Der Vortrag demonstriert am Beispiel eines Designraumes die Kombination aus einem FE-Werkzeug mit parametrischen Untersuchungen.

This work deals with the bearing capacity of wood based I-joists Finite element models were analyzed to determine the bearing capacity of I-joists, using the finite element software Abaqus CAE. The purpose of this study is to compare the results from the developed FE-models with experimental results, and with a previously proposed design formula. To perform the analyses finite element models were created. The model consists of three parts:, the web (made of shell element), the flanges and steel plates used at the supports and loading points (made of solid elements) To determine the bearing capacity of the I-joist two types of analyses were performed, a linear buckling analysis to check the risk of web buckling and a static (stress) analysis to check the risk of splitting of the flanges. This study shows that the steel plate length, in some cases, has little or no impact on primarily the splitting load. Furthermore, the buckling load decreases as the depth of the beam increases, the influence of the depth being proportional to 1/h2. The depth of the beam has no impact on the risk of splitting of the flange.

The goal in this thesis was to reduce a multilayer shim model, which was modeled from steel and polymer (isotropic materials), into an equivalent single layer shim model. The procedure was to use mathematical formulations to convert a multilayer shim into an ESL (equivalent single layer) shim. Here, a transverse isotropic model is used to prepare for future orthotropic layers. The results show that the ESL model behaves isotropically. In the 2 layer model there was no squeal noise whereas in the ESL models there is.

Originally presented as the author's Thesis--Helmut-Schmidt-Universität, Hamburg, 2008. / Includes bibliographical references.

Electronic Design Automation (EDA) tools are today very capable computer programs supporting electronic engineers with the design of printed circuit board (PCB). All tools have their strengths and weaknesses; when choosing the right tool many factors needs to be taken into consideration aside from the tools themselves. Companies need to focus on the product and revenues for a business to be viable. Depending on the knowledge and strengths of the company, the choice of tools varies. The decision should be based on the efficiency of the tools and the functions necessity for the company rather than the price tags. The quality and availability of support for the tools, training costs, how long will it take to put the tool in operation and present or future collaboration partners is equally important factors when deciding the right tool. The absence of experience and knowledge of the current tool within a company is a factor which could affect important operation; therefore it is important to provide training and education on how to use the tool to increase its efficiency. Providing training and education can be a large expense, but avoids changes within and makes the business competitive. The choice of EDA tool should be based on the employed engineer’s current knowledge and experience of the preferred tool. If the employed engineer’s knowledge and experience varies too much, it might be preferable to make a transition to one of the tool by training and education. Product lifecycle management (PLM) is a data management system and business activity management system which focuses on the lifecycle of a product. To manage the lifecycle of a product it is necessary to split the lifecycle into stages and phases for a more manageable and transparent workflow. By overseeing a product’s entire lifecycle there are benefits which affects many areas. PLM greatest benefits for EDA are collaboration across separate groups and companies by working together through a PLM platform, companies can forge strong design chains that combine their best capabilities to deliver the product to the customers. This report is a study on evaluating which EDA suits the company with consideration of the employed engineer’s demands, requests and competence. The interests in PLM made the company suggest a short theory study on PLM and EDA benefits.

This dissertation aims to advance the field of structural optimization by creating and demonstrating new methodologies for the explicit inclusion of manufacturing issues. The case of composite aerospace structures was a main focus of this work as that field provides some of the greatest complexities in manufacturing yet also provides the greatest incentives to optimize structural performance. Firstly, the possibilities for modifying existing FEA based structural optimization methods to better capture manufacturing constraints are investigated. Examples of brick-based topology optimization, shell-based topology optimization, parametric sizing optimization and manufacturing process optimization are given. From these examples, a number of fundamental limitations to these methods were observed and are discussed. The key limitation that was uncovered related to a dichotomy between analytical methods (such as FEA) and CAD-type methods. Based on these observations, a new Knowledge-Based framework for structural optimization was suggested whereby manufacturing issues are integrally linked to the more conventional structural issues. A prototype system to implement this new framework was developed and is discussed. Finally, the validity of the framework was demonstrated by application to a generic composite rib design problem.

