A busca por estruturas mais esbeltas, economicamente viáveis e esteticamente atraentes impulsionou a evolução e inovação no ramo de pontes. A protensão, tanto interna quanto externa, tem sido usada em larga escala e devido à sua eficiência, diversas técnicas foram desenvolvidas e utilizadas, como os estais. A ponte extradorso é uma estrutura que mantém características das pontes de viga reta construídas por balanços sucessivos, assim como de pontes estaiadas. A ponte com protensão no extradorso é uma estrutura recente e inovadora, que ainda é pouco utilizada no Brasil. O conceito desenvolvido em 1988 foi construído pela primeira vez em 1994 no Japão. Por serem estruturas com extensos vãos e que podem sofrer vibração excessiva, quando submetidas a carregamentos dinâmicos de grande intensidade, como os carregamentos móveis, é importante analisar o comportamento destas. A dinâmica das estruturas engloba a determinação das frequências naturais e dos modos de vibração naturais da estrutura, assim como os possíveis deslocamentos, esforços internos, velocidade e acelerações. Os modelos computacionais, usando o princípio do método dos elementos finitos, quando devidamente utilizados, podem representar valores muito próximos à realidade da estrutura em serviço. Este trabalho tem a intenção de analisar o comportamento dinâmico da ponte situada na TO-010, entre Miracema e Lajeado, inaugurada em 2011, quando submetida a diferentes carregamentos móveis e com diferentes velocidades, comparando-os com a análise estática. / Searching for more slender structures, economically viable and aesthetically appealing drove and innovation in the bridges. Prestressing, both internal and external, has been used on a large scale due to its efficiency; several techniques have been developed and used, as the stays. The extradosed bridge is a structure that retains characteristics of straight girder bridges built by successive balances, as well as cable-stayed bridge. Prestressing extradosed is an innovative new structure, which is not widely used in Brazil. The concept developed in 1988 was first constructed in 1994 in Japan. Because they are structures with long spans and can suffer excessive vibration when subjected to dynamic loading of high intensity such as live loads, it is important to analyze their behavior. The dynamic of structures includes determining the frequency and mode of natural vibration of the structure, as well as the possible displacements and internal forces. Computer models, using the principle of the finite element method, when properly calibrated, can represent values close to the reality of the structure in service. This paper intends to analyze the dynamic behavior of the bridge located in the TO-010, between Miracema and Lajeado, inaugurated in 2011, when subjected to different moving load, and moving at different speed, comparing them with the static analysis. / 5000

A busca por estruturas mais esbeltas, economicamente viáveis e esteticamente atraentes impulsionou a evolução e inovação no ramo de pontes. A protensão, tanto interna quanto externa, tem sido usada em larga escala e devido à sua eficiência, diversas técnicas foram desenvolvidas e utilizadas, como os estais. A ponte extradorso é uma estrutura que mantém características das pontes de viga reta construídas por balanços sucessivos, assim como de pontes estaiadas. A ponte com protensão no extradorso é uma estrutura recente e inovadora, que ainda é pouco utilizada no Brasil. O conceito desenvolvido em 1988 foi construído pela primeira vez em 1994 no Japão. Por serem estruturas com extensos vãos e que podem sofrer vibração excessiva, quando submetidas a carregamentos dinâmicos de grande intensidade, como os carregamentos móveis, é importante analisar o comportamento destas. A dinâmica das estruturas engloba a determinação das frequências naturais e dos modos de vibração naturais da estrutura, assim como os possíveis deslocamentos, esforços internos, velocidade e acelerações. Os modelos computacionais, usando o princípio do método dos elementos finitos, quando devidamente utilizados, podem representar valores muito próximos à realidade da estrutura em serviço. Este trabalho tem a intenção de analisar o comportamento dinâmico da ponte situada na TO-010, entre Miracema e Lajeado, inaugurada em 2011, quando submetida a diferentes carregamentos móveis e com diferentes velocidades, comparando-os com a análise estática. / Searching for more slender structures, economically viable and aesthetically appealing drove and innovation in the bridges. Prestressing, both internal and external, has been used on a large scale due to its efficiency; several techniques have been developed and used, as the stays. The extradosed bridge is a structure that retains characteristics of straight girder bridges built by successive balances, as well as cable-stayed bridge. Prestressing extradosed is an innovative new structure, which is not widely used in Brazil. The concept developed in 1988 was first constructed in 1994 in Japan. Because they are structures with long spans and can suffer excessive vibration when subjected to dynamic loading of high intensity such as live loads, it is important to analyze their behavior. The dynamic of structures includes determining the frequency and mode of natural vibration of the structure, as well as the possible displacements and internal forces. Computer models, using the principle of the finite element method, when properly calibrated, can represent values close to the reality of the structure in service. This paper intends to analyze the dynamic behavior of the bridge located in the TO-010, between Miracema and Lajeado, inaugurated in 2011, when subjected to different moving load, and moving at different speed, comparing them with the static analysis. / 5000

