A new simplified skyscraper analysis model (SSAM) was developed and implemented in a spreadsheet to be used for preliminary skyscraper design and teaching purposes. The SSAM predicts linear and nonlinear response to gravity, wind, and seismic loading of "modern" skyscrapers which involve a core, megacolumns, outrigger trusses, belt trusses, and diagonals. The SSAM may be classified as a discrete method that constructs a reduced system stiffness matrix involving selected degrees of freedom (DOF's). The steps in the SSAM consist of: 1) determination of megacolumn areas, 2) construction of stiffness matrix, 3) calculation of lateral forces and displacements, and 4) calculation of stresses. Seven configurations of a generic skyscraper were used to compare the accuracy of the SSAM against a space frame finite element model. The SSAM was able to predict the existence of points of contraflexure in the deflected shape which are known to exist in modern skyscrapers. The accuracy of the SSAM was found to be very good for displacements (translations and rotations), and reasonably good for stress in configurations that exclude diagonals. The speed of execution, data preparation, data extraction, and optimization were found to be much faster with the SSAM than with general space frame finite element programs.

Cette thèse introduit le concept de comportement géométrique d'un assemblage mécanique. Cette notion permet de rendre compte du caractère assemblable ou mobile d'un mécanisme sous la forme d'un système de relations algébriques entre les paramètres géométriques permettant de le décrire. Dans un premier temps, cette thèse montre l'intérêt de ce concept pour traiter des problèmes faisant intervenir plusieurs effets physiques et plusieurs scénarios d'utilisation. Ce chapitre est appliqué à l'étude de l'assemblabilité d'un treillis pyramidal de conception à 4 barres décrit par un modèle géométrique non cartésien issu de la littérature. Dans un second temps, après avoir constaté le manque de modèles adaptés permettant de représenter des mécanismes mobiles, ce travail en propose un non cartésien. Il détaille aussi une méthode de mise en équation afin de traduire la mobilité d'un mécanisme. Une application de ce modèle et de la méthode est également faite. Elle permet de résoudre localement le problème de la mobilité d'un mécanisme de Bennett. Enfin, la dernière partie de ce travail expose une solution pour associer et comparer deux objets décrits par des représentations non cartésiennes. Cette technique est utile pour comparer deux états physiques du même objet utilisé dans différents scénarios pour assurer le suivi d'une exigence géométrique. Elle peut également être utilisée pour associer des objets réels et des objets idéalisés pour traiter des problèmes de tolérancement / This thesis introduces the concept of geometrical behavior of mechanical assembly. The geometrical behavior is constituted by a set of algebraic relations that translate the assemblability or mobility conditions of a product. It is expressed thanks to a specific geometrical model for the early phases of product design. Firstly, this work shows the interest of the geometrical behavior to tackle multi-physics problems at the early stages of product design. This part is illustrated on a ten bar pyramid subjected to mechanical and thermal strains. Secondly, this thesis proposes a coordinate free geometrical model dedicated to the representation of mobile mechanisms. This part also indicates a technique to express the mobility conditions of a loop as mathematical equations. An application of these model and technique is proposed to express the geometrical behavior of the Bennett mechanism. Finally, this work exposes a solution to associate and compare two objects described in the above-mentioned coordinate free model. This technique is useful to compare two states of the same object used under different operating conditions. It can also be used to associate ideal and real objects to tackle tolerancing issues.

