This thesis deals with stress analysis of tandem platform trailer TVL10. The first part is devoted to description of trailers and their parts. The second part presents and evaluates the results of measuring acceleration and vibration of the trailer, and it describes the concrete chassis of a tandem trailer. There is included an analysis of the existing structure, design modifications and stress calculation and evaluation of newly designed chassis structure. The thesis is developed in cooperation with PANAV, a.s.

Numerische Methode zur Bestimmung der Fahrwerkskonfiguration aus Baukastenkomponenten

No description available.

The feasibility of replacing currently widely used sandwich construction with helically stiffened construction for a Formula racing car structural shell is studied. The torsional deformation behavior of circular and square cross-section shells is analyzed as an approximation to the real car structure. Shells with different sandwich and helically stiffened configurations are analyzed with finite elements. For closed square and circular cross-section shells, the highest torsional stiffness is obtained with helical stiffening. For circular cross-section shells with the cockpit cutout and reinforcements usually present in real racing car structural shells, ±4S' helically stiffened shells are 200% stiffer in torsion than sandwich shells. For square cross-section shells, the torsional stiffness improvement obtained with the helical stiffening is only 27%. The cross-sectional shape of the shell, cockpit opening, and different type of reinforcements (present in a real car structure) affects the selection of the best stiffening for torsional stiffness. The role of the terms of the stiffness matrix of the helically stiffened configuration in the torsional behavior of the shells is studied. The 0/90 waffle stiffening is more efficient than the helical stiffening for the square cross-section shells with the cutout and reinforcements. In the case of circular cross-section shells, the 0/90 waffle stiffening yields approximately the same results than the helical stiffening. The skin-stiffener configuration for maximum torsional stiffness depends on the crosssectional shape of the shell. The advantages of the ±45° helical stiffening over the sandwich construction depend on the cross-sectional shape of the shell and on the way the cutout region is reinforced. / Master of Science

Werkstoff- und Prozessgrenzen beschränken unter Beachtung ökonomischer und ökologischer Aspekte den Leichtbau gegossener Fahrwerk-Komponenten aus Al-Si-Legierungen. Zunächst werden Bauteilgewicht und Wärmebehandlungsprozess als beeinflussbare Hauptbeitragsleister für Emissionen im Herstellprozess identifiziert. Zu deren Verringerung werden abhängig von der Belastungsart mögliche Mindestwandstärken abgeleitet, die für den Kokillenguss um 35 % reduziert werden. Dies gelingt durch Einsatz neuartiger, das Formfüllverhalten verbessernder Oberflächenstrukturierungen von Gießwerkzeugen bei Einhaltung von Konstruktionsregeln. Die Gesamtprozesszeit der Wärmebehandlung kann bei gleichbleibenden mechanischen Eigenschaften um 40 % verkürzt werden. Dabei erfolgt die Charakterisierung des Werkstoff- und Bauteilverhaltens unter dynamischer Belastung bei Parametervariation, da keine Korrelation zu den statischen mechanischen Kennwerten vorliegt.