SMF är viktiga för den svenska finansmarknaden då de utgör 99 % av de totala företagen i landet. Dessa företag anses vara mycket bankberoende och mer känsliga för externa ekonomiska fluktuationer än större företag. Oavsett hur den globala ekonomin ser ut så måste företag kunna finansiera sin verksamhet med kapital. Kapitalstruktur är ett omdebatteratforskningsämne som saknar en generell teori för majoriteten av företag, vilket skapar en stor forskningsyta för ämnet. Sverige har en omfattande export med en finansmarknad som är väl integrerad med den globala ekonomin. Den svenska exporten föll avsevärt under finanskrisen 2008 vilket ger en indikation om att exportberoende företag drabbades hårt av finanskrisen,inte minst SMF. Ett minskat kreditutbud i kombination med en finansiell kris kan förmodas ha gett upphov till finansieringsproblem för dessa företag.Syftet med uppsatsen är att undersöka sambandet mellan företagsspecifika faktorer och kapitalstrukturen i metallbranschens företag, där den primära aspekten för studien är att utreda hur företagens kapitalstruktur förändrades i samband med finanskrisen 2008.Studien utgår från en kvantitativ metod med en deduktiv ansats. För att besvara studiens syfte och forskningsfrågor genomförs regressions-, korrelations- och deskriptiva analyser för att kunna analysera sambandet mellan de utvalda beroende variablerna och de oberoende variablerna. Flertalet regressionsanalyser och ANOVA-tester genomförs för att kunnaundersöka om en signifikant skillnad i företagens kapitalstruktur föreligger mellan tidsperioderna. Resultatet visar att det finns en signifikant skillnad i de utvalda företagens kapitalstruktur mellan perioden under finanskrisen och efter krisen. De kortfristiga skulderna stod för den största förändringen som minskade markant under krisperioden i metallbranschens företag. De oberoende variablerna som påvisar det största sambandet förskuldsättningsgraden är lönsamhet och materiella anläggningstillgångar. Studien finner ett negativt samband mellan lönsamhet och samtliga skuldsättningsgrader, samt ett negativt samband mellan materiella anläggningstillgångar och den långfristiga skuldsättningsgraden.Ett motsatt förhållande observeras dock för den kortfristiga skuldsättningsgraden som enligt resultatet har ett negativt samband med materiella anläggningstillgångar. Studien finner även ett mindre positivt samband mellan tillväxt och samtliga skuldsättningsgrader. / SMEs have become significantly important for the Swedish economy since they account for 99 % of all the businesses in Sweden. These firms rely heavily on bank credits and are more sensitive to external economic fluctuations relative to larger firms. Regardless of the events in the global economy, firms must be able to finance its operations with capital. Previousresearch on capital structure indicates a difficulty to find a general theory that can be applied for the majority of firms, which provides more scope for further research in the subject. Sweden is a very export-dependent country and is highly integrated into the global economy. The Swedish export decreased substantially due to the financial crisis 2008, which indicates that export-dependent firms was suffering during the given time period. The combination of a decline in credit supply and a financial crisis gives us the assumption of financial problems in these firms. The purpose of this study is to examine whether or not the recent financial crisis had an impact capital structure in the iron- and steel industry. The importance of different determinants that affects the capital structure will also be reviewed.A quantitative method with a deductive approach will be used for the study. To fulfil the purpose of the study, regression-, correlation- and descriptive analysis will be performed in order to analyse the relation between the dependent variables and the independent variables. Several regression analysis and ANOVA-test will be carried out in order to determine whether or not there is a significant difference in the firms capital structure between the two time periods. The study finds a significant change in capital structure between the two time periods. The short-term debt ratio accounted for the greatest change and decreased substantially during the financial crisis. In addition, the result suggests that profitability and tangible assets are the most important determinants explaining the capital structure of Swedish SMEs in the iron- and steel industry. The study finds a negative relation betweenprofitability and leverage, and a negative relation between tangible assets and short-term debt. Contradictory, a positive relation can be observed between tangible assets and long-term debt. Additionally, a small positive relation can be found between growth and leverage during both time periods. / <p>Betyg B, 170612</p>

