The field of bridge monitoring is one of rapid development. Advances in sensor technologies, in data communication and processing algorithms all affect the possibilities of Structural Monitoring in Bridges. Bridges are a very critical part of a country’s infrastructure, they are expensive to build and maintain, and many uncertainties surround important factors determining their serviceability and deterioration state. As such, bridges are good candidates for monitoring. Monitoring can extend the service life and avoid or postpone replacement, repair or strengthening works. The amount of resources saved, both to the owner and the users, by reducing the amount of non-operational time can easily justify the extra investment in monitoring. This thesis consists of an extended summary and five appended papers. The thesis presents advances in sensor technology, damage identification algorithms, Bridge Weigh-In-Motion systems, and other techniques used in bridge monitoring. Four case studies are presented. In the first paper, a fully operational Bridge Weigh-In-Motion system is developed and deployed in a steel railway bridge. The gathered data was studied to obtain a characterization of the site specific traffic. In the second paper, the seasonal variability of a ballasted railway bridge is studied and characterized in its natural variability. In the third, the non-linear characteristic of a ballasted railway bridge is studied and described stochastically. In the fourth, a novel damage detection algorithm based in Bridge Weigh-In-Motion data and machine learning algorithms is presented and tested on a numerical experiment. In the fifth, a bridge and traffic monitoring system is implemented in a suspension bridge to study the cause of unexpected wear in the bridge bearings. Some of the major scientific contributions of this work are: 1) the development of a B-WIM for railway traffic capable of estimating the load on individual axles; 2) the characterization of in-situ measured railway traffic in Stockholm, with axle weights and train configuration; 3) the quantification of a hitherto unreported environmental behaviour in ballasted bridges and possible mechanisms for its explanation (this behaviour was shown to be of great importance for monitoring of bridges located in colder climate) 4) the statistical quantification of the nonlinearities of a railway bridge and its yearly variations and 5) the integration of B-WIM data into damage detection techniques. / <p>QC 20140910</p>

The goal of this dissertation is to evaluate the effectiveness of model predictive control (MPC) for a magnetically suspended flywheel energy storage uninterruptible power supply (FlyUPS). The reason this research topic was selected was to determine if an advanced control technique such as MPC could perform better than a classical control approach such as decentralised Proportional-plus-Differential (PD) control. Based on a literature study of the FlyUPS system and the MPC strategies available, two MPC strategies were used to design two possible MPC controllers were designed for the FlyUPS, namely a classical MPC algorithm that incorporates optimisation techniques and the MPC algorithm used in the MATLAB® MPC toolbox™. In order to take the restrictions of the system into consideration, the model used to derive the controllers was reduced to an order of ten according to the Hankel singular value decomposition of the model. Simulation results indicated that the first controller based on a classical MPC algorithm and optimisation techniques was not verified as a viable control strategy to be implemented on the physical FlyUPS system due to difficulties obtaining the desired response. The second controller derived using the MATLAB® MPC toolbox™ was verified to be a viable control strategy for the FlyUPS by delivering good performance in simulation. The verified MPC controller was then implemented on the FlyUPS. This implementation was then analysed in order to validate that the controller operates as expected through a comparison of the simulation and implementation results. Further analysis was then done by comparing the performance of MPC with decentralised PD control in order to determine the advantages and limitations of using MPC on the FlyUPS. The advantages indicated by the evaluation include the simplicity of the design of the controller that follows directly from the specifications of the system and the dynamics