Techniques for preliminary analysis of various tall building systems subjected to lateral loads have been studied herein. Three computer programs written in Matlab® graphical user interface language for use on any personal computer are presented. Two of these programs incorporate interactive graphics. A program called Wall_Frame_2D is introduced for two-dimensional analysis of shear wall-frame interactive structures, using the shear-flexural cantilever analogy. The rigid outrigger approach was utilized to develop a program called Outrigger Program to analyze multi-outrigger braced tall buildings. In addition, a program called Frame Tube was developed which allows analysis of single and quad-bundled framed tube structures. The tube grids are replaced with an equivalent orthotropic plate, and the governing differential equations are solved in closed form. Results for lateral deflections, rotations, and moment, shear, and torque distributions within the various resisting elements are compared against other preliminary and "exact" matrix analysis methods for several examples. SAP2000 was used to obtain "exact" results. The approximate analyses are found to give reasonable results and a fairly good indication of the behavior of the actual structure. These programs are proposed for inclusion in a knowledge-based approach to preliminary tall building design. The tall building design process is outlined and criteria are given for the incorporation of these "Resource Level Knowledge Modules" into an integrated tall building design system.

Lorsqu’un concepteur de systèmes d’électronique de puissance est engagé dans un processus de pré-design, c’est-à-dire la définition du cahier des charges du système, il doit surmonter plusieurs difficultés. La première étant de trouver grâce à son expérience et à la littérature, toutes les architectures, topologies de conversion et technologies de composants susceptibles de répondre aux besoins du système.A partir de cette éventail, le concepteur doit en éliminer un certain nombre via des arguments qualitatifs ou quantitatifs jusqu’à ce qu’il n’en reste plus qu’un nombre très restreint. Il est primordial pour le concepteur que parmi les choix restant, celui-ci en connaisse les limites de design pour définir avec certitude le plan de développement du produit et les problématiques futures à résoudre. En d’autres termes, il lui faut définir la juste formulation du problème qui lui est posée.Posséder une méthode lui permettant d’atteindre cet objectif en toute confiance et dans les délais impartis est fortement désirable. Ceci est l’objet de cette thèse.Nous proposons donc une nouvelle approche basée sur le pré-dimensionnement par optimisation dans le monde continu (imaginaire) de systèmes d’électronique de puissance. La méthode proposée utilise en effet un algorithme d’optimisation basé sur le calcul du gradient du modèle du système. Cet algorithme permet de gérer un très grand nombre de paramètres de design, autrement dit permet d’explorer un large éventail de solutions dans le monde imaginaire. Il nécessite donc des modèles de systèmes d’électronique de puissance continus et dérivables avec des variables d’optimisation continues (imaginaires) malgré le caractère discret des composants utilisés en électronique.Les présents travaux de thèse ont donc consistés à proposer des modèles d’optimisation continus et dérivables d’un convertisseur Buck entrelacé utilisé dans un aéronef appelé « Stratobus » et à valider ces modèles d’optimisation par une démarche expérimentale sur un prototype complet. Ces modèles ont ensuite été utilisés pour le pré-dimensionnement de ce convertisseur dans le cadre du projet Stratobus permettant dans un premier temps une étude sur le mode de conduction et les matériaux magnétique minimisant la masse du convertisseur, puis une analyse de l’impact de variation de cahier des charges sur la masse du convertisseur. Enfin, les convertisseurs étant construits à partir de composants électroniques choisis sur étagère, une procédure de discrétisation a été mise en place pour revenir au monde réel. / When a designer of power electronics systems is involved in a pre-design process, i.e. the definition of the system specifications, he/she has to overcome several difficulties. The first is to find, based on its experience and literature, all the architectures, conversion topologies and component technologies that can meet the needs of the system.From this list of possibilities, the designer must eliminate a certain number of them via qualitative or quantitative arguments until only a small number remains. It is essential for the designer that he/she knows the design limits of each remaining choices to define with certainty the product development plan and the future design issues to be solved. In other words, it must define the correct problem formulation.Having a method to achieve this objective with confidence and on schedule is highly desirable. This is the purpose of this thesis.We therefore propose a new approach based on preliminary design by optimization in the continuous (imaginary) world of power electronics systems. The proposed method uses an optimization algorithm based on the calculation of the gradient of the system model. This algorithm allows to manage a very large number of design parameters, in other words to explore a wide range of solutions in the imaginary world. It therefore requires continuous and differentiable models of power electronics systems with continuous (imaginary) optimization variables despite the discrete nature of the components used in electronics.The present thesis work has thus consisted in proposing continuous and derivable optimization models of an interleaved Buck converter used in an aircraft called "Stratobus" and validating these optimization models by an experimental approach on a complete prototype. These models have then been used for the pre-dimensioning of this converter as part of the Stratobus project. Firstly a study on the conduction mode and magnetic materials minimizing the mass of the converter has been performed. And then the impact of variation of the specifications on the mass of the converter has been analyzed. Finally, since the converters are built from electronic components chosen off the shelf, a discretization procedure has been set up to return to the real world.