Zugl.: Paderborn, University, Diss., 2005.

Com o avanço tecnológico dos computadores e o desenvolvimento de programas de simulação de fluidos, propiciando resultados cada vez mais sofisticados e eficazes, ocorreu uma redução significativa no tempo e nos custos computacionais para conceber veículos mais seguros e com menos agressão ao meio ambiente, devido ao seu menor consumo de combustível. Contudo, mesmo com o uso da Dinâmica dos Fluidos Computacional bastante disseminado, ainda são divergentes as informações sobre o nível de concordância esperado entre os resultados obtidos, por meio da simulação, quando comparada com os resultados medidos experimentalmente. Este trabalho apresenta uma sequencia metodológica para determinação das forças de arrasto sobre um veículo de transporte de pessoas (ônibus), de maneira a transmitir a compreensão dos fenômenos que envolvem o problema, a sequencia necessária de simulações e conceitos que devem ser atribuídos para obtenção de respostas coerentes. Primeiramente é abordada a análise de problemas com respostas experimentais disponíveis e assim validando a metodologia de simulação para cada parâmetro abordado, domínio, malha, discretização da camada limite e modelos de turbulência. Com base nas definições destes parâmetros são realizadas as simulações de um problema em escala real do escoamento de fluidos sobre um ônibus. A metodologia empregada para estimar os parâmetros de simulação é apresentada em forma de uma sequencia de cálculos, de fácil utilização. Os resultados demonstram que o uso do método numérico na criação de veículos pode ser ampliado, com significativa redução de ensaios experimentais. A análise numérica apresentada ratifica a metodologia numérica como importante ferramenta para aprimorar o projeto de veículos, com menor coeficiente de arrasto e maior estabilidade aerodinâmica, com isto proporcionando a redução do consumo de combustível, somados com benefícios secundários significativos, tais como, baixo acúmulo de sujeira, melhorando a visibilidade, ruído aerodinâmico reduzido e até menor fadiga do condutor. / The technological advancement of computers and the development of fluid simulation software providing results increasingly sophisticated and effective, has resulted in a significant reduction in time and computational cost to develop safer vehicles with less harm to the environment due to its lower fuel consumption. However, even with quite widespread Computational Fluid Dynamics use, there is still conflicting information on the expected level of agreement among the results obtained by simulation, when compared with the experimentally measured results. This work presents a methodological sequence to determine the drag force on a vehicle for people transportation (bus ), in order to convey the understanding of phenomena involving the problem , the required sequence of simulations, and concepts that should be assigned to obtain coherent answers. At first, one approaches the analysis of problems with available experimental answers, thus validating the simulation methodology for each parameter approached, domain , mesh ,discretization of the boundary layer and turbulence models. Based on the definitions of these parameters, simulations of an actual scale problem of fluid flow on a bus are performed. The methodology used to estimate the simulation parameters is presented in the form of a sequence of calculations easy to use. The results show that the use of the numerical method for creating vehicles can be expanded with a significant reduction in experimental tests. The numerical analysis presented confirms the numerical methodology as an important tool to upgrade the design of vehicles, with lower drag coefficient and greater aerodynamic stability, thus providing a reduction of fuel consumption, added to significant secondary benefits, such as low dirt accumulation, improving visibility, reduced aerodynamic noise and even less driver fatigue.