of the system, and the good performance of the controller within the parameters of the controller design. The limitations identified during this evaluation include the high computational load that requires a relatively long execution time, and the inability of the MPC controller to adapt to unmodelled system dynamics. Based on this evaluation MPC can be seen as a viable control strategy for the FlyUPS, however more research is needed to optimise the MPC approach to yield significant advantages over other control techniques such as decentralised PD control. / Thesis (MIng (Computer and Electronic Engineering))--North-West University, Potchefstroom Campus, 2013

Condition monitoring of critical machinery has many economic benefits. The primary objective is to detect faults, for example on rolling element bearings, at an early stage to take corrective action prior to the catastrophic failure of a component. In this context, it is important to be able to discriminate between stable and deteriorating fault conditions. A number of conventional vibration analysis techniques exist by which certain faults in rotating machinery may be identified. However, under circumstances involving multiple fault conditions conventional condition monitoring techniques may fail, e.g. by indicating deteriorating fault conditions for stable fault situations or vice versa. Condition monitoring of rotating machinery that may have multiple, possibly simultaneous, fault conditions is investigated in this thesis. Different combinations of interacting fault conditions are studied both through experimental methods and simulated models. Novel signal processing techniques (such as cepstral analysis and equidistant Fourier transforms) and pattern recognition techniques (based on the nearest neighbour algorithm) are applied to vibration problems of this nature. A set of signal processing and pattern recognition techniques is developed for the detection of small incipient mechanical faults in the presence of noise and dynamic load (imbalance). In the case investigated the dynamic loading consisted of varying degrees of imbalance. It is demonstrated that the proposed techniques may be applied successfully to the detection of multiple fault conditions. / Thesis (Ph.D. (Electronical Engineering))--North-West University, Potchefstroom Campus, 2004.

ABSTRACT NON-LINEAR MATHEMATICAL MODELING OF GEAR-ROTOR-BEARING SYSTEMS INCLUDING BEARING CLEARANCE G&Uuml / RKAN, Niyazi Ersan M.S. Department of Mechanical Engineering Supervisor: Prof. Dr. H. Nevzat &Ouml / ZG&Uuml / VEN November 2005, 130 pages In this study, a non-linear mathematical model of gear-rotor systems which consists of elastic shafts on elastic bearings with clearance and coupled by a non-linear gear mesh interface is developed. The mathematical model and the software (NLGRD 2.0) developed in a previous study is extended to include the non-linear effects due to bearing clearances by using non-linear bearing models. The model developed combines the versatility of using finite element method and the rigorous treatment of non-linear effect of backlash and bearing clearances on the dynamics of the system. The software uses the output of Load Distribution Program (LDP), which computes loaded static transmission error and mesh compliance for the contact points of a typical mesh cycle, as input. Although non-varying mesh compliance is assumed in the model, the excitation effect of time varying mesh stiffness is indirectly included through the loaded static transmission error, which is taken as a displacement input into the system. Previous computer program which was written in Fortran 77 is rewritten by using MatLAB 7.0 and named as NLGRD (Non-Linear Geared Rotor Dynamics) Version 3.0. The program is highly flexible and open to further developments. The program calculates dynamic to static load ratio, dynamic transmission error, forces and displacements at bearings. The mathematical model suggested and the code (NLGRD version 3.0) are validated by comparing the numerical results obtained from the model suggested with experimental data available in literature. The results are also compared with those of previously developed non-linear models. The effects of different system parameters such as bearing stiffness, bearing clearance and backlash on the gears are investigated. The emphasis is placed on the interaction of clearances in bearings with other system parameters.