The flying-wing is a type of configuration which is a tailless airplane accommodating all of its parts within the outline of a single airfoil. Theoretically, it has the most aerodynamic efficiency. The fuel consumption can be more efficient than the existed conventional airliner. It seems that this configuration can achieve the above mentioned requirements. According to these outstanding advantages, many aircraft companies did a great deal of projects on the flying-wing concept. However, the application was only for sport and military use; for airliner, none of them entered production. FW-11 is a flying-wing configuration airliner which is a design cooperation between Cranfield University and Aviation Industry Corporation of China (AVIC). Aiming the spatial economic and environmental needs, this 200-seat airliner would attract attention from airline companies for cost saving and environmental protection. Before start, this program is designated for a new generation commercial aircraft to compete with the existing same capability airliner, such as Airbus A320 and Boeing 767. As the first team of this program, the aim is to finish the conceptual design and prepare the relevant document for next two teams that will perform preliminary and detail design. As a member of FW-11 program and as part of the GDP, the author has been through the four conceptual design stages: engine manufacturers, aircraft family issues, structure design and the establishment of 3-D CAD model. The aim of IRP study is to focus on the initial fuselage design.

De nos jours, les entreprises doivent faire face à une situation économique de plus en plus concurrentielle qui les oblige à développer de plus en plus rapidement des produits de plus en plus complexes. C’est dans ce contexte que sont apparus les systèmes mécatroniques, fruits de l’intégration de technologies issues de la mécanique, l’électronique, l’informatique et l’automatique. Ces systèmes mécatroniques sont particulièrement complexes à concevoir pour les bureaux d’étude en raison des niveaux d’intégration fonctionnelle et techniques, nécessitant une forte coordination entre les différents ingénieurs, de différentes disciplines. Il est par conséquent nécessaire de fournir aux concepteurs de nouveaux outils permettant de mieux concevoir, de manière plus efficace, des produits mécatroniques, optimisés tant du point de vue fonctionnel que performanciel. La thèse présentée dans ce mémoire vise à proposer aux concepteurs des outils permettant de concevoir des architectures mécatronique et de les optimiser, dans les phases amont du processus de conception (conception architecturale). Nous présentons dans un premier temps notre démarche de conception globale, comprenant quatre niveaux de conception et permettant, en détaillant progressivement les architectures mécatroniques dans les différents niveaux, de construire plusieurs architectures permettant de répondre à un besoin client, tout en satisfaisant aux normes et législations en vigueur. Dans un deuxième temps, nous proposons une démarche d’optimisation permettant d’employer des techniques d’optimisation combinatoire afin d’automatiser une partie du processus de conception architecturale, en particulier la phase visant à construire les architectures produits à partir d’un ensemble de principes de solution ou de solutions techniques. Nous montrons enfin dans un troisième temps l’application des étapes de notre démarche globale, ainsi que de notre démarche d’optimisation combinatoire, afin de résoudre un problème visant à développer une éolienne de moyenne puissance pour l’alimentation d’un gîte de montagne. / Nowadays, industries should face a more and more competitive economic situation that forces them to faster develop increasingly complex products. This is in this context that appeared mechatronic systems, the fruit of the integration of technologies from mechanical, electrical, computer and control engineering. These mechatronic systems are particularly complex to design for R&D designers as they require strong coordination between the engineers from different specialities to reach the required levels of functional and technical integration. It is therefore necessary to provide new design tools and approaches to better and more efficiently design mechatronic products and optimize their functionalities as well as their performance. The thesis presented in this manuscript aims to provide design approaches to the designers to design and optimize mechatronic architectures from the early design phases (embodiment design). We first present our global design approach, with four design levels to build and gradually detail mechatronic architectures to meet customer needs as well as the standards and legislation. Secondly, we propose an combinatorial optimization-based approach to computerize some parts of the architectural design process, especially the phase where architectures are built from a set solution of principles or technical solutions. We finally show how the design and optimization approaches have been applied to solve a design problem aiming to develop a medium power wind turbine for supplying a mountain cottage.

