and a devised production of Karl Kraus' play The Last Days of Mankind. These latter two case studies served as laboratory experiments through which I was able to test ideas and problematics of political theatre that arose through my research. These case studies led to the determination that creating aesthetic experiences and actions - as opposed to having explicitly political content - can be a strategy or foundation for a radical political theatre that resists, undermines, and at times transcends the seeming inevitability of consumer capitalism. In an age in which any political intervention is seen as senseless disruption, a form of pointless violence, this theatre has adopted the strategies of terrorist actions to have a disruptive effect without positing a specific alternative social structure.
107

Idéalisation d'assemblages CAO pour l'analyse EF de structures / Idealization of CAD assemblies for FE structural analyses

Boussuge, Flavien 08 July 2014 (has links)
Les entreprises aéronautiques ont un besoin continu de générer de grands et complexes modèles de simulation, en particulier pour simuler le comportement structurel de sous-systèmes de leurs produits. Actuellement, le pré-traitement des modèles de Conception Assistée par Ordinateur (CAO) issus des maquettes numériques de ces sous-systèmes en Modèles Eléments Finis (MEF), est une tâche qui demande de longues heures de travail de la part des ingénieurs de simulation, surtout lorsque des idéalisations géométriques sont nécessaires. L'objectif de ce travail de thèse consiste à définir les principes et les opérateurs constituant la chaîne numérique qui permettra, à partir de maquettes numériques complexes, de produire des géométries directement utilisables pour la génération de maillages éléments finis d'une simulation mécanique. A partir d'une maquette numérique enrichie d'information sur les interfaces géométriques entre composants et d'information sur les propriétés fonctionnelles de l'assemblage, l'approche proposée dans ce manuscrit est d'ajouter un niveau supplémentaire d'enrichissement en fournissant une représentation structurelle de haut niveau de la forme des composants CAO. Le principe de cet enrichissement est d'extraire un graphe de construction de modèles CAO B-Rep de sorte que les processus de génération de forme correspondants fournissent des primitives volumiques directement adaptées à un processus d'idéalisation. Ces primitives constituent la base d'une analyse morphologique qui identifie dans les formes des composants à la fois des sous-domaines candidats à l'idéalisation mais également les interfaces géométriques qui leurs sont associées. Ainsi, les modèles de composants et leurs représentations géométriques sont structurés. Ils sont intégrés dans la maquette numérique enrichie qui est ainsi contextualisée pour la simulation par EF. De cette maquette numérique enrichie, les objectifs de simulation peuvent être utilisés pour spécifier les opérateurs géométriques adaptant les composants et leurs interfaces lors de processus automatiques de préparation d'assemblages. Ainsi, un nouveau procédé d'idéalisation de composant unitaire est proposé. Il bénéficie de l'analyse morphologique faite sur le composant lui fournissant une décomposition en sous-domaines idéalisables et en interfaces. Cette décomposition est utilisée pour générer les modèles idéalisés de ces sous-domaines et les connecter à partir de l'analyse de leurs interfaces, ce qui conduit à l'idéalisation complète du composant. Enfin, le processus d'idéalisation est étendu au niveau de l'assemblage et évolue vers une méthodologie de pré-traitement automatique de maquettes numériques. Cette méthodologie vise à exploiter l'information fonctionnelle de l'assemblage et les informations morphologiques des composants afin de transformer à la fois des groupes de composants associés à une même fonction ainsi que de traiter les transformations d'idéalisation de l'assemblage. Pour démontrer la validité de la méthodologie, des opérateurs géométriques sont développés et testés sur des cas d'application industriels. / Aeronautical companies face a significant increase in complexity and size of simulation models especially at the level of assemblies, sub-systems of their complex products. Pre-processing of Computer Aided Design (CAD) models derived from the digital representation of sub-systems, i.e., Digital Mock-Ups (DMUs), into Finite Elements Analysis (FEA) models requires usually many tedious manual tasks of model preparation and shape transformations, in particular when idealizations of components or assemblies have to be produced. Therefore, the purpose of this thesis is to make a contribution to the robust automation of the time-consuming sequences of assembly preparation processes. Starting from an enriched DMU with geometrical interfaces between components and functional properties, the proposed approach takes DMU enrichment to the next level by structuring components' shapes. This approach extracts a construction graph from B-Rep CAD models so that the corresponding generative processes provide meaningful volume primitives for idealization application. These primitives form the basis of a morphological analysis which identifies the sub-domains for idealization in the components' shapes and their associated geometric interfaces. Subsequently, models of components as well as their geometric representation get structured in an enriched DMU which is contextualized for FEA application. Based on this enriched DMU, simulation objectives can be used to specify geometric operators that can be robustly applied to automate components and interfaces shape transformations during an assembly preparation process. A new idealization process of standalone components is proposed while benefiting from the decomposition into sub-domains and their geometric interfaces provided by the morphological analysis of the component. Interfaces between sub-domains are evaluated to robustly process the connections between the idealized sub-domains leading to the complete idealization of the component. Finally, the scope of the idealization process is extended to shape transformations at the assembly level and evolves toward a methodology of assembly pre-processing. This methodology aims at exploiting the functional information of the assembly and interfaces between components to perform transformations of groups of components and assembly idealizations. In order to prove the applicability of the proposed methodology, corresponding operators are developed and successfully tested on industrial use-cases.
108