Orientador: Katia Lucchesi Cavalca Dedini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-19T16:37:25Z (GMT). No. of bitstreams: 1 Lima_EvertonNogueira_M.pdf: 5132802 bytes, checksum: 225e85d3342a471d6630511c11ffdf77 (MD5) Previous issue date: 1996 / Resumo: As máquinas rotativas cujos eixos são suportados ou direcionados por mancais hidrodinâmicos possuem certos comportamentos dinâmicos característicos. Quando o rotor está em movimento o atrito viscoso do filme de óleo e o movimento relativo entre as partes internas do eixo e do mancal produzem uma distribuição de pressões. A pressão atuando sobre a superfície do rotor provoca uma força hidrodinâmica não-linear, dependente de sua posição no mancal, da velocidade de rotação e das condições do fluido. O conhecimento dessas forças é de fundamental importância na análise do movimento vibratório para os equipamentos. O trabalho consiste na apresentação da dedução de modelos matemáticos não-lineares que possam representar a força hidrodinâmica exercida pelo óleo dos mancais sobre uma máquina rotativa vertical de rotor flexível. As forças não lineares são avaliadas por um método analítico baseado na posição orbital do eixo do rotor. Essas forças, assim como o desbalanceamento excêntrico, são as fontes de excitação do sistema, e estão incluídas na equação de seu movimento. Uma característica particular do método é a rapidez da solução para as forças não-lineares. Para complementar o trabalho, o comportamento dinâmico característico do sistema à esta excitação é analisado pelas amplitudes das órbitas mostradas graficamente para algumas condições de operação / Abstract: Rotating machinery possessing rotors which are supported or guided by journal bearings has certain characteristic dynamical behavior. When a rotor is running, the viscous friction in the oil film and the relative movement among the internal part generates a pressure distribution inside. This pressure acting upon the rotor surface yields a non-linear hydrodynamic force which depends on its position and the fluid condition in the journal bearings. The acknowledgment of these forces is of fundamental importance in the analysis of the vibratory motion for the equipments. This work consists in the presentation of non-linear mathematical models that are able to represent the hydrodynamic force exerted by the oil in the bearings of a rotating machine, assembled on a vertical and flexible shaft. The non-linear forces are evaluated using an analytical method based in the orbital position of the rotor axis. These forces, as well as those from eccentric unbalance, are the excitation sources for the system and are included in its equation of motion. A particular characteristic of this method is the speed obtained to calculate the non-linear forces. In order to complete the work, the characteristic dynamical behavior of the system to this excitation is analyzed by means of the orbits graphically plotted for some running conditions / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

Afin d’introduire de nouvelles fonctions dans les commandes de vol d’hélicoptère, il est nécessaire d’augmenter les bandes passantes de leurs actionneurs. La modélisation réaliste de l’ensemble du système d’actionnement, rendant compte de ses limitations de puissance et de sa consommation énergétique, ainsi que l’amélioration des technologies existantes des dispositifs d’étanchéité et de guidage sont les deux enjeux principaux permettant d’atteindre la durée de vie souhaitée à hautes fréquences. Pour supporter ce nouveau développement, ce travail s’organise en trois parties. Une première partie présente l’état de l’art des commandes de vol de l’hélicoptère. Une architecture générique d’actionneur est proposée ainsi que la terminologie associée. Une deuxième partie porte sur l’élaboration d’un modèle de connaissance détaillé à l’aide du formalisme Bond-graph pour le système d’actionnement. Un effort particulier est porté sur la standardisation des composants et de leurs interfaces dans une démarche orientée objet. La dernière partie traite concerne les dispositifs d’étanchéité et de guidage au niveau des vérins de commande de vol. Compte tenu de l’objectif d’utiliser des paliers fluides, les différentes manières de générer une force normale au sein d’un film fluide sont analysées. Puis, une étude plus approfondie des butées hydrostatiques et des paliers hybrides coniques est ensuite conduite en tenant compte des contraintes propres à l’aéronautique. L’ensemble des connaissances acquises sont appliquées à un cas concret de développement assisté par les modèles d’actionneur hautes fréquences pour le contrôle actif de rotor. / In order to introduce new functions in helicopter flight controls, it is necessary to increase the bandwidths of their actuators. A realistic modelling of the entire actuating system, taking into account its power limitations and its energy consumption, as well as the improvement of the existing sealing and guiding device technologies are the two main challenges to reach the desired high frequency without reducing dramatically the actuator lifespan. To support this new development, this work is organized in three parts. A first part presents the state of the art of the helicopter flight controls. A generic actuator architecture is proposed as well as the associated terminology. A second part deals with the development of a detailed knowledge-model using the Bond-graph formalism for the actuating system. A particular effort is made to standardize the components and their interfaces in an object-oriented approach. The last part deals with the sealing and guiding devices of flight control cylinders. Given the objective of using fluid bearings, the various ways of generating a normal force within a fluid film are analyzed. Then, a more detailed study of the hydrostatic thrust bearings and the conical hybrid bearings is then carried out taking into account the constraints specific to aeronautics. All the knowledge acquired is applied to a concrete case of development, aided by the models, of high frequency actuators for the active control of a rotor.