Cette thèse a pour objectifs de développer une modélisation aussi fine que possible des structures aciers et mixtes acier-béton sous sollicitations cycliques avec prise en compte d'une part du comportement des assemblages et d'autre part des non-linéarités géométriques et du contact à l'interface acier-béton. Notre attention porte en particulier sur l'assemblage de type poutre acier/mixte sur poteau métallique par platine d'extrémité boulonnée. L'objectif étant de proposer un modèle «élément fini» d'assemblage qui reproduit aussi fidèlement que possible le comportement cyclique de ce dernier pour ensuite l'assembler à un élément fini de poutre non-linéaire acier ou mixte avec prise en compte, pour ce dernier, du soulèvement à l'interface. Le travail se compose de 3 parties distinctes. Un premier modèle qui se base sur la méthode des composantes a été développé ayant pour objectif de suivre la déformation de chaque composante au cours des cycles et de prendre en compte les non-linéarités induites par la séparation entre la platine d'extrémité et la semelle du poteau auquel elle est boulonnée. Ce modèle type composantes, a été développé pour une rangée de boulons. Dans le cas le plus fréquent, de deux rangées de boulons, une résistance de groupe (en plus des résistances individuelles de chacune des rangées) est susceptible de se développer. Pour rendre compte de ce phénomène, nous avons implanté le modèle proposé par Cerfontaine qui repose sur la définition d'une surface de charge et une règle d'écoulement associée pour déterminer les allongements des ressorts équivalents. Seul le cas de plasticité parfaite est considéré. Il est mis en évidence que l'influence de l'effet de groupe s'avère non négligeable sur le comportement post-élastique de l'assemblage et donc de la structure. Dans une seconde phase, nous proposons un modèle de poutre métallique classique en grands déplacements (approche co-rotationnelle) avec rotules généralisées aux extrémités. Nous faisons l'hypothèse que les déformations plastiques sont concentrées aux rotules dont le comportement plastique est contrôlé par une surface de charge asymétrique (anisotrope) qui peut prendre différentes formes selon la valeur donnée à un facteur q dit « facteur de forme». Chacune de ces rotules plastiques comprend un ressort longitudinal pour l'effort normal Net un ressort spiral pour le moment fléchissant M. L'interaction (M-N) entre ces deux efforts dans le domaine plastique est régie par le critère de plasticité. Le modèle de rotule plastique généralisé proposé permet de rendre compte de l'adoucissement cyclique, de la ductilité et du « pinching effect ».Nous montrons aux travers de plusieurs exemples la pertinence mais également les limites d'une telle approche. Dans une troisième partie, nous proposons un nouvel élément fini de poutre mixte (à 6 ddl par nœud) en petits déplacements avec prise en compte de la non-linéarité matérielle de la poutre ainsi que du contact entre l'acier et le béton. Une stratégie efficace de type nœud mobile (Flying Node) est proposée pour déterminer l'étendue de la surface de contact au sein d'un élément fini et d'adapter le maillage de l'élément poutre/poteau. Pour la résolution du problème de contact, la technique du Lagrangien Augmenté a été retenue. On montre que dans certaines situations, le soulèvement modifie la redistribution des efforts. / The goal of this thesis is to develop computational tools for the nonlinear analysis of steel and composite steel-concrete structures under cyclic loading taking into account the actual behaviour of joint, material and geometry non-linearities and contact conditions at the steel-to-concrete interface. In particular, our efforts focuses on typical bolted end-plate connection between steel or composite beam and steel column. The objective is to develop a new «joint finite element" able to reproduce accurately the cyclic behavior of the beam-to-column connection. Next this model is combined with a non-linear steel/composite beam element considering slip and possible uplift at the interface. The thesis consists of three major parts. The first part deals with the behavior of a steel beam-to-column bolted end-plate connection under arbitrarily cyclic loading. The proposed model is based on an improved component method that closely follows the deformation of each component taking into account non-linearities induced by possible gap between the column flange and the end-plate. This model has been developed for a single row connection. In the case of multiple row bolted connection group effects may develop. Possible group effect between two bolt-rows has been implemented considering the model proposed by Cerfontaine based on the definition of the multi-surface yield criterion and the associated flow rule that govern deformation of equivalent springs. Only the case of perfect plasticity is considered. It is shown that the influence of the group effect is not negligible on the nonlinear response of the joint. In the second part, we have developed a flexible co-rotational two-noded beam with generalized elasto-plastic hinges at the beam ends. It is assumed that plastic deformations concentrate at these hinges. These hinges have the ability to elongate/shorten along the beam axis and to rotate. A family of asymmetric and convex yield surfaces of super-elliptic shape is considered for the plastic behavior of the hinges. By varying the roundness factor, an infinite nun1ber of yield surface are obtained. It is shown that the nonlinear response of bolted connections subjected to both bending and tension are conveniently modeled with such a yield surface. It was observed that cyclic loading produces pinching effect, cyclic softening and ductile behavior. Advantages and limitations of the approach are discussed. Finally, the third part is dedicated to the problem of contact at the interface of steel-concrete composite beams. A "new" finite element for composite steelconcrete beam is proposed. The beam element has 6 degrees of freedom per node. The concrete beam is allowed to separate from the steel beam. An efficient contact algorithm is proposed. The Flying node concept is introduced and used to determine the extent of the contact area within a single element and modify the mesh of the beam structure. The contact problem is solve using the Augmented Lagrangian Method. The influence of contact on the loading capacity of the beam and its influence on some design variables are highlighted.