abstract: Tall buildings are spreading across the globe at an ever-increasing rate (www.ctbuh.org). The global number of buildings 200m or more in height has risen from 286 to 602 in the last decade alone. The increasing complexity of building architecture poses unique challenges in the structural design of modern tall buildings. Hence, innovative structural systems need to be evaluated to create an economical design that satisfies multiple design criteria. Design using traditional trial-and-error approach can be extremely time-consuming and the resultant design uneconomical. Thus, there is a need for an efficient numerical optimization tool that can explore and generate several design alternatives in the preliminary design phase which can lead to a more desirable final design. In this study, we present the details of a tool that can be very useful in preliminary design optimization - finite element modeling, design optimization, translating design code requirements into components of the FE and design optimization models, and pre-and post-processing to verify the veracity of the model. Emphasis is placed on development and deployment of various FE models (static, modal and dynamic analyses; linear, beam and plate/shell finite elements), design optimization problem formulation (sizing, shape, topology and material selection optimization) and numerical optimization tools (gradient-based and evolutionary optimization methods) [Rajan, 2001]. The design optimization results of full scale three dimensional buildings subject to multiple design criteria including stress, serviceability and dynamic response are discussed. / Dissertation/Thesis / M.S. Civil Engineering 2014

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Topic of Diploma thesis is „Reconstruction of the weir in the Brantice village.“ The theoretical part of their focus deals with the definition and putting patterns associa-ted with the design-ing reconstruction of the weir. In the practical part were made three proposals reconstructions of the weir, which are mathematically based, graphically pre-sented and discussed.

In the highly competitive aerospace industry, engine manufacturers must react very quickly and precisely to any demand emerging from aircraft manufacturers if they want to be positioned on the offer. This is especially true when answering to Requests For Information (RFI) based on preliminary design investigations of first level. In order to reduce the time needed to perform these costly operations while improving the performances achieved, Snecma wishes to develop tools for dimensioning the engine and also for assessing key parameters such as mass, emissions, fuel burn, costs, etc. Unfortunately, the set of tools and the process used at the present time for preliminary design investigations of first level are not sufficient to meet the high standards sought-after by the company in terms of time and performances. As a consequence, efforts must be spent on redefining the whole process and the tools it is based on; here is the mission that has been conferred upon me.   Multiple exchanges with performances engineers and specialists allowed to draw the current process for preliminary design investigations of first level and raise all the associated concerns. At the same time, a status of the existing tools (called modules in this report), mainly developed under Excel, has been realised in order to identify the range of action for today's investigations. A prototype has been developed under SDK Python with the aim of proving the feasibility of a solution to a difficulty that shows up in the process for each new investigation: the one of generating the workflow on the optimisation software Optimus. A target process has finally been discussed considering all the information collected, and would allow dividing by five the time needed to perform investigations compare to now. The prototype developed lead to interesting results and this solution could thus probably be integrated in the target process as it would allow saving one day of work for an engineer for each study to be carried out.   Solutions have been proposed to all the concerns identified in the process and they will have to be discussed with many actors and investigated further in the near future in order to set the target process that will allow meeting the final objective of answering all types of RFIs emitted by aircraft manufacturer in a very short time with a high level of confidence in the results.