Abstract : Over the past three decades, various fields have witnessed a successful application of active magnetic bearing (AMB) systems. Their favorable features include supporting high-speed rotation, low power consumption, and rotor dynamics control. Although their losses are much lower than roller bearings, these losses could limit the operation in some applications such as flywheel energy storage systems and vacuum applications. Many researchers focused their efforts on boosting magnetic bearings energy efficiency via minimizing currents supplied to electromagnetic coils either by a software solution or a hardware solution. According to a previous study, we adopt the hardware solution in this thesis. More specifically, we investigate developing an efficient and yet simple control scheme for regulating a permanent magnet-biased active magnetic bearing system. The control objective here is to suppress the rotor vibrations and reduce the corresponding control currents as possible throughout a wide operating range. Although adopting the hardware approach could achieve an energy-efficient AMB, employing an advanced control scheme could achieve a further reduction in power consumption. Many advanced control techniques have been proposed in the literature to achieve a satisfactory performance. However, the complexity of the majority of control schemes and the potential requirement of powerful platform could discourage their application in practice. The motivation behind this work is to improve the closed-loop performance without the need to do model identification and following the conventional procedure for developing a model-based controller. Here, we propose applying the hybridization concept to exploit the classical PID control and some nonlinear control tools such as first- and second-order sliding mode control, high gain observer, backstepping, and adaptive techniques to develop efficient and practical control schemes. All developed control schemes in this thesis are digitally implemented and validated on the eZdsp F2812 control board. Therefore, the applicability of the proposed model-free techniques for practical application is demonstrated. Furthermore, some of the proposed control schemes successfully achieve a good compromise between the objectives of rotor vibration attenuation and control currents minimization over a wide operating range. / Résumé: Au cours des trois dernières décennies, divers domaines ont connu une application réussie des systèmes de paliers magnétiques actifs (PMA). Leurs caractéristiques favorables comprennent une capacité de rotation à grande vitesse, une faible consommation d'énergie, et le contrôle de la dynamique du rotor. Bien que leurs pertes soient beaucoup plus basses que les roulements à rouleaux, ces pertes pourraient limiter l'opération dans certaines applications telles que les systèmes de stockage d'énergie à volant d'inertie et les applications sous vide. De nombreux chercheurs ont concentré leurs efforts sur le renforcement de l'efficacité énergétique des paliers magnétiques par la minimisation des courants fournis aux bobines électromagnétiques soit par une solution logicielle, soit par une solution matérielle. Selon une étude précédente, nous adoptons la solution matérielle dans cette thèse. Plus précisément, nous étudions le développement d'un système de contrôle efficace et simple pour réguler un système de palier magnétique actif à aimant permanent polarisé. L'objectif de contrôle ici est de supprimer les vibrations du rotor et de réduire les courants de commande correspondants autant que possible tout au long d'une large plage de fonctionnement. Bien que l'adoption de l'approche matérielle pourrait atteindre un PMA économe en énergie, un système de contrôle avancé pourrait parvenir à une réduction supplémentaire de la consommation d'énergie. De nombreuses techniques de contrôle avancées ont été proposées dans la littérature pour obtenir une performance satisfaisante. Cependant, la complexité de la majorité des systèmes de contrôle et l'exigence potentielle d’une plate-forme puissante pourrait décourager leur application dans la pratique. La motivation derrière ce travail est d'améliorer les performances en boucle fermée, sans la nécessité de procéder à l'identification du modèle et en suivant la procédure classique pour développer un contrôleur basé sur un modèle. Ici, nous proposons l'application du concept d'hybridation pour exploiter le contrôle PID classique et certains outils de contrôle non linéaires tels que contrôle par mode glissement du premier et du second ordre, observateur à grand gain, backstepping et techniques adaptatives pour développer des systèmes de contrôle efficaces et pratiques. Tous les systèmes de contrôle développés dans cette thèse sont numériquement mis en oeuvre et évaluées sur la carte de contrôle eZdsp F2812. Par conséquent, l'applicabilité des techniques de modèle libre proposé pour l'application pratique est démontrée. En outre, certains des régimes de contrôle proposés ont réalisé avec succès un bon compromis entre les objectifs au rotor d’atténuation des vibrations et la minimisation des courants de commande sur une grande plage de fonctionnement.