In the early 1860s three Swedes, Nils Wilhelm Mitander,Julius Ramsay and Gustaf Wittenström, were engaged by theBritish to build and run charcoal-based ironworks in India.These works, the Burwai Iron Works of the British Government inthe case of Mitander and the privately owned Kumaon Iron Worksin the case of Ramsay and Wittenström, were both to bebased on the most modern European technology. The projects werepioneering in Indian ironmaking. The ambitions were high andstakes big, but after only a few years the projects were closedand the Swedes returned home.Landscapes of Technology Transferpresents a detailedstudy of the Kumaon and Burwai Iron Works, from their firstconception to their final closure. The investigation isbasically empirical and a fundamental question is: Why were theworks never brought into full and continuous production? The ironworks projects should be considered as processes oftechnology transfer rather than fully fledged and completedtransfers. In spite of this lack of success, or maybe becauseof it, the history of the ironworks and the Swedes also forms afruitful case to put other questions of wide relevance. Itexposes workings and effects of colonialism and offers anexplanation of the late development of India's iron and steelindustry and analyses of the complex totality forming theprerequisites for a successful transfer of technology. The longtraditions of bloomery ironmaking in India and ismarginalisation is also discussed. Landscapes of Technology Transferis a comprehensiveempirical study. From a local and individual perspective ittraces lines of connection across boundaries of time andgeography. The historical landscapes of technology transfer aredescribed in their cultural, social, economic and politicaldimensions and the thesis underlines the importance of a closeacquaintance with local settings and conditions, where historyis manifested in a physical presence. The remains of theironworks and theirlocal landscapes in present-day India areused as a central source for writing their histories. There isalso a strong emphasis on the use of photographs and drawingsas sources. The outcome of the projects was the result of the interplaybetween the local and the global, between a diversity ofconcrete factors influencing the construction of the works andtheir running and their colonial character. The studyemphasises the importance of technological systems andnetworks, both on a micro and a macro level. On a local leveldemanding logistics, a sometimes adverse climate, theprocurement of charcoal and iron ore in sufficient quantitiesand the build up of knowledge of ironmaking posed serious butnot insurmountable difficulties. Most obstacles were overcomealready during the first few years of the 1860s, the period ofthe Swedes, but to put the works into full and continuousproduction would have needed perseverance and purposefulefforts to support and protect the iron production, at leastduring an initial period. In the end the position of India as acolonial dependency, subjected to the primacy of Britishinterests, set the limits of the projects. Key words:History of technology, industrial heritagestudies, industrial archaeology, technology transfer,diffusion, technological systems, landscapes of technology,iron and steel, charcoal iron, direct and indirect ironmaking,bloomeries, 19th century, industrial history,industrialisation, de-industrialisation, underdevelopment,colonialism, India, Sweden, Great Britain, global history,annales. / <p>Qc 20170119</p>

The research was focused on the three major structural elements of a typical cold-formed steel building - shear wall, floor joist, and column. Part 1 of the thesis explored wider options in the steel sheet sheathing for shear walls. An experimental research was conducted on 0.030 in and 0.033 in. (2:1 and 4:1 aspect ratios) and 0.027 in. (2:1 aspect ratio) steel sheet shear walls and the results provided nominal shear strengths for the American Iron and Steel Institute Lateral Design Standard. Part 2 of this thesis optimized the web hole profile for a new generation C-joist, and the web crippling strength was analyzed by finite element analysis. The results indicated an average 43% increase of web crippling strength for the new C-joist compared to the normal C-joist without web hole. To improve the structural efficiency of a cold-formed steel column, a new generation sigma (NGS) shaped column section was developed in Part 3 of this thesis. The geometry of NGS was optimized by the elastic and inelastic analysis using finite strip and finite element analysis. The results showed an average increment in axial compression strength for a single NGS section over a C-section was 117% for a 2 ft. long section and 135% for an 8 ft. long section; and for a double NGS section over a C-section was 75% for a 2 ft. long section and 103% for an 8 ft. long section.