Os ruídos, vibrações e asperezas de rodagem veicular (do acrônimo em inglês Road NVH), presentes de 20 Hz até 1000 Hz aproximadamente, originam-se das vibrações e propagações acústicas dos pneus ao interagir com as superfícies. Nestas fontes de ruído, ambas as vias de contribuições estruturais e aéreas, são relevantes para o refinamento veicular. Constantes são os esforços para estudar o veículo como um conjunto de caminhos de transferência entre a dinâmica dos pneus até o conforto dos passageiros. Sendo assim, o tratamento dos mecanismos que geram e propagam o ruído e vibração à cabine está avançando, graças aos testes e análises sistemáticas, fundamentadas na teoria de Análises dos Caminhos de Transferências de energia (TPA do inglês transfer path analysis). O objetivo deste trabalho é apresentar um estudo de um caso de Road NVH utilizando o TPA em veículo protótipo. Neste tema, é investigado o nível de ruído de rodagem em torno de 180 Hz, semelhante ao efeito de roncar (rumble, na expressão em inglês). Este ruído permanece presente no protótipo, em diversos tipos de pista e velocidades, porém em apenas um modelo de pneu (batizado de modelo \"A\"), entre os diversos testados. Das avaliações subjetivas prévias, defini-se que o foco das investigações são as contribuições estruturais da suspensão dianteira. Usando o TPA para demonstrar os caminhos críticos na formação do rumble, aplicou-se o método da matriz inversa para o calculo das forcas, considerando os seguintes pontos: buchas do braço de controle do A-Arm e de ligação da carroceria com a parte superior da suspensão dianteira (fig. 4.6 - tipo Mc Pherson). Foram obtidas experimentalmente as vibrações dos lados ativos e passivos destes pontos, nas condições de rolagem e as funções de resposta vibracionais e acústica do ponto, no laboratório. Após a correlação do ruído interno calculado com o medido, concluiu-se que o rumble deste caso foi gerado pela baixa eficiência de isolação das vibrações radiais nas buchas anteriores e pela força lateral do pneu \"A\". Por fim, propostas de bucha e pneu são apresentadas em termos das novas forças e respostas acústicas transmitidas, para minimizar o rumble. / The road noise, vibration and harshness (Road NVH) present from 20 Hz to 1000 Hz approximately, begins from the tires vibration and acoustic propagation and their interactions with the road surfaces. In these noise sources, both structural-borne and air-borne noise contributions are relevant to vehicle refinement. The constant efforts to study the vehicle as a set of transfer paths from tires dynamic behavior to passenger comfort to the final passenger comfort perception. Thus the treatment of generation and propagation mechanisms, have being forward thanks to the systematic tests and proceedings based on the transfer path analysis theory (TPA). The purpose of this work is to present a case study of Road NVH, using TPA in prototype vehicle. On this theme, it is investigated a higher noise level around 180 Hz, on the rumble narrow band. This noise remains in the prototype during several types of tracks and speeds conditions, whenever only a tire model, named as sample A, is used, despites all tires tested. From the previous subjective evaluation, the focus of the investigation is defined to be structure-borne of the front suspension. Using TPA to demonstrate the critical paths to rumble, it was applied the matrix inversion method to force calculation, considering the follow points: A-Arm type lower control arm bushings and top mounts of front suspension (picture 4.6 - Mc Pherson type). The vibration in the active and passive side of these points during test conditions and the FRFs driving points and body sensitivity for a target microphone were obtained experimentally. After correlation between internal road noise calculated and the measured, it was concluded the Rumble of this case had been formed by low radial vibration isolation of the front bushings and due lateral forces of tire A. At last, the bushing and tire proposals are presented in terms of new transmitted forces and acoustical responses, to minimize the rumble.

Cette thèse s'inscrit dans le cadre de la conception des systèmes mécatroniques. Les travaux se positionnent dans les premières phases du cycle de conception, là où les principaux efforts méthodologiques sont à mener pour améliorer la qualité et la fonctionnalité des produits, et reposent sur le prototypage virtuel (modélisation et simulation). Une approche méthodologique envisageable est de reformuler le problème de conception sous une forme inverse, pour directement utiliser les spécifications du cahier des charges, usuellement exprimées sur les sorties, pour calculer les inconnues du problème. Dans ce contexte, le laboratoire Ampère développe une méthodologie de conception et dimensionnement, basée sur l'inversion de modèle, utilisant le formalisme bond graph, pour proposer une démarche reposant sur des critères dynamiques et énergétiques, et dont la principale originalité est sa phase d'analyse structurelle, permettant une hiérarchisation d’analyse suivant différents niveaux de la structure physique du modèle (topologie, phénoménologie, paramétrage). L'objectif est de contribuer au développement de cette méthodologie, en l’étendant aux modèles appartenant à la classe des systèmes singuliers, porté par la velléité de décliner la démarche à la conception fonctionnelle du châssis automobile et de ses sous-systèmes, comportant un certain nombre d'abstractions de modélisation et d'idéalisations. Cette déclinaison est proposée, d’une part, au niveau de la structure du modèle et, d’autre part, à un niveau considérant sa phénoménologie et ses lois de comportement. Elle requiert la mise en place préalable d'un référentiel algébrique, essentiellement issu de travaux sur la commande des systèmes, pour constituer une base de validation des extensions graphiques (digraphe et bond graph) proposées. En plus de la généralisation qu'ils constituent à la classe des modèles singuliers, les présents travaux proposent une uniformisation des précédentes approches de la méthodologie, originellement appliquées respectivement aux modèles directs et aux modèles inverses, de sorte qu'il n'est à présent plus nécessaire de les différencier. / The context of this PhD thesis is the modeling and design of mechatronic systems. The study is positioned in the early design stage of the conception cycle (V-Cycle), where the main efforts have to be produced in terms of methodology, to enhance the quality and the functionality of the products, and based on virtual prototyping (modeling and simulation). One of the possible methodology is to reformulate the design problem as an inverse problem, in order to directly use the design specification of the product, usually given in terms of the system outputs, and then solve the design problem. In this context, the Ampere laboratory of INSA Lyon has developed a conception and design methodology, based on inverse approach and using the bond graph formalism, to propose a step-by-step method based on dynamic and energetic criteria, with a structural analysis phase that allows hierarchical analysis steps, depending on the structural physical layout of the model (topological, phenomenological, parameter set). The aim of the present works is to contribute to the development of this methodology, by enhancing it to the class of descriptor systems. This choice is led by the aim to apply the methodology in the context of chassis design and vehicle dynamics, where, among other, multi-body models represented as a differential-algebraic equation (DAE) system could occur. The contributions are proposed at the level of the topology of the model, as well as at the level of the phenomenological / behavioral aspects. A preliminary step is to enhance the existing algebraic framework to support graphical extension (in term of digraph and bond graph). The overall methodological extensions allow, firstly, a generalization of the approach to the class of descriptor systems, and, secondly, to reach a standardization of the procedures, previously dedicated to direct or inverse models, so as no mandatory differences between those models have to be done anymore.