La conception des turbomachines à haute densité énergétique nécessite de plus en plus la maîtrise d'un plus grand nombre de paramètres fonctionnels. La moindre défaillance d'un composant conduit quasi immédiatement la machine à la rupture. C'est en particulier le cas pour le comportement des composants à films minces.L'appellation "film mince" correspond à tout espace de très faible épaisseur situé entre le rotor et le stator de la turbomachine. Leur but est soit de limiter les fuites de manière à optimiser les performances intrinsèques de la machine, soit alors à supporter et stabiliser le rotor. Ces derniers cas sont plus appelés communément "joints lisses ou annulaires" et "paliers fluides".Lorsqu'un fluide circule dans un espace de très faible épaisseur, typiquement quelques centièmes de millimètres sur une distance très longue, son champ de vitesses, donc de pression, dépend fortement des phénomènes visqueux aux parois dont l'une est mise en rotation et l'autre est immobile. Les efforts fluides sur ces parois peuvent être alors importants et doivent être pris en compte dans le dimensionnement de la machine.La connaissance précise de ces écoulements très complexes est indispensable pour déterminer les efforts statiques et dynamiques appliqués au rotor de manière à pouvoir dimensionner un fonctionnement calme. / The design of high performance aerospace turbo pumps requires more control of an increasing number of functional parameters. Any component failure led almost immediately to a machine failure. This is particularly the case for the behavior of thin film lubricated components.The term "thin film" means any thin space between the rotor and the stator of the engine. Their goal is either to limit leakage to maximize the machine intrinsic performance, or to support and stabilize the rotor. These cases are more commonly called "smooth or annular seals" and "fluid film bearings".When a fluid flows in a space of very small thickness, typically a few hundredths of a millimeter, the velocity field, hence the pressure, are highly dependent on the walls viscous forces. Fluid forces on the walls (which one is rotated and the other is stationary) can then be important and should be taken into account in the design of the machine.The precise knowledge of these complex flows is essential to determine the static and dynamic forces applied to the rotor to ensure a quite functioning of the turbo pump.