Com o avanço tecnológico dos computadores e o desenvolvimento de programas de simulação de fluidos, propiciando resultados cada vez mais sofisticados e eficazes, ocorreu uma redução significativa no tempo e nos custos computacionais para conceber veículos mais seguros e com menos agressão ao meio ambiente, devido ao seu menor consumo de combustível. Contudo, mesmo com o uso da Dinâmica dos Fluidos Computacional bastante disseminado, ainda são divergentes as informações sobre o nível de concordância esperado entre os resultados obtidos, por meio da simulação, quando comparada com os resultados medidos experimentalmente. Este trabalho apresenta uma sequencia metodológica para determinação das forças de arrasto sobre um veículo de transporte de pessoas (ônibus), de maneira a transmitir a compreensão dos fenômenos que envolvem o problema, a sequencia necessária de simulações e conceitos que devem ser atribuídos para obtenção de respostas coerentes. Primeiramente é abordada a análise de problemas com respostas experimentais disponíveis e assim validando a metodologia de simulação para cada parâmetro abordado, domínio, malha, discretização da camada limite e modelos de turbulência. Com base nas definições destes parâmetros são realizadas as simulações de um problema em escala real do escoamento de fluidos sobre um ônibus. A metodologia empregada para estimar os parâmetros de simulação é apresentada em forma de uma sequencia de cálculos, de fácil utilização. Os resultados demonstram que o uso do método numérico na criação de veículos pode ser ampliado, com significativa redução de ensaios experimentais. A análise numérica apresentada ratifica a metodologia numérica como importante ferramenta para aprimorar o projeto de veículos, com menor coeficiente de arrasto e maior estabilidade aerodinâmica, com isto proporcionando a redução do consumo de combustível, somados com benefícios secundários significativos, tais como, baixo acúmulo de sujeira, melhorando a visibilidade, ruído aerodinâmico reduzido e até menor fadiga do condutor. / The technological advancement of computers and the development of fluid simulation software providing results increasingly sophisticated and effective, has resulted in a significant reduction in time and computational cost to develop safer vehicles with less harm to the environment due to its lower fuel consumption. However, even with quite widespread Computational Fluid Dynamics use, there is still conflicting information on the expected level of agreement among the results obtained by simulation, when compared with the experimentally measured results. This work presents a methodological sequence to determine the drag force on a vehicle for people transportation (bus ), in order to convey the understanding of phenomena involving the problem , the required sequence of simulations, and concepts that should be assigned to obtain coherent answers. At first, one approaches the analysis of problems with available experimental answers, thus validating the simulation methodology for each parameter approached, domain , mesh ,discretization of the boundary layer and turbulence models. Based on the definitions of these parameters, simulations of an actual scale problem of fluid flow on a bus are performed. The methodology used to estimate the simulation parameters is presented in the form of a sequence of calculations easy to use. The results show that the use of the numerical method for creating vehicles can be expanded with a significant reduction in experimental tests. The numerical analysis presented confirms the numerical methodology as an important tool to upgrade the design of vehicles, with lower drag coefficient and greater aerodynamic stability, thus providing a reduction of fuel consumption, added to significant secondary benefits, such as low dirt accumulation, improving visibility, reduced aerodynamic noise and even less driver fatigue.

Submitted by João Arthur Martins (joao.arthur@ufpe.br) on 2015-03-05T18:05:44Z No. of bitstreams: 2 dissertação de José Ricardo Menezes3_Definitivo.pdf: 8016285 bytes, checksum: 6836a5a08efb99012d720c033bcee7af (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-05T18:05:44Z (GMT). No. of bitstreams: 2 dissertação de José Ricardo Menezes3_Definitivo.pdf: 8016285 bytes, checksum: 6836a5a08efb99012d720c033bcee7af (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2012-04-17 / Este estudo apresenta a utilização de recursos CAD e CAE como ferramentas de desenvolvimento de novos produtos com proposição ao aumento dos índices de confiabilidade. Para atingir esta meta buscou-se a implementação de um componente do sistema de conformação mecânica por injeção em uma indústria fabricante de chuveiros elétricos. A aplicação de ferramentas qualitativas detectou as falhas críticas do referido sistema e delimitou uma especificação de projeto para concepção de alternativa de solução. A análise por elementos finitos (FEA), permitiu a construção de um novo modelo de agulha para o molde de injeção em consonância às premissas estabelecidas. Decorrido o período da implantação e ajustes pertinentes coletou-se novas amostras da aplicação prática, cujo objetivo foi comparar aos resultados do sistema convencional. Os resultados consolidados corroboram para um aumento significativo dos critérios de desempenho observados, sobretudo no que concerne às funções taxa de falhas, MTTF, e confiabilidade, permitindo-se inferir que os recursos computacionais, constituem-se como alternativa insofismável para resolução dos problemas projetuais desta natureza.