Orientador: Valdir Alves Guimarães / Banca: Aelcio Zangrandi / Banca: Marcos Venicius Soares Pereira / Resumo: Atualmente a crescente necessidade de aumento da carga por eixo e do número de passageiros transportados pelos trens, fez com que as ferrovias em todo o mundo iniciassem pesquisas voltadas para o desenvolvimento de novos materiais e processamentos térmicos. O aumento da confiabilidade dos sistemas ferroviários é uma exigência do mercado, o que é definido como sendo a garantia de que não ocorra falhas nos componentes no período entre as inspeções de rotina, ou seja, que um defeito possa ser detectado e reparado antes que atinja um tamanho crítico que leve a ruptura do componente. Por se tratar de um equipamento fundamental nos trens, os eixos ferroviários são alvos de grande parte das recentes pesquisas na área de fadiga, desenvolvimento de novos materiais e segurança dos intervalos de inspeção, uma vez que sua falha, certamente ocasionará um descarrilamento do vagão ou locomotiva. O comportamento em fadiga dos materiais empregados na fabricação de eixos ferroviários vem sendo estudado através de ensaios de propagação de trinca por fadiga, a fim de se obter dados experimentais para definição de intervalos de inspeção. Neste trabalho, foram estudados os aços SAE-1050, comumente utilizado na fabricação de eixos ferroviários, e o SAE- 4130, que recentemente vem sendo empregado para este fim. Estes materiais foram processados por dois diferentes tipos de tratamentos térmicos, sendo um composto por normalização e alívio de tensões, e o outro por normalização, têmpera e revenimento. O comportamento mecânico dos aços foi avaliado através de ensaios de tração, charpy em diversas temperaturas e tenacidade à fratura ( IC K ). O comportamento em fadiga, por sua vez, foi avaliado através de ensaios de propagação de trinca por fadiga, realizados em corpos de prova tração compacto (CT). Para a determinação da influência da razão... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Currently the growing need of increase in axle load and numbers of passengers transported by the trains, prompted the railroads all over the world began researches about the development of new materials and heat treatments. The increase of the reliability for railway systems is a requirement of the market, and can be defined as the warranty that doesn't occur failures in the components between the inspection intervals, in other words, that a defect can be detected and repaired before it reaches a critical size to take the rupture of the component. Axles are one of the most important components in railway vehicle, thus are present in the great part of the recent researches into fatigue, new materials and safe inspection intervals, since its flaw, certainly will cause a derailment of the wagon or locomotive. The fatigue behavior of the employed materials in the production of railway axles has been studied with aid of fatigue crack growth tests, in order to obtain experimental data for definition of inspection intervals. The present work, studied the steels SAE-1050, commonly used in the production of railway axles, and SAE-4130, that recently has been used for this application. These materials were submitted to different heat treatments: normalizing and stress relief, and normalizing, quenching and tempering. The mechanical properties of the steels were evaluated through tensile test, impact test in different temperatures and fracture toughness test. The fatigue behavior was evaluated through of fatigue crack growth tests in compact tension specimens (CT). The influence of the load ratio " R ", on fatigue crack growth was evaluated using the ratio of 0,1 and 0,3. The results showed that the steel SAE-4130, normalized, quenched and tempered, achieved the best mechanical properties and the smallest fatigue crack growth rate, being therefore, the best option as... (Complete abstract click electronic acccess below) / Mestre