Uso de wavelets para a melhoria de desempenho de simulações numéricas usando carregamentos de pistas na indústria automotiva

Andrade, Gustavo Souza January 2009 (has links)
93f. / Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-04-10T19:28:26Z No. of bitstreams: 1 Dissertacao-Andrade2009.pdf: 2855290 bytes, checksum: 594e02d722d8945462d506683b9443b0 (MD5) / Approved for entry into archive by Rodrigo Meirelles(rodrigomei@ufba.br) on 2013-06-06T18:56:16Z (GMT) No. of bitstreams: 1 Dissertacao-Andrade2009.pdf: 2855290 bytes, checksum: 594e02d722d8945462d506683b9443b0 (MD5) / Made available in DSpace on 2013-06-06T18:56:16Z (GMT). No. of bitstreams: 1 Dissertacao-Andrade2009.pdf: 2855290 bytes, checksum: 594e02d722d8945462d506683b9443b0 (MD5) Previous issue date: 2009 / Wavelets são poderosas ferramentas matemáticas que, entre outras aplicações, visam melhorar a decomposição tempo-freqüência de sinais, avaliando-os em diferentes escalas, em uma abordagem multi-resolução que permite a analise dos diferentes aspectos da informação contida no respectivo sinal. Apesar de ser uma ferramenta relativamente nova, ela vem sendo aplicada em várias áreas do conhecimento humano, e é muito popular no processamento de sinais, particularmente na área compressão de sinais, tais como imagens, vídeo e áudio em computadores. A compressão de sinais está associada com a perda de informação, mas que pode ser aceitável para o usuário final. Com base em aplicações anteriores bem sucedidas e o compromisso com a qualidade dos resultados, este trabalho avalia a utilização da Transformada Wavelet Discreta (DWT), como uma técnica de compressão para reduzir a quantidade de dados coletados em sinais de carregamentos de pista (load history), que são utilizados por equipes de engenharia de durabilidade na indústria automotiva. Resultados preliminares mostram que com a utilização da DWT na compressão desses sinais, é possível reduzir o esforço computacional, tempo de processamento, espaço de armazenamento e tráfego de dados entre os computadores, melhorando o processo numérico computacional (CAE) de determinação de tensões, deformações e conseqüentemente da vida em relação a fadiga, ainda mantendo os parâmetros desejados de qualidade. / Salvador
109

Automação e integração CAD/CAE no projeto de estruturas metalicas, utilizando perfis tubulares / Automation and integration CAD/CAE on the design of steel structures, using hollow sections