[pt] O desenvolvimento de um motor de quatro tempos, de ignição por centelha, com injeção direta de combustível dentro da câmara de combustão foi uma iniciativa importante para o mercado automobilístico mundial. O potencial termodinâmico deste tipo de motor e sua notória melhoria na economia de combustível têm feito com que a tecnologia seja foco de um grande número de projetos de pesquisa, com o objetivo de entender, desenvolver e aperfeiçoar o sistema de injeção direta de combustível. No entanto, para atender aos novos limites de emissões estabelecidas pela especificação EURO 5, foi necessária uma reavaliação do projeto da geometria do injetor, o que ocasionou no desenvolvimento de um novo componente com um maior número de furos e com uma redução do diâmetro dos mesmos (injetor multifuros). Essa alteração no projeto visa garantir uma melhor pulverização, otimização da relação ar/combustível e, consequentemente, um melhor processo de queima na câmara de combustão, atendendo dessa forma os limites de emissões estabelecidos pela diretriz normativa vigente. Os processos de preparação da mistura, injeção, vaporização e controle do escoamento de ar dentro do cilindro têm sido as principais fontes de publicações de periódicos que estudam o sistema de injeção direta. O presente trabalho, por sua vez, tem por finalidade avaliar a formação de depósitos de compostos inorgânicos nos injetores, provenientes da utilização de combustíveis formulados com diferentes teores de sulfato. O motor utilizado para execução dos testes foi o EP6CDT da PSA Peugeot Citroen. No estudo foram realizados ensaios em bancada de testes e em veículos (estrada e dinamômetro). Outros veículos com a mesma tecnologia, disponíveis no mercado brasileiro, também foram testados. As variáveis avaliadas durante o projeto foram: a composição química de diferentes combustíveis, fator de correção do tempo de injeção (FRA) e a vazão através dos bicos injetores no decorrer dos testes. Os estudos indicaram que a mudança na geometria dos injetores, somada a composição das gasolinas nacionais testadas, originou a formação dos depósitos que será discutida ao longo deste trabalho. / [en] The development of a four-stroke engine, spark ignition, with direct injection of fuel into the combustion chamber was an important initiative for the global automotive market. The thermodynamic potential of this type of engine and its significant improvement in fuel economy have meant this technology as focus of a large number of research projects, with the objective to understand, develop and improve the system of direct fuel injection. However, to meet new emission limits set by Euro 5 specification, it was necessary to reevaluate the geometry design of the injector, which resulted in the development of a new component with a larger number of holes and with a diameter reduction (multi-holes injector). This change in the project aims to ensure a better spray, optimizing air / fuel ratio and, consequently, a better process of combustion inside the combustion chamber, satisfying the emission limits established by the applicable norms. The processes for preparing the mixture, injection, atomization and air flow control inside the cylinder have been the main source of periodic publications that study the direct injection system. Therefore, this paper purpose is to evaluate the formation of inorganic deposits in the injectors using fuels formulated with different amounts of sulfate. The engine used for running the tests was the EP6CDT of PSA Peugeot Citroen. For this study one has performed tests on test bench and in vehicles (road and dynamometer). Other vehicles, with the same technology available in Brazil, were also tested. The variables evaluated during the project were: the chemical composition of different fuels, the correction factor from the injection time (FRA) and flow through the injectors during the tests. This study has indicated that the injector geometry modification, coupled with tested compositions of gasoline, resulted in the formation of deposits that will be discussed throughout this work.