Made available in DSpace on 2014-06-11T19:27:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-06-25Bitstream added on 2014-06-13T18:55:38Z : No. of bitstreams: 1 oliveira_lg_me_guara.pdf: 3165585 bytes, checksum: b01429d4faacda4b94f4a66fa205c617 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Atualmente a crescente necessidade de aumento da carga por eixo e do número de passageiros transportados pelos trens, fez com que as ferrovias em todo o mundo iniciassem pesquisas voltadas para o desenvolvimento de novos materiais e processamentos térmicos. O aumento da confiabilidade dos sistemas ferroviários é uma exigência do mercado, o que é definido como sendo a garantia de que não ocorra falhas nos componentes no período entre as inspeções de rotina, ou seja, que um defeito possa ser detectado e reparado antes que atinja um tamanho crítico que leve a ruptura do componente. Por se tratar de um equipamento fundamental nos trens, os eixos ferroviários são alvos de grande parte das recentes pesquisas na área de fadiga, desenvolvimento de novos materiais e segurança dos intervalos de inspeção, uma vez que sua falha, certamente ocasionará um descarrilamento do vagão ou locomotiva. O comportamento em fadiga dos materiais empregados na fabricação de eixos ferroviários vem sendo estudado através de ensaios de propagação de trinca por fadiga, a fim de se obter dados experimentais para definição de intervalos de inspeção. Neste trabalho, foram estudados os aços SAE-1050, comumente utilizado na fabricação de eixos ferroviários, e o SAE- 4130, que recentemente vem sendo empregado para este fim. Estes materiais foram processados por dois diferentes tipos de tratamentos térmicos, sendo um composto por normalização e alívio de tensões, e o outro por normalização, têmpera e revenimento. O comportamento mecânico dos aços foi avaliado através de ensaios de tração, charpy em diversas temperaturas e tenacidade à fratura ( IC K ). O comportamento em fadiga, por sua vez, foi avaliado através de ensaios de propagação de trinca por fadiga, realizados em corpos de prova tração compacto (CT). Para a determinação da influência da razão... / Currently the growing need of increase in axle load and numbers of passengers transported by the trains, prompted the railroads all over the world began researches about the development of new materials and heat treatments. The increase of the reliability for railway systems is a requirement of the market, and can be defined as the warranty that doesn't occur failures in the components between the inspection intervals, in other words, that a defect can be detected and repaired before it reaches a critical size to take the rupture of the component. Axles are one of the most important components in railway vehicle, thus are present in the great part of the recent researches into fatigue, new materials and safe inspection intervals, since its flaw, certainly will cause a derailment of the wagon or locomotive. The fatigue behavior of the employed materials in the production of railway axles has been studied with aid of fatigue crack growth tests, in order to obtain experimental data for definition of inspection intervals. The present work, studied the steels SAE-1050, commonly used in the production of railway axles, and SAE-4130, that recently has been used for this application. These materials were submitted to different heat treatments: normalizing and stress relief, and normalizing, quenching and tempering. The mechanical properties of the steels were evaluated through tensile test, impact test in different temperatures and fracture toughness test. The fatigue behavior was evaluated through of fatigue crack growth tests in compact tension specimens (CT). The influence of the load ratio R , on fatigue crack growth was evaluated using the ratio of 0,1 and 0,3. The results showed that the steel SAE-4130, normalized, quenched and tempered, achieved the best mechanical properties and the smallest fatigue crack growth rate, being therefore, the best option as... (Complete abstract click electronic acccess below)

There is growing interest in the concept of digital twins (DTs) among software engineers and researchers. As an emerging topic, DTs are a promising paradigm to enhance the predictability, safety, and reliability of cyber-physical systems in different domains. Despite the increasing trend, it is continually challenging to decide the best approach to implement DTs. Moreover, to the best of the author's knowledge, it was found that there is a lack of conducted research and no systematic reviews on DTs in the transportation industry, especially in the area of railway systems. Therefore, following the systematic literature review method, this thesis work has identified 363 articles in four digital libraries, of which 60 primary articles were included to address three research questions. The review shows that most of the reviewed articles focus on the railway subarea maintenance and inspection, the DT enabling technology artificial intelligence is the most coupled technology. An in-depth analysis found that most of the articles apply machine learning algorithms and techniques in DTs to detect faults, predict failures, make automated decisions, and monitor health status to optimize railway systems. It was also found that interoperability is the most discussed challenge, where the difficulty is to transmit operational data in real-time and also achieve real-time decision making. Furthermore, the analysis shows several opportunities and advantages of DTs, such as reducing maintenance costs and the positive contribution to a reduction in freight transport by road. Finally, based on the findings of the conducted review, a guideline to support the design of a DT for predictive maintenance in railways in the form of a flowchart is presented and explained.

Conceptual cost estimates play a crucial role on initial project decisions although scope is not finalized and very limited design information is available during early project stages. At these stages, cost estimates are needed by the owner, contractor, designer or the lending organization for several purposes including / determination of feasibility of a project, financial evaluation of a number of alternative projects or establishment of an initial budget. Conceptual cost estimates are not expected to be precise, since project scope is not finalized and very limited design information is available during the pre-design stages of a project. However / a quick, inexpensive and reasonably accurate estimate is needed based on the available information. In this study, conceptual cost estimating models will be developed for urban railway systems using data of projects from Turkey. The accuracy of the models and advantages of the study will be discussed.

