The goal of this thesis is the development of theoretical methods targeting the implementation of topology optimization in structural engineering applications. In civil engineering applications, structures are typically assemblies of many standardized components, such as bars, where the largest gains in efficiency can be made during the preliminary design of the overall structure. The work is aimed mainly at truss-like structures in civil engineering applications, however several of the developments are general enough to encompass continuum structures and other areas of engineering research too. The research aims to address the following challenges:<p>- Discrete variable optimization, generally necessary for truss problems in civil engineering, tends to be computationally very expensive,<p>- the gap between industrial applications in civil engineering and optimization research is quite large, meaning that the developed methods are currently not fully embraced in practice, and<p>- industrial applications demand robust and reliable solutions to the real-world problems faced by the civil engineering profession.<p><p>In order to face these challenges, the research is divided into several research papers, included as chapters in the thesis.<p>Discrete binary variables in structural topology optimization often lead to very large computational cost and sometimes even failure of algorithm convergence. A novel method was developed for improving the performance of topology optimization problems in truss-like structures with discrete design variables, using so-called Kinematic Stability Repair (KSR). Two typical examples of topology optimization problems with binary variables are bracing systems and steel grid shell structures. These important industrial applications of topology optimization are investigated in the thesis. A novel method is developed for topology optimization of grid shells whose global shape has been determined by form-finding. Furthermore a novel technique for façade bracing optimization is developed. In this application a multiobjective approach was used to give the designers freedom to make changes, as the design advanced at various stages of the design process. The application of the two methods to practical<p>engineering problems, inspired a theoretical development which has wide-reaching implications for discrete optimization: the pitfalls of symmetry reduction. A seemingly self-evident method of cardinality reduction makes use of geometric symmetry reduction in structures in order to reduce the problem size. It is shown in the research that this assumption is not valid for discrete variable problems. Despite intuition to the contrary, for symmetric problems, asymmetric solutions may be more optimal than their symmetric counterparts. In reality many uncertainties exist on geometry, loading and material properties in structural systems. This has an effect on the performance (robustness) of the non-ideal, realized structure. To address this, a general robust topology optimization framework for both continuum and truss-like structures, developing a novel analysis technique for truss structures under material uncertainties, is introduced. Next, this framework is extended to discrete variable, multiobjective optimization problems of truss structures, taking uncertainties on the material stiffness and the loading into account. Two papers corresponding to the two chapters were submitted to the journal Computers and Structures and Structural and Multidisciplinary Optimization. Finally, a concluding chapter summarizes the main findings of the research. A number of appendices are included at the end of the manuscript, clarifying several pertinent issues. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

Though lots of numerical methods have been proposed in the literature to optimize me-chanical structures at the final stage of the design process, few designers use these tools since the first stage. However, a minor modification at the first step can bring significant change to the global performances of the structure. Usually, during the initial stage, models are based on theoretical and empirical equations, which are often characterized by mixed variables: continuous (e.g. geometrical dimensions), discrete (e.g. the cross section of a beam available in a catalogue) and/or integer (e.g. the number of layers in a composite material). Furthermore, the functions involved may be non differentiable, or even discontinuous. Therefore, classical algorithms based on the computation of sensi-tivities are no more applicable. <p><p>Consequently, to solve these problems, the most wide-spread meta-heuristic methods are evolutionary algorithms (EAs), which work as follows: the best individuals among an initial population of randomly generated potential solutions are favoured and com-bined (by specific operators like crossover and mutation) in order to create potentially better individuals at the next generation. The creation of new generations is repeated till the convergence is reached. The ability of EAs to explore widely the design space is useful to solve single-objective unconstrained optimization problems, because it gener-ally prevents from getting trapped into a local optimum, but it is also well known that they do not perform very efficiently in the presence of constraints. Furthermore, in many industrial applications, multiple objectives are pursued together. <p><p>Therefore, to take into account the constrained and multicriteria aspects of optimization problems in EAs, a new method called PAMUC (Preferences Applied to MUltiobjectiv-ity and Constraints) has been proposed in this dissertation. First the user has to assign weights to the m objectives. Then, an additional objective function is built by linearly aggregating the normalized constraints. Finally, a multicriteria decision aid method, PROMETHEE II, is used in order to rank the individuals of the population following the m+1 objectives. <p><p>PAMUC has been validated on standard multiobjective test cases, as well as on the pa-rametrical optimization of the purge valve and the feed valve of the Vinci engine, both designed by Techspace Aero for launcher Ariane 5.<p>\ / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished

Indiana University-Purdue University Indianapolis (IUPUI) / Structural optimization of vehicle components for blast mitigation seeks to counteract the damaging effects of an impulsive threat on occupants and critical components. The strong and urgent need for improved protection from blast events has made blast mitigating component design an active research subject. Standard up-armoring of ground vehicles can significantly increase the mass of the vehicle. Without concurrent modifications to the power train, suspension, braking and steering components, the up-armored vehicles suffer from degraded stability and mobility. For these reasons, there is a critical need for effective methods to generate lightweight components for blast mitigation. The overall objective of this research is to make advances in structural design methods for the optimization of lightweight blast-mitigating systems. This thesis investigates the automated design process of isotropic plates to mitigate the effects of blast loading by addressing the design of blast-protective structures from a design optimization perspective. The general design problem is stated as finding the optimum shape of a protective shell of minimum mass satisfying deformation and envelops constraints. This research was conducted in terms of three primary research projects. The first project was to investigate the design of lightweight structures under deterministic loading conditions and subject to the same objective function and constraints, in order to compare feasible design methodologies through the expansion of the problem dimension in order to reach the limits of performance. The second research project involved the investigation of recently developed uncertainty quantification methods, the univariate dimensional reduction method and the performance moment integration method, to structures under stochastic loading conditions. The third research project involved application of these uncertainty quantification methods to problems of design optimization under uncertainty, in order to develop a methodology for the generation of lightweight reliable structures. This research has resulted in the construction of a computational framework, incorporating uncertainty quantification methods and various optimization techniques, which can be used for the generation of lightweight structures for blast mitigation under uncertainty. Applied to practical structural design problems, the results demonstrate that the methodologies provide a practical tool to aid the design engineer in generating design concepts for blast-mitigating structures. These methods can be used to advance research into the generation of reliable structures under uncertain loading conditions inherent to blast events.

<div>Topology Optimization is an optimization technique used to synthesize models without any preconceived shape. These structures are synthesized keeping in mind the minimum compliance problems. With the rapid improvement in advanced manufacturing technology and increased need for lightweight high strength designs topology optimization is being used more than ever.</div><div>There exist a number of commercially available software's that can be used for optimizing a product. These software have a robust Finite Element Solver and can produce good results. However, these software offers little to no choice to the user when it comes to selecting the type of optimization method used.</div><div>It is possible to use a programming language like MATLAB to develop algorithms that use a specific type of optimization method but the user himself will be responsible for writing the FEA algorithms too. This leads to a situation where the flexibility over the optimization method is achieved but the robust FEA of the commercial FEA tool is lost.</div><div>There have been works done in the past that links ABAQUS with MATLAB but they are primarily used as a tool for finite element post-processing. Through this thesis, the aim is to develop an interface that can be used for solving optimization problems using different methods like hard-kill as well as the material penalization (SIMP) method. By doing so it's possible to harness the potential of a commercial FEA software and gives the user the requires flexibility to write or modify the codes to have an optimization method of his or her choice. Also, by implementing this interface, it can also be potentially used to unlock the capabilities of other Dassault Systèmes software's as the firm is implementing a tighter integration between all its products using the 3DExperience platform.</div><div>This thesis as described uses this interface to implement BESO and HCA based topology optimization. Since hybrid cellular atomata is the only other method other than equivalent static load method that can be used for crashworthiness optimization this work suits well for the role when extended into a non-linear region.</div>

Submitted by Maria Cristina (library@lncc.br) on 2017-05-03T14:14:27Z No. of bitstreams: 1 Dissertacao.pdf: 824609 bytes, checksum: 3fd1774255594b6d69f7fe7522aec9a2 (MD5) / Approved for entry into archive by Maria Cristina (library@lncc.br) on 2017-05-03T14:14:53Z (GMT) No. of bitstreams: 1 Dissertacao.pdf: 824609 bytes, checksum: 3fd1774255594b6d69f7fe7522aec9a2 (MD5) / Made available in DSpace on 2017-05-03T14:15:03Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 824609 bytes, checksum: 3fd1774255594b6d69f7fe7522aec9a2 (MD5) Previous issue date: 2017-02-21 / Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) / The study of bilevel optimization problems arouses particular interest given their ability to represent hierarchical decision structures, but the challenges in their resolution require the development of appropriate computational techniques. This work aims at the solution of a class of bilevel problems where the objective function in the follower agent is linear or quadratic in the follower variables and linear constraints may be present. With the use of the Karush-Kuhn-Tucker conditions, it was verified the possibility of solving the follower level as a linear complementarity problem, giving rise to a nested approach. In this approach, the follower response is obtained by Lemke's algorithm, while the leader level is treated with the differential evolution metaheuristic, in view of its good results and great generality. The proposed technique is submitted to a test-set using instances from the literature, as well as others, proposed in this work, with the intent of validating the use of Lemke's algorithm in the follower level, and study its computational performance. / O estudo do problema de otimização em dois níveis desperta particular interesse dada sua capacidade de representar estruturas hierárquicas de decisão, mas as dificuldades na sua resolução exigem o desenvolvimento de técnicas computacionais adequadas. Este trabalho tem como foco a solução de uma classe de problemas em dois níveis onde a função objetivo do agente seguidor é linear ou quadrática nas variáveis do seguidor e com restrições lineares. Utilizando-se então as condições de Karush-Kuhn-Tucker, verificou-se a possibilidade de resolução do nível do seguidor como um problema de complementaridade linear, dando origem a uma abordagem aninhada. Nesta, a resposta do seguidor é obtida pelo algoritmo de Lemke, enquanto o nível do líder é tratado pela metaheurística evolução diferencial, tendo em vista os bons resultados desta e sua grande generalidade. A técnica proposta é submetida a um conjunto de testes utilizando instâncias da literatura bem como outras, propostas neste trabalho, com o objetivo de validar a utilização do algoritmo de Lemke e estudar seu desempenho computacional.

Os mecanismos flexíveis são dispositivos capazes de transmitir força e movimento através da deformação elástica. Têm grande importância a uma série de aplicações nas quais os mecanismos de corpos rígidos não seriam viáveis, como por exemplo, os sistemas microeletromecânicos. Existem várias maneiras pelas quais os mecanismos flexíveis podem ser projetados, sendo a otimização topológica um método bastante difundido por ser de aplicação sistemática, ou seja, não requer do projetista qualquer ação analítica durante a etapa de projeto. Na maioria dos casos, o método da otimização topológica combina o método dos elementos finitos com um método de programação matemática. Logo, faz-se necessário discretizar a região do espaço na qual o material disponível será distribuído para determinar o mecanismo flexível adequado à aplicação desejada. Freqüentemente, o mecanismo projetado apresenta duas regiões sólidas unidas por um único nó pertencente à malha de elementos finitos. Durante a transmissão do movimento, este nó age como uma dobradiça conectada às duas regiões. Trata-se de um efeito indesejado, pois compromete a modelagem e a fabricação do componente mecânico. Assim, neste trabalho, foram estudadas técnicas destinadas à redução da ocorrência das \"dobradiças\" no projeto de mecanismos flexíveis por otimização topológica. Foi implementado em linguagem C um código que permite projetar mecanismos flexíveis submetidos a um único carregamento ou múltiplos carregamentos (mecanismos multi-flexíveis). Com o objetivo de analisar e explorar outros aspectos da formulação implementada no código, investigou-se também a sua utilização no projeto de estruturas rígidas. Como resultado, é mostrada a influência dos diversos parâmetros de otimização no projeto de mecanismos flexíveis sem dobradiças, permitindo analisar a eficácia da formulação implementada. / Compliant mechanisms are devices capable of transmitting force and displacement through elastic deformation. They are extremely important for a number of applications in which the mechanisms of rigid bodies would not be feasible, such as microelectromechanical systems. There are several ways through which compliant mechanisms can be designed, being topology optimization a highly diffused method because of its systematic application, once, it does not require from the designer any analytical action during the stage of the project. In most cases, topology optimization method combines the finite element method with a mathematical program method. Therefore, it is necessary to discretize the region of the space in which the available material will be distributed to determine the appropriate compliant mechanism for the desired application. However, the mechanism designed often presents two solid regions united by one single node. During movement transmission, this node acts as a hinge connected to both regions. This is an undesired effect, as it compromises the modeling and manufacturing of the mechanical component. Thus, this work covers techniques aiming at reducing the occurrence of hinges in the design of compliant mechanisms through topology optimization. A code in C language was implemented, which allows the design of compliant mechanisms subjected to one single load or multiple loads (multi-compliant mechanisms). With the purpose of analyzing and exploring other aspects of the formulation implemented in the code, its use in the design of rigid structures was also investigated. As a result, the influence of several optimization parameters in the design of compliant mechanisms without hinges is shown. This allows to analyze the efficiency of the formulation implemented.

[pt] Há uma tendência global crescente na adoção do paradigma Building Information Modeling (BIM) para a implementação em projetos de arquitetura, engenharia e construção (AEC). No Brasil, uma comissão nomeada pelo governo estuda como disseminar o BIM aplicado a projetos governamentais. Ao mesmo tempo, a Otimização Estrutural (OE) vêm recebendo atenção em projetos de engenharia civil para reduzir o material e melhorar o desempenho estrutural. O objetivo deste trabalho, portanto, é entender como a OE pode ser inserido em um projeto BIM, analisando especificamente a interface entre arquitetos e engenheiros estruturais. A investigação incluiu uma Revisão Sistemática da Literatura (SLR) para compreender o cenário científico atual nessas áreas. Foi observado que existe uma lacuna científica em trabalhos que conectam a OE dentro do BIM. Para ajudar a preencher essa lacuna, foi desenvolvida uma estrutura de Manual de Entrega de Informações (MEI) que mapeia o fluxo de informações para conectar arquitetos e engenheiros por meio da OE em um ambiente BIM. A metodologia proposta foi aplicada a três estudos de caso de complexidade crescente. Verificou-se que a OE pode ser inserido em um projeto BIM quando os problemas de interoperabilidade e colaboração forem aprimorados. Para validar as soluções estruturais com base nos resultados da OE, foi desenvolvida e analisada a análise detalhada usando Modelos de Elementos Finitos (MEF). Verificou-se que as soluções eram estruturalmente aceitáveis de acordo com os códigos de projeto atuais. No entanto, podem ser necessárias técnicas avançadas de construção para serem economicamente viáveis. Vale ressaltar que este estudo se limitou a projetos de construção habituais nos estágios iniciais de desenvolvimento do projeto. / [en] There has been an increasing global tendency in the adoption of Building Information Modeling (BIM) paradigm for the implementation of Architectural, Engineering, and Construction (AEC) projects. In Brazil, a governmental nominated commission is studying how to disseminate BIM as applied to governmental projects. At the same time, Structural Optimization (SO) has received a lot of attention in civil engineering applications to reduce material and enhance structural performance. The purpose of this work, thus, is to understand how SO can be inserted in a BIM project, specifically analyzing the interface between architects and structural engineers. The investigation included a Systematic Literature Review (SLR) to comprehend the current scientific scenario in these areas. It was observed that there is a scientific gap in works that connect SO and BIM. To help fill this gap, an Information Delivery Manual (IDM) structure was developed which maps the information flow to connect architects and engineers through SO in a BIM environment. The proposed methodology was applied to three experiments of increasing complexity. It was verified that SO can be inserted in a BIM project once interoperability and collaboration issues are improved. To validate the structural solutions based on the SO results, detailed analysis using Finite Element Models (FEM) were developed and analyzed. It was found that the solutions were structurally acceptable according to current design codes. However, they may require advanced construction techniques to be economically feasible. It is worth pointing out that this study was limited to usual building projects in the early stages of the design.

Muitas vezes encontram-se na Engenharia, estruturas que contenham fluido em seu interior, (estruturas com fluido contido). Uma vez que para determinados casos de carregamento, como por exemplo, carregamento hidrostático, o fluido colabora com a rigidez, pode ser conveniente para o engenheiro considerar a presença deste fluido com o objetivo de se obter uma estrutura mais leve, principalmente nos casos onde a presença do fluido é obrigatória à operação da estrutura. Nesta dissertação, uma metodologia para otimização de estruturas com fluido contido é apresentada. Tal metodologia engloba a otimização de uma estrutura real, utilizando otimização paramétrica (OP) e topológica (OT). A rotina de OT implementada permite projetar estruturas compostas de aço e fluido contido (FC), e considera múltiplos casos de carregamento, peso próprio e a possibilidade de escolha de regiões a serem otimizadas ou não. Para validação da rotina de OT, exemplos clássicos da literatura considerando a presença de um ou dois materiais são apresentados. Para implementar o algoritmo para resolução da OT utiliza-se um programa comercial para a análise de elementos finitos, complementado com uma rotina externa elaborada em linguagem do próprio programa. Isto possibilita agregar a vantagem da utilização de um programa comercial, multidisciplinar, e com um grande número de elementos finitos implementados, com a versatilidade de uma linguagem de programação, permitindo implementar uma solução específica para o problema estudado. Como exemplo, apresenta-se um estudo de caso real, voltado a estruturas navais, apresentando, além da análise da estrutura inicial estudada, uma otimização paramétrica, e uma otimização topológica tridimensional da estrutura. Os resultados alcançados, mostram-se satisfatórios, uma vez que a estrutura obtida no estudo de caso específico apresenta uma redução significativa em seu peso atendendo aos requisitos de projeto. / Several times, it is found in Engineering, structures with fluid inside (contained fluid structures). Since for some load cases, for instance, hydrostatic load, the fluid collaborates with stiffness, it may be convenient for the engineer to take into account this fluid to make the structure lighter, mainly if the presence of fluid is mandatory for operation. In this work, a methodology for contained fluid structures optimization is presented. This methodology includes parametric and topology optimizations of a real structure. Topology optimization routine implemented allows us to design structures made by steel and contained fluid, and includes several load cases, self-weight, and the possibility of choosing areas to optimize or not. To validate the topology optimization routine, classical examples with one or two material are showed. To perform topology optimization procedure, Finite Element Analysis commercial software is applied together with an external routine implemented using the software programming language, this allows us to take advantage of a multidisciplinary commercial software, which has a large number of finite elements implemented, and the versatility of a customized program for the studied problem. As an example, it is showed a real case, within naval structures describing the initial structure analysis and its parametric optimization, and a tridimensional topology optimization. The results obtained are satisfactory, since the final structure obtained has a significant reduction in its weight.

O projeto de um componente mecânico é uma atividade muito complexa, onde muitas vezes se tem restrições de projeto como peso do componente e rigidez máxima, e também restrições de manufatura, associada aos processos de fabricação disponíveis para serem utilizados. É fato conhecido que a Otimização Topológica (OT), apesar de ser um método extremamente eficiente para a obtenção de soluções ótimas, gera soluções com geometrias complexas que são ou muito caras de se fabricar ou infactíveis. A técnica de projeção foi escolhida como adequada para implementar as restrições propostas neste trabalho. Esta técnica resolve o problema posto num domínio de variáveis de projeto e projeta essa solução num domínio de pseudo-densidades, que são a resposta do problema. A relação entre os dois domínios e determinada pela função de projeção e pelo mapeamento das variáveis definidos de forma diferente para cada restrição. Neste trabalho foram implementadas restrições de manufatura para OT de modo a restringir a gama possível de soluções no problema de otimização. Como exemplo foi considerado o problema de maximização de rigidez, com restrição de volume. Todas as implementações foram realizadas em linguagem de programação C, e o algoritmo de otimização utilizado é o critério de optimalidade. Foram implementadas as seguintes restrições de manufatura com a técnica de projeção: membro mínimo, buraco mínimo, simetria, extrusão, é revolução, repetição de padrões, fundição, forjamento, e laminação. Estas restrições mostram a grande capacidade da técnica de projeção para controlar a solução do problema de otimização sem implicar num grande aumento do custo computacional. Os resultados encontrados mostram a potencialidade de utilizar restrições de manufatura na OT, porém estão longe de esgotarem o assunto, nesse tema recente que vem sendo explorado no Método de Otimização Topológica (MOT). / The design of a mechanical component is a very complex task, which includes constraints such as maximum weight and maximum stiffness, and also manufacturing constraints, associated with the manufacturing processes required at the shop floor. It is known that Topology Optimization (TO), despite of being a very effective and powerful method to obtain optimal solutions, generates solutions with complex geometries that are too much expensive to be manufactured or just can not be made. The projection scheme has been chosen as the most appropriate technique for implementing the proposed constraints. This scheme solves the proposed problem in a domain of design variables and then projects these results into a pseudo-density domain to find the solution. The relation between both domains is defined by the projection function and variable mapping defined in a different way for each constraint. In this work, manufacturing constraints for TO are implemented in a way that the possible solutions of the optimization problem are restricted. As an example, the traditional stiffness maximization problem is considered. All implementations have been done using C programming language, and the optimization algorithm applied is the optimality criteria. The following manufacturing constraints have been implemented using the projection scheme: minimal member size, minimal hole size, symmetry, extrusion, revolution, pattern repetition, casting, forging and lamination. These constraints show the large capacity of the projection scheme to control the solution for the optimization without adding a large computational cost. The results that have been found show the great power of using manufacturing constraints in the TO, however, they are far from exhausting this topic that has been recently explored in the Topology Optimization Method (TOM).

Risers são elementos que fazem a conexão física entre a plataforma e o poço. Eles são fundamentais na explotação de petróleo no mar. O projeto destes elementos é, cada vez mais, uma tarefa desafiadora, devido ao aumento da profundidade de explotação, que pode tornar inviável a utilização de uma configuração mais tradicional, como a catenária. Para viabilizar a explotação através de risers, surgem outras configurações, entre elas a lazy-wave, que foi estudada neste texto. Um riser deve atender a critérios de engenharia quando submetido a diversas condições ambientais. Cada uma destas condições é simulada numericamente o que, devido à complexidade do problema, demanda um grande tempo computacional. Considerando-se que, dado um campo, existe um grande número de possibilidades de configurações de risers, o tempo necessário para uma busca exaustiva pela melhor configuração é grande demais, tornando o resultado do projeto altamente dependente da experiência do projetista. Neste trabalho foi proposta uma abordagem diferente, atacando o problema por três frentes: o uso de técnicas de otimização para tomada de decisão sobre as configurações a serem simuladas, com o objetivo de diminuir o número de simulações necessárias, a realização das simulações através de modelos capazes de diminuir o tempo de simulação de cada condição ambiental, e o uso de computação paralela, por meio da qual o trabalho computacional é dividido entre vários núcleos, permitindo maior rapidez na obtenção dos resultados. Para aplicar as técnicas de otimização, foi necessário transformar o projeto de um riser em um problema de otimização, definindo variáveis de projeto, restrições e função objetivo. Em seguida estudaram-se os métodos de otimização aplicáveis ao problema e estes foram implementados em uma ferramenta computacional. Os modelos utilizados para realização das análises dinâmica e estática foram trabalhados tanto para generalização quanto para aumento de robustez e de confiabilidade. A ferramenta desenvolvida foi aplicada a um caso real e os resultados apresentados, através dos quais foi estudada a influência das condições ambientais (movimentos do topo, correntezas e offsets) utilizadas. Dois algoritmos heurísticos e quatro de programação matemática foram também comparados, os primeiros tanto em sua versão serial quanto na paralela. Comparações entre diferentes funções objetivo foram feitas, tendo o melhor resultado sido obtido minimizando a máxima amplitude de tensão dinâmica. Através da minimização desta função, a resposta dinâmica do riser é aprimorada, tendo sido obtidos resultados que mostram que é possível conseguir em pouco tempo e de maneira automática uma configuração que satisfaz os critérios de engenharia aplicáveis a este tipo de projeto e que é a melhor de acordo com uma medida objetiva de eficiência. / Risers are elements that physically connect the platform to the well. They are fundamental elements in sea oil exploitation. Their project is a challenging task, due to the continuous increase in exploitation depth, which can turn infeasible the use of more traditional configurations, such as the free-hanging. To make the exploitation feasible, other configurations are possible, among them the lazy-wave, which was studied in this text. A riser must fulfill engineering criteria under several environmental conditions. Each of these environmental conditions is numerically simulated and, due to the complexity of the problem, the required computational time is high. If one considers that, in a given field, a great number of riser possibilities exists, the time required for a comprehensive search for the best configuration is too large, making the project outcome highly dependent on the designers experience. In this work a different approach was proposed, in three fronts: the use of an optimization technique to decide which configurations will be simulated; in order to reduce the number of necessary simulations, the execution of the simulations using models which are capable of reducing simulation time for each environmental condition; and the use of parallel computing, through which the computational burden is divided among several cores, leading to a faster solution. In order to apply an optimization technique, it was necessary to transform a riser design into an optimization problem, defining design variables, restrictions and objective function. Then, applicable optimization methods were studied and implemented in a computational tool. The models used for the execution of the dynamic and static analyses were generalized and tweaked, so that a better reliability and robustness could be achieved. The developed tool was applied to a real case and the results presented, through which were studied the influence of environmental conditions (top movements, currents and offsets). Two heuristic and four mathematical programming optimization algorithms were also compared, the first both in serial and parallel versions. Comparisons among different objective functions were made, with the best result being obtained by minimizing the maximum dynamic stress amplitude. Through the minimization of this function, the dynamic response of the riser is improved, with results which show that it is possible to obtain in a short time and in an automated way a configuration that fulfills the applicable engineering criteria and that is the best, according to an objective performance measure.