Parmi les techniques utilisées en maintenance, l'analyse vibratoire reste l'outil le plus efficace pour surveiller l'état interne des machines tournantes en fonctionnement. En effet l'état de chaque composant constituant la machine peut être caractérisé par un ou plusieurs indicateurs de défaut issus de l'analyse vibratoire. Le suivi de ces indicateurs permet de détecter la présence d'un défaut et même de le localiser. Cependant, l'évolution de ces indicateurs peut être influencée par d'autres paramètres comme la variation de charge, la vitesse de rotation ou le remplacement d'un composant. Cela peut provoquer des fausses alarmes et remettre en question la fiabilité du diagnostic. Cette thèse a pour objectif de combiner l'analyse vibratoire avec la méthode de reconnaissance des formes afin d'une part d'améliorer la détection de défaut des composants en particulier le défaut de roulement et d'autre part de mieux suivre l'évolution de la dégradation pour caractériser le degré de sévérité du défaut. Pour cela nous avons développé des méthodes de classification dynamique pour prendre en compte l'évolution du système. Les observations à classifier sont constituées d'indicateurs de défauts et des combinaisons linéaires de ceux-ci. La démarche de la reconnaissance des formes dynamique consiste à extraire, à sélectionner et à classifier ces observations de façon continue. Trois méthodes de classification dynamiques ont été développées durant cette thèse : le « Dynamic DBSCAN » qui la première version dynamique de DBSCAN développée pour pouvoir suivre les évolutions des classes, « Evolving scalable DBSCAN » ESDBSCAN qui représente une version en ligne et évolutive de DBSCAN et finalement « Dynamic Fuzzy Scalabale DBSCAN » DFSDBSCAN qui est une version dynamique et floue de la méthode de classification ESDBSCAN adaptée pour un apprentissage en ligne. Ces méthodes distinguent les variations des observations liées au changement du mode de fonctionnement de la machine (variation de vitesse ou de charges) et les variations liées au défaut. Ainsi, Elles permettent de détecter, de façon précoce, l'apparition d'un défaut qui se traduit par la création d'une nouvelle classe dite classe dégradée et de suivre l'évolution de celle-ci. Cette méthodologie permettrait d'améliorer l'estimation de la durée de vie résiduelle du composant en analysant la distance séparant la classe "saine" et "dégradée". L'application sur des données réelles a permis d'identifier les différents états du roulement au cours temps (sain ou normal, défectueux) et l'évolution des observations liée à la variation de vitesse et au changement de charges avec un taux d'erreur faible et d'établir un diagnostic fiable. Afin de caractériser le degré de précocité du diagnostic des méthodes développées nous avons comparé ces résultats avec ceux établis par des méthodes classiques de détection. Cette comparaison nous a montré que les méthodes proposées permettent un diagnostic plus précoce et plus fiable.Mots clés : Diagnostic et suivi, roulements, méthodes de reconnaissance des formes, apprentissage en ligne, classification dynamique, analyse vibratoire, DFSDBSCAN, ESDBSCAN, DDBSCAN. / Various techniques can be used in rotating machines condition based maintenance. Among which vibration analysis remains the most popular and most effective tool for monitoring the internal state of an operating machine. Through vibration analysis, the state of each component constituting the machine can be characterized by one or more fault indicators. Monitoring these indicators can be used to detect the presence of a defect or even locate it. However, the evolution of these indicators can be influenced by other parameters than defect such as the variation of load, speed or replacement of a component. So counting solely on the evolution of these fault indicators to diagnose a machine can cause false alarms and question the reliability of the diagnosis.In this thesis, we combined vibration analysis tools with pattern recognition method to firstly improve fault detection reliability of components such as bearings, secondly to assess the severity of degradation by closely monitor the defect growth and finally to estimate their remaining useful life. For these reasons, we have designed a pattern recognition process capable of; identifying defect even in machines running under non stationary conditions, processing evolving data of an evolving system and can handle an online learning. This process will have to decide the internal state of the machine using only faults indicators or linear combinations of fault indicators.The process of pattern recognition of dynamic forms consists of extracting and selecting useful information, classify these observations continuously into their right classes then decide on an action according to the observations' class.Three dynamic classification methods have been developed during this thesis: Dynamic DBSCAN that was developed to capitalize on the time evolution of the data and their classes, Evolving Scalable DBSCAN (ESDBSCAN) that was created to overcome the