De nos jours, le degré de complexité des systèmes de transport notamment ferroviaires est important et grandissant. En effet, les nouvelles technologies et besoins des grandes métropoles contraignent les concepteurs de ces systèmes à toujours intégrer de plus en plus de fonctionnalités. Cette complexité rend obsolète les méthodes de conception traditionnelles qui reposent sur l'expertise d'ingénieurs. La conception du système est définie sur plusieurs documents de spécification, de centaines de pages chacun. Ces derniers comprennent généralement la description des différentes exigences, fonctionnalités et sous-systèmes, ils sont rédigés en langage naturel. Ceci est source d'erreurs et ambigüités lors des différentes phases de conception et de validation sécuritaire. De ce fait, l'ingénierie système basée sur les modèles propose des solutions outillées afin de structurer et spécifier de manière systématique le fonctionnement du système. Dans cette thèse, nous proposons une approche de rétro-ingénierie de ces spécifications système. Cette approche nous permet de définir une méthodologie orientée-scénarios pour la formalisation et analyse de spécifications système. Elle est basée sur le langage de modélisation semi-formel ScOLa (Scénarios Oriented Language) et un modèle d'exécution formel basé sur le langage AltaRica 3.0. Nous proposons, á partir de ScOLa, des techniques contribuant aux analyses de sûreté fonctionnelles du système. Ces techniques permettent de clarifier, structurer et analyser / As of today, the complexity of transportation systems and especially railways is continuously growing. Indeed, new technologies and needs of major metropolitan areas constrain system designers to integrate more and more functionalities. Traditional methods for the design of systems are mainly based on the knowledge of experts. Systems are specified in several documents, of hundreds of pages each. These documents provide a general description of the requirements, functionalities and sub-systems, and are written in a natural language. This is error-prone and source of ambiguities. Model-based systems engineering proposes systematic solutions to structure and specify systems architectures. In this thesis, we propose a reverse engineering approach that is able to capture systems concepts. This leads us to propose ScOLa, a scenario-oriented modeling language for systems specifications with the following features:- A scenario-oriented approach to provide a more contextual view of the system, at several abstraction levels.- A co-construction of the architecture and behavior of the system in the same model.- The use of ScOLa for a seamless integration of system specification and safety analysis. We propose ascenario-oriented methodology for safety analysis, implemented using AltaRica 3.0.

Esta pesquisa tem por objetivo o estudo das relações espaciais potencializadas por uma rede de transporte ferroviário que extrapolasse os limites da Região Metropolitana de São Paulo, mostrando-se como possibilidade para a transformação qualitativa do espaço em direção à sua homogeneização. Para isso, buscou-se construir um conjunto de referências de infraestrutura e serviços ferroviários para o transporte de passageiros a partir dos sistemas europeus, sobretudo o sistema francês. Simultaneamente, foram levantadas e analisadas criticamente as políticas recentes voltadas para implementação desse tipo de infraestrutura no estado de São Paulo, visando estabelecer um panorama sobre os preceitos envolvidos na sua elaboração. Por f im, a p artir d a a valiação e i nterpretação de t odos e sses a spectos, o trabalho propõe dois ensaios: um primeiro de caráter conceitual, buscando estruturar a prática de planejamento para os novos sistemas; e um segundo de caráter propositivo, para a conformação de uma rede ferroviária integrada entre as diferentes escalas hierárquicas traçadas. / This research aims to study the spatial relations as result of a railway transportation network, which extrapolates the limits of the Metropolitan Region o f S ão P aulo, and xplores t he p ossibilities o f a qualitative transformation of the space towards its homogenization. Firstly, the work assemble references concerning infrastructure and railway services in the Western-European context, notably the French railway system. Secondly, the various recent policies of railway system\'s implementation in the state of São Paulo were gathered and analyzed, setting up an overview of their elaborations\' directives. Finally, the work proposes two essays: a) a conceptional one, which set bases for planning practices for new railway transportation systems; and b) a propositional one, which defines an integrated railway network between the different hierarchic scales.

Esta pesquisa tem por objetivo o estudo das relações espaciais potencializadas por uma rede de transporte ferroviário que extrapolasse os limites da Região Metropolitana de São Paulo, mostrando-se como possibilidade para a transformação qualitativa do espaço em direção à sua homogeneização. Para isso, buscou-se construir um conjunto de referências de infraestrutura e serviços ferroviários para o transporte de passageiros a partir dos sistemas europeus, sobretudo o sistema francês. Simultaneamente, foram levantadas e analisadas criticamente as políticas recentes voltadas para implementação desse tipo de infraestrutura no estado de São Paulo, visando estabelecer um panorama sobre os preceitos envolvidos na sua elaboração. Por f im, a p artir d a a valiação e i nterpretação de t odos e sses a spectos, o trabalho propõe dois ensaios: um primeiro de caráter conceitual, buscando estruturar a prática de planejamento para os novos sistemas; e um segundo de caráter propositivo, para a conformação de uma rede ferroviária integrada entre as diferentes escalas hierárquicas traçadas. / This research aims to study the spatial relations as result of a railway transportation network, which extrapolates the limits of the Metropolitan Region o f S ão P aulo, and xplores t he p ossibilities o f a qualitative transformation of the space towards its homogenization. Firstly, the work assemble references concerning infrastructure and railway services in the Western-European context, notably the French railway system. Secondly, the various recent policies of railway system\'s implementation in the state of São Paulo were gathered and analyzed, setting up an overview of their elaborations\' directives. Finally, the work proposes two essays: a) a conceptional one, which set bases for planning practices for new railway transportation systems; and b) a propositional one, which defines an integrated railway network between the different hierarchic scales.

Im Rahmen der Arbeit wird der Begriff Sicherheit aus verschiedenen Blickwinkeln beleuchtet, Randbedingungen aus Theorie und Praxis zielorientiert strukturiert und ein Vorschlag für eine Integration betrieblicher Aspekte in Sicherheitsanalysen dargelegt. Dazu werden zunächst die normativ verankerten Lebenszyklusphasen des Bahnsystems und die darin festgelegten Verantwortlichkeiten vorgestellt. Darauf aufbauend erfolgt die beispielhafte Beschreibung einer neuen Analysemethode in Verfügbarkeits-Sicherheits-Diagrammen für betriebliche Szenarien des Bahnsystems. Die Arbeit endet mit der Vorstellung des Modells zur ganzheitlichen Sicherheitsbetrachtung des Bahnsystems, welches die zuvor gewonnenen Erkenntnisse integriert und die Grundlage für das Zulassungsverfahren von Bahnanlagen mit betrieblichem Sicherheitsnachweis legt. / This thesis deals with the detailed analysis of the term safety from different points of view. The main target of the document is the integration of operational aspects within technical solutions for railway systems. Operational use-cases have been analyzed using the availability-safety-diagram. The document concludes with the introduction of a model for holistic safety-related consideration of railway systems.

Thesis (MDF (Development Finance))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Historically, passenger railway service has played a vital role in the socio-economic activities in Zambia. Its capacity to transport a great mass of people at a low cost has had a profound appeal, especially amongst the low-income segment of society, in this country. This research report sought to examine the concessioning process for Railway Systems of Zambia Limited in relation to international best practice, to examine the extent of passenger train delays in relation to acceptable international standards and to recommend policy and remedial measures. A review of relevant literature on public-private partnerships in infrastructure projects including passenger railway concessioning and passenger train punctuality, in relation to international standards was undertaken. The research covered the period 2002 to 2007, with an average sample size of 11% (144 passenger train trips out of 1 344). Data from timetables and train logbooks, relating to arriving and departing trains, enabled the computation of the extent of delays or punctuality of trains. While international best practice requires passenger trains to operate at between 90% and 95% punctuality rate within 10 to 15 minutes of the timetable, Railway Systems of Zambia’s passenger trains, for the period 2004 to 2007, recorded between 92% and 100% delay rates for trains expected to arrive within 10 and 15 minutes of the timetable. The maximum delay for the arrival of a train in 2005 was 1 422 minutes (23 hours 42 minutes). Therefore, this research report recommends the formulation of a policy framework, a legal and regulatory framework and the establishment of an institutional arrangement that will be responsible for public-private partnerships projects in Zambia. In addition, increased investment in the railway infrastructure by the concessionaire is recommended in order for trains to increase speed and therefore improve their punctuality. / AFRIKAANSE OPSOMMING: Histories het spoorweg passasiersdienste nog altyd ‘n deurslaggewende rol in die sosio-ekonomiese aktiwiteite van Zambië gespeel. Die kapasiteit om groot massas mense teen ‘n lae koste te vervoer, was baie aanloklik in hierdie land, veral vir die lae-inkomstegroep van die gemeenskap. Hierdie navorsingsverslag poog om die konsessioneringsproses van die Spoorwegsisteem van Zambië Beperk, in verhouding tot internasionale toppraktyke, te ondersoek; om die omvang van passasierstreinvertragings in verhouding tot internasionaal aanvaarbare standaarde te ondersoek en ook om beleid en herstellende veranderings aan die hand te doen. ‘n Verslag van toepaslike letterkunde oor publiek-private vennootskappe in infrastruktuurprojekte, wat spoorweg passassiers konsessionering en stiptelikheid van passasierstreine vergelyk met internasionale standaarde, is onderneem. Die navorsing dek die periode van 2002 tot 2007, met ‘n gemiddelde steekproef grootte van 11% (144 passasiers treinritte uit ‘n total van 1 344). Data van treinroosters en treinjoernale, wat verband hou met die aankoms en vertrek van treine, het die berekening van die omvang van vertragings of stiptelikheid van die treine moontlik gemaak. Terwyl internasionale toppraktyke vereis dat passasierstreine binne ‘n 90% en 95% stiptelikheidskoers van 10 tot 15 minute, volgens die reisrooster, moet funksioneer, het die passasierstreine van Zambië vir die periode van 2004 tot 2007, ‘n vertragingskoers van tussen 92% en 100% vir treine wat binne 10 tot 15 minute van die reisrooster se tye moes aankom, aangeteken. Die maksimum vertraging op die aankomstyd van ‘n trein was in 2005 teen 1 422 minutes (23 hours 42 minutes). Derhalwe beveel hierdie navorsingsverslag aan dat ‘n beleidsraamwerk en ‘n wets- en reguleringsraamwerk geformuleer moet word, asook die instelling van ‘n genootskapsooreenkoms, wat verantwoordelik sal wees vir die publiek-private vennootskapprojekte in Zambië. Ter aanvulling word ‘n verhoogde belegging, deur die konsessionaris, in die spoorweg infrastruktuur aanbeveel sodat treine vinniger kan ry en dus meer stiptelik sal wees.

<p>This thesis deals with the electromagnetic compatibility (EMC) problems of distributed electrical networks, especially that caused by lightning to electrified railway. Lightning transients were found to damage important devices that control train movements, causing traffic stoppage and delays. This thesis attempts to develop computational models for identification of parameters influencing the coupling phenomena between those devices and lightning. Some supporting experimental investigations are also carried out. This thesis forms the groundwork on the subject of lightning interaction with the electrified railway networks.</p><p>Lightning induces transient overvoltages in railway conductor systems such as tracks, overhead wires, and underground cables, either due to direct lightning strike to the system or due to the coupling of electromagnetic fields from remote strikes. Models based on multiconductor transmission line theory were developed for calculating the induced voltages and currents. A transmission line return stroke model, that can predict the remote electromagnetic fields comparable to experimental observations, is also developed. </p><p>Earlier works on modeling earth return impedances for transient studies in power distribution systems are not readily applicable for railways for lightning transients, in cases of low earth conductivities found in Sweden and for large variation in conductor heights. For the wires above ground, the ground impedance models were modified for wide range of frequencies, soil conductivities and wide spread of conductor heights. Influences of pole insulator flashovers, pole-footing soil ionizations and interconnections between the conductors on the lightning surge propagation are studied. Wave propagation in buried shielded and unshielded cables with ground return is studied. Simplified, valid and computationally efficient ground impedance expressions for buried and on-ground wires are proposed. A model for the coupling phenomena (transfer impedance) through multiple cable shields with multiconductor core is also proposed. Besides, experimental studies on lightning induced transients entering a railway technical house, failure modes of relay and rectifier units used in the train position/signaling applications for lightning transients are performed. A high frequency circuit model for the booster transformer for lightning interaction studies is developed. The simulation models are being converted to user-friendly software for the practicing engineers of the railway industry.</p>