Souza, Mauricio Guilherme Quilez 28 August 2006 (has links)
Orientador: João Alberto Venegas Requena / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-09T16:24:16Z (GMT). No. of bitstreams: 1 Souza_MauricioGuilhermeQuilez_M.pdf: 5444391 bytes, checksum: f64376df9364d46cfcb18e6ba06eff3a (MD5) Previous issue date: 2006 / Resumo: Este trabalho tem como objetivo o desenvolvimento de códigos de computador que têm a finalidade de automatizar as etapas principais de um projeto de estruturas metálicas através das linguagens AutoLISP e Delphi5. Os projetos de estruturas metálicas em estudo são os de coberturas com treliças planas constituídas de barras com perfis tubulares laminados sem costuras e seus contraventamentos. Estes perfis tubulares, ainda pouco utilizados em estruturas planas no Brasil, vêm sendo disseminados através do uso de programas que ajudam os engenheiros a utilizá-los adequadamente em seus projetos tendo em vista que resultam em estruturas mais leves e de fácil fabricação. Desta forma, houve a necessidade de desenvolver um sistema CAD/CAE, para automatizar a geração das geometrias das estruturas planas, além das representações gráficas do sistema geral tridimensional de contraventamentos da estrutura - CAD; exportar os dados para um programa integrado que realiza um processo otimizado de toda a análise estrutural e dimensionamento - CAE e, finalmente, retornar os dados processados para o ambiente CAD, para realizar o detalhamento automático das ligações da estrutura treliçada analisada. Todos os procedimentos adotados para automação dos projetos seguem recomendações de normas técnicas brasileiras principalmente a NBR8800/1986 / Abstract: This work has as objective to show a software that have the goal to automate the main stages of a steel structural design, using AutoLISP and Delphi5 languages. The steel structural designs in case are the roofs formed by plane trusses made by hollow sections frames. These hollow steel sections, which are not highly used in plane structures in Brazil, are being disseminated by the use of softwares that help civil engineers to use them correctly in their designs, in view of that they result in less weighted and easy manufactured structures. So, there is the necessity to develop a CAD/CAE system, that will automate the generation of the geometries from plane structures and the graphical designs from the three-dimentional general system - CAD; also, we have the necessity to export the data to an integrated computer program that executes an optimized process from the entire structural analysis and design - CAE; and, finaly, to return the proceeded data back to CAD environment, to draw the automatic details from the connections of the analyzed structure. All the procedures and methods used to automate the design follows the specifications of Brazilian Design Codes, mainly the NBR-8800/1986 / Mestrado / Estruturas / Mestre em Engenharia Civil
110

Concepção de proteses mioeletricos de membros superiores baseado no estudo fisiologico / Conception of upper limbs myoelectrical prosthesis based on physiological study

Vidal, Tabata 25 February 2008 (has links)
Orientador: Helder Anibal Hermini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-11T07:22:27Z (GMT). No. of bitstreams: 1 Vidal_Tabata_M.pdf: 5227439 bytes, checksum: 003d20540fa55512408c2b363171f23c (MD5) Previous issue date: 2008 / Resumo: O objetivo deste trabalho foi revisar na literatura os desenvolvimentos da aplicação das tecnologias envolvidas em automação dedicadas às próteses mioelétricas de membros superiores, desde os primeiros trabalhos implementados no período pós-Segunda Guerra Mundial até as soluções tecnológicas atualmente utilizadas. O conceito de prótese mioelétrica envolve a aquisição e tratamento do sinal mioelétrico de um membro residual que é usado para acionar um atuador que ativará a ferramenta terminal. Objetivando a elaboração de uma solução compatível e aplicável harmonicamente ao sistema orgânico, foram realizados estudos da anatomia, da fisiologia articular dos membros superiores, da natureza e características do sinal mioelétrico, além das tecnologias envolvidas para a concepção de protótipos mecatrônicos, tais como técnicas de CAD-CAE-CAM e a geração de circuitos eletrônicos dedicados à coleta e tratamento de sinais mioelétricos. Para validar o desenvolvimento teórico, três protótipos da ferramenta terminal foram confeccionados, sendo testados em nível de bancada / Abstract: The goal of this work was to review the specialized literature for the development of technological applications connected with automation of myoelectrical prosthesis of upper limbs throughout the years, from World War 2 post-war solutions to the technology currently applied. The concept of myoelectrical prosthesis presupposes implies the acquisition and treatment of the myoelectrical signal of a residual limb which is used to start an actuator, which in turn activates the terminal tool. Aiming at encountering a solution that could be both compatible and harmoniously applicable to the human body, the author engaged in studying anatomy, upper limbs articular physiology, the nature and characteristics of the myoelectrical signal in addition to the technologies utilized to conceive mechatronic prototypes, i.e. CAD-CAE-CAM and the creation of dedicated electronic circuits to collect and process the myoelectrical signals. To validate the theoretical foundation of this project, three prototypes of terminal tools were manufactured and bench-tested. / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

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