Made available in DSpace on 2017-06-01T17:57:30Z (GMT). No. of bitstreams: 1 dissertacao_adelmo_siqueira.pdf: 4077806 bytes, checksum: ca805c61a0f188f3cccb3e4d045ee770 (MD5) Previous issue date: 2010-12-01 / One can estimate that there are approximately six thousand four storey residential box-type buildings in Recife Metropolitan Region which presents structures in risk situation. Among those buildings, twelve collapsed spontaneously, thirteen were demolished and in many others it was observed serious pathologies that demanded restrictions to their occupation. This work presents a methodology to deal with this problem, contemplating technical aspect as well as risks issues. One expects to eliminate the stigma of these buildings and to contribute to give dignity and security back to their inhabitants through a work that must be done based on technical and scientific concepts accepted worldwide in structural engineering. The solution to the problem consists of a proposal to create a steel structure to be installed in such building that, in case of collapse of their support walls, should carry all loads that act on them. This solution was modeled and designed using a software called Metálica 3D, showing results that assure security to all load cases that usually act in this type of structure. One expects that the proposed solution can generate significant social impact, due to the occurrence of several accidents with this type of buildings constructed with non structural bricks carrying loads beyond its own weight / Estima-se que existam cerca de seis mil edifícios tipo caixão na região metropolitana do Recife que apresentam estrutura em situação de risco. Cerca de doze edifícios colapsaram espontaneamente, treze foram demolidos e dezenas de outros foram constatadas manifestações patológicas graves, motivando suas interdições. Este trabalho apresenta uma metodologia para o enfrentamento do problema, contemplando não apenas os aspectos técnicos, mas questões referentes aos riscos. Com isso se espera eliminar o estigma dessas edificações e resgatar a dignidade e segurança dos moradores dos prédios, através de um trabalho que tenham como base conceitos técnicos e científicos consagrados na Engenharia. A solução para o problema trata-se de uma proposta de criação de uma estrutura metálica a ser implantada nos prédios construídos em alvenaria resistente, em casos de falência das alvenarias que originalmente serviram de suporte para cargas que atuam na referida obra. Esta estrutura foi modelada e dimensionada pelo programa computacional Metálica 3D, apresentando resultados que responderam com total segurança todas as ações de carregamento que atuam nesse tipo de edificação para a modelagem adotada. Espera-se que a solução aqui proposta tenha um impacto social bastante significativo, dado a ocorrência de diversos acidentes com edifícios desta natureza, construídos em alvenaria resistente com a utilização de tijolos de vedação, vulgarmente conhecidos como prédios caixão

To provide a basis for the development of interaction curves for tubular beam-columns of annular cross section, a general purpose beam-column computer program is developed, and used to determine ultimate load capacities. The paper presents the analytical model and the computer method. The analytical results are compared with published test data as well as experimental data obtained as part of this project.

Founded in 1928, Iscor was intended to make South Africa self sufficient in the provision of steel while providing employment for poor whites. Economic considerations prevailed when Iscor began replacing expensive white labour with cheaper black labour. From 1934 to 1948 black labour was employed to curtail costs. While being replaced by black labour, white employees' salaries and fringe benefits remained better than those of their black colleagues. Affordable houses were provided for white employees while blacks were housed in overcrowded compounds. No medical or pension benefits were made available to black employees or their families, while white employees enjoyed both. White employees were provided with what were arguabley the finest sports facilities in the country while black facilities were neglected. With the National Party victory in 1948 more emphasis was placed on the employment of Afrikaans speaking white South Africans at the expense of blacks and English speaking whites. / History / M.A. (History)

Founded in 1928, Iscor was intended to make South Africa self sufficient in the provision of steel while providing employment for poor whites. Economic considerations prevailed when Iscor began replacing expensive white labour with cheaper black labour. From 1934 to 1948 black labour was employed to curtail costs. While being replaced by black labour, white employees' salaries and fringe benefits remained better than those of their black colleagues. Affordable houses were provided for white employees while blacks were housed in overcrowded compounds. No medical or pension benefits were made available to black employees or their families, while white employees enjoyed both. White employees were provided with what were arguabley the finest sports facilities in the country while black facilities were neglected. With the National Party victory in 1948 more emphasis was placed on the employment of Afrikaans speaking white South Africans at the expense of blacks and English speaking whites. / History / M.A. (History)