Os ruídos, vibrações e asperezas de rodagem veicular (do acrônimo em inglês Road NVH), presentes de 20 Hz até 1000 Hz aproximadamente, originam-se das vibrações e propagações acústicas dos pneus ao interagir com as superfícies. Nestas fontes de ruído, ambas as vias de contribuições estruturais e aéreas, são relevantes para o refinamento veicular. Constantes são os esforços para estudar o veículo como um conjunto de caminhos de transferência entre a dinâmica dos pneus até o conforto dos passageiros. Sendo assim, o tratamento dos mecanismos que geram e propagam o ruído e vibração à cabine está avançando, graças aos testes e análises sistemáticas, fundamentadas na teoria de Análises dos Caminhos de Transferências de energia (TPA do inglês transfer path analysis). O objetivo deste trabalho é apresentar um estudo de um caso de Road NVH utilizando o TPA em veículo protótipo. Neste tema, é investigado o nível de ruído de rodagem em torno de 180 Hz, semelhante ao efeito de roncar (rumble, na expressão em inglês). Este ruído permanece presente no protótipo, em diversos tipos de pista e velocidades, porém em apenas um modelo de pneu (batizado de modelo \"A\"), entre os diversos testados. Das avaliações subjetivas prévias, defini-se que o foco das investigações são as contribuições estruturais da suspensão dianteira. Usando o TPA para demonstrar os caminhos críticos na formação do rumble, aplicou-se o método da matriz inversa para o calculo das forcas, considerando os seguintes pontos: buchas do braço de controle do A-Arm e de ligação da carroceria com a parte superior da suspensão dianteira (fig. 4.6 - tipo Mc Pherson). Foram obtidas experimentalmente as vibrações dos lados ativos e passivos destes pontos, nas condições de rolagem e as funções de resposta vibracionais e acústica do ponto, no laboratório. Após a correlação do ruído interno calculado com o medido, concluiu-se que o rumble deste caso foi gerado pela baixa eficiência de isolação das vibrações radiais nas buchas anteriores e pela força lateral do pneu \"A\". Por fim, propostas de bucha e pneu são apresentadas em termos das novas forças e respostas acústicas transmitidas, para minimizar o rumble. / The road noise, vibration and harshness (Road NVH) present from 20 Hz to 1000 Hz approximately, begins from the tires vibration and acoustic propagation and their interactions with the road surfaces. In these noise sources, both structural-borne and air-borne noise contributions are relevant to vehicle refinement. The constant efforts to study the vehicle as a set of transfer paths from tires dynamic behavior to passenger comfort to the final passenger comfort perception. Thus the treatment of generation and propagation mechanisms, have being forward thanks to the systematic tests and proceedings based on the transfer path analysis theory (TPA). The purpose of this work is to present a case study of Road NVH, using TPA in prototype vehicle. On this theme, it is investigated a higher noise level around 180 Hz, on the rumble narrow band. This noise remains in the prototype during several types of tracks and speeds conditions, whenever only a tire model, named as sample A, is used, despites all tires tested. From the previous subjective evaluation, the focus of the investigation is defined to be structure-borne of the front suspension. Using TPA to demonstrate the critical paths to rumble, it was applied the matrix inversion method to force calculation, considering the follow points: A-Arm type lower control arm bushings and top mounts of front suspension (picture 4.6 - Mc Pherson type). The vibration in the active and passive side of these points during test conditions and the FRFs driving points and body sensitivity for a target microphone were obtained experimentally. After correlation between internal road noise calculated and the measured, it was concluded the Rumble of this case had been formed by low radial vibration isolation of the front bushings and due lateral forces of tire A. At last, the bushing and tire proposals are presented in terms of new transmitted forces and acoustical responses, to minimize the rumble.

The Formula SAE is a student based competition organised by SAE International where engineering students from a university design, develop and test a formula-style race car prototype to compete against other universities. The competition car needs to satisfy the competition rules set out by the organisers. The competition strives to stimulate original, creative problem solving together with innovative engineering design practices. In any race environment, the primary goal is always to be as competitive as possible. Due to the competitive nature of motor sport, vehicle components need to withstand various and severe stresses. The components of a race car vehicle are responsible for the vehicle’s handling characteristics and reliability. The chassis is a crucial and integral component of a Formula SAE competition car, primarily responsible for the vehicle’s performance characteristics. The chassis is the structural component that accommodates all the other components. A Formula SAE chassis is a structure that requires high torsional stiffness, low weight as well as the necessary strength properties. In this study, multiple Formula SAE chassis were designed and developed using computer aided design software. Each concept’s torsional stiffness, weight and strength properties were tested using finite element analysis software. The different concepts consisted of different design techniques and applications. All the concepts were analysed and assessed, leading to the identification of an acceptable prototype. The prototype was manufactured for experimental tests. The designed chassis complied with the Formula SAE rules and regulations. The weight, torsional stiffness and strength characteristics of the designed chassis frame were also favourable compared to accepted standards for Formula SAE chassis frames. The manufactured chassis was prepared for experimental tests in order to validate the simulation results produced by the finite element analysis. The torsional stiffness, weight and strength were experimentally determined and the results were compared with the corresponding simulations results. The comparison of the experimental and simulated results enabled the validation of the finite element analysis software. The study draws conclusions about the use of computer aided design and finite element analysis software as a design tool for the development of a Formula SAE chassis. Closure about the study is provided with general conclusions, recommendations and research possibilities for future studies. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014