shortcoming of DDBSCAN in online processing and finally Dynamic Fuzzy Scalable DBSCAN (DFSDBSCAN); a dynamic fuzzy and semi-supervised version of ESDBSCAN. These methods can detect the observations evolution and identify the nature of the change causing it; either if it's a change in operating mode of the machine (speed variation or load) or a change related to the defect.With these techniques we were are able to enhance the reliability of fault detection by identifying the origin of the fault indicators evolution. An evolution caused by an alteration of the operating mode and changes caused by defect result in two different types of classes evolution (the appearance of a new class we named it 'defected' in case of defect or a drift otherwise). Not only that but these techniques helped us enhance the precocity of the fault detection and estimate the remaining useful life of the monitored component as well by analyzing the distance separating the class 'healthy' and 'defected'.The application of the designed process on real data helped us prove the legitimacy of the proposed techniques in identifying the different states of bearings over time (healthy or normal, defective) and the origin of the observations' evolution with a low error rate, a reliable diagnosis and a low memory occupation.Keywords: Diagnosis and monitoring, bearings, pattern recognition, learning, dynamic classification, Vibration Analysis, DFSDBSCAN, ESDBSCAN, DDBSCAN

Orientador: Marco Lúcio Bittencourt / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-24T09:08:40Z (GMT). No. of bitstreams: 1 LimaeSilva_RafaelAugustode_M.pdf: 10555723 bytes, checksum: 1d037ebafbabc24e214c06ad76c5f54a (MD5) Previous issue date: 2013 / Resumo: O trabalho descreve o projeto mecânico convencional de uma biela automotiva de motor de combustão interna e apresenta uma metodologia alternativa baseada em métodos de otimização estrutural com o objetivo de reduzir a massa do componente. Para tal, é feita a descrição de todos os parâmetros de projeto assim como a definição de critérios de projeto. Em virtude da criticidade da aplicação selecionada, motor de ciclo Diesel utilizado em caminhões de trabalho pesado com picos de pressão de combustão de até 240 bar, a biela foi projetada sem bucha utilizando-se extensivamente os métodos numéricos. O Método dos Elementos Finitos foi aplicado para cálculo de tensões, deslocamentos, pressões de contato, flambagem, fadiga e para a síntese modal de componentes utilizados na análise dinâmica de multicorpos com mancais elasto-hidrodinâmicos. Dois modelos de fadiga dos materiais foram estudados: o modelo americano baseado no diagrama de Goodman e tensões principais e o modelo alemão baseado no diagrama de Haigh e efeito do gradiente de tensões multiaxiais; dos quais concluiu-se que o modelo americano é suficiente para o projeto da biela ao passo que o modelo alemão traz oportunidades adicionais de redução de massa. A otimização topológica, otimização de forma e análise de sensibilidade permitiram a obtenção de uma biela 210g (3\%) mais leve e com melhor desempenho dos mancais hidrodinâmicos. Finalmente, concluiu-se que o Método da Otimização Topológica apresenta oportunidades interessantes aos projetistas na fase de conceituação de produtos como alternativa aos desenhos convencionais, no entanto, demanda esforço adicional para o atendimento de todos os critérios de projeto do componente / Abstract: The present work consists of the conventional mechanical design description of an internal combustion engine connecting rod and also the proposal of an alternative methodology based on optimization methods with the objective of reducing the component mass. Therefore, it is performed a detailed view of all design parameters as well as the definition of design criteria. Because of the critical application selected, Diesel engine of heavy duty truck with combustion pressure reaching up to 240bar, the connecting rod was designed without bushing and with extensive use of numerical methods. The Finite Element Method was applied to assess stresses, displacements, contact pressures, buckling, fatigue and to perform the Component Modal Synthesis for multi-body dynamics simulation with elasto-hydrodynamic bearings. Two fatigue models were studied: the American model based on Goodman's diagram and principal stresses and the German model based on Haigh's diagram and multiaxial stress gradient effect; from which it was concluded that the American model is enough to design the connecting rod, while the German model presents additional weight reduction opportunities. The topology optimization, shape optimization and sensitivity analysis enabled a 210g (3\%) lighter connecting rod with improved bearings performance. Finally, it was concluded that the Topology Optimization Method presents good opportunities for the design engineers in the conceptual phases of product development with alternatives to the conventional designs. However, additional effort is necessary to fit the concept into all design criteria / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica