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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Ice load prediction for design of ice-going ships for inland waterways

Zhang, Meng January 2019 (has links)
With increasing interest in utilizing the inland waterways (IWW) in European countries, the design of IWW vessels gains attention both from a transport efficiency and an emission control point of view. However, unlike in western and central European countries, in Nordic countries, e.g. Sweden, IWW ships must deal with ice on the fairway during every winter. Usually, IWW ships are designed without ice concerns and are structurally weaker compared to ships designed according to ice class notification from the classification societies. Developing such ships requires particular concerns since there is no strict requirements regarding ice class notifications for IWW ships. A primary challenge is to estimate both the global and local ice loads acting on the ship hull structure. To consolidate the design problems for IWW ice-going ships, Lake Mälaren is selected. Ice conditions, i.e. ice type and concentration, and ice data, e.g. ice thickness and ice flexural strength, are extracted and analysed for the ice load estimation. The ice mechanical properties have great influence on the ice load. Ice characteristics are studied based on empirical formulae and properties are calibrated by reference data. The deterministic approach is widely used to predict the ice loads. It is suitable when all variables, i.e. ship geometry and ice properties, are known and refers to rule-based design hereby. For first year light ice conditions in Lake Mälaren, the Finnish Swedish Ice Class Rule (FSICR) is widely used. The thesis uses guidelines from the Finnish Swedish Ice Class Rules as a reference and compare the results with other methods. The probabilistic approach, on contrary, is useful when certain variables are unknow, which are interpreted as random variables, for instance ice breaking pattern. Here the probabilistic method and ice-hull interaction mechanism are studied. The probabilistic method simplifies the ice pressure in relation to the contact area between the ice and the ship hull. It predicts maximum ice pressure acting on the ship hull based on field ice test data and ice exposure conditions. Such semi-empirical method can be used regardless of ship type and size. For this, a numerical model is introduced based on ice-hull collision mechanisms and the essential ice breaking characteristics. The physical mechanism is studied for idealizing ship-ice impact model. The idealization model includes the ice failure process, ice conditions and ship geometry. The ice failure is assumed to be initiated by crushing ice and followed by breaking due to bending failure. Ice properties are set as constant values without any variations. The stochasticity in interact process is represented by randomness in collision location and number of pieces of ice floe formed after breaking. An energy method is used to calculate the ice crushing force, indentation displacement and contact area. The ice bending scenario is simplified as an infinite plate resting on an elastic foundation under a concentrated load. Ice impact load and critical load can be obtained for global and local structural assessment respectively. The structural responses and structural strength of a representative panel at linear and nonlinear contexts are investigated as well. Ship structure is commonly designed with material yield strength as limit. However, the study shows a lighter structure can be achieved if plastic deformation is allowed without causing failure. Therefore, the design can be optimized with regards to ice loading capacity and weight control.
12

Metamorfose da várzea paulistana: energia, saneamento e urbanização / The metamorphosis of São Paulo´s floodplain: energy, sanitation and urbanization

Gabriel Rodrigues Grinspum 09 May 2014 (has links)
O complexo hidrelétrico da Serra de Cubatão foi considerado a grande obra de engenharia da primeira metade do século XX no Brasil. Este complexo polêmico foi possível graças à opção do poder público de legitimar o predomínio das forças produtivas e do capital na incorporação das planícies aluviais do rio Pinheiros à malha urbana da cidade, permitindo a execução de um projeto de infraestrutura que transformou o leito natural e sinuoso do rio Pinheiros em um canal de derivação das águas do rio Tietê, que passam pela bacia de São Paulo e são desviadas para a geração de energia, lançando esta água Serra do Mar abaixo. A sinergia obtida com as múltiplas funções incorporadas ao projeto da São Paulo Tramway, Light and Power Company acelerou o processo de construção da cidade sobre os novos terrenos metamorfoseados. Este ganho de tempo, proporcionado pelo capital internacional investido, contrapõe-se à ausência, no espaço urbano, de infraestruturas e equipamentos públicos essenciais para o equilíbrio socioambiental da metrópole paulistana. A dissertação aborda a transformação da natureza do lugar e a transformação das prioridades na infraestrutura urbana já instalada. Apresenta, em seu desenvolvimento, um diálogo entre o Projeto da Serra executado pela Companhia Light e o plano apresentado pelo Município de São Paulo, através da Comissão de Melhoramentos do Rio Tietê, para o combate às enchentes, diluição de efluentes e navegação no trecho do rio que fazia frente à cidade. Os dois projetos, delineados na década de 20, são partes distintas de uma mesma iniciativa da sociedade, que tinha como os principais propósitos o progresso, o avanço sobre as planícies aluviais paulistanas, a valorização da terra, o saneamento e a integração da metrópole. / The hydropower complex of Serra de Cubatão was considered the greatest engineering work of the first half of the 20th Century in Brazil. This controversial complex was made viable because the government has chosen to legitimize the predominance of the forces of production and capital in the incorporation of the floodplains of the Pinheiros River into the urban network of the city allowing the implementation of an infrastructure project that turned the river\'s natural and sinuous bed into a bypass channel of the waters from the Tietê River, which flow through the basin of São Paulo and are diverted for power generation , being discharged down the Serra do Mar. The synergy resulting from the multiple functions that were incorporated to the Project implemented by São Paulo Tramway, Light and Power Company accelerated the process of construction of the city on new metamorphosed land plots. This time saving initiative, which was enabled by the international capital invested, is opposed to the lack of essential public infrastructure and equipment in the urban space, which are essential for the socio-environmental balance of the metropolis of São Paulo. This dissertation addresses the transformation in the nature of the place and the changes in the priorities related to the infrastructure already installed. It introduces throughout its development a dialog between the Projeto da Serra performed by Companhia Light and the plan created by the City of São Paulo, through the Comissão de Melhoramentos do Rio Tietê (Comission for Improving the Tietê river), which established initiatives to fight floods, approached the dilution of effluents and navigation in the part of the river that stretched along the city. Both projects, outlined during the 20\'s, are different parts of the same initiative performed by society, whose main objectives were progress, the occupation of the floodplains of São Paulo, increasing land value, sanitation and the integration of the metropolis.
13

Metamorfose da várzea paulistana: energia, saneamento e urbanização / The metamorphosis of São Paulo´s floodplain: energy, sanitation and urbanization

Grinspum, Gabriel Rodrigues 09 May 2014 (has links)
O complexo hidrelétrico da Serra de Cubatão foi considerado a grande obra de engenharia da primeira metade do século XX no Brasil. Este complexo polêmico foi possível graças à opção do poder público de legitimar o predomínio das forças produtivas e do capital na incorporação das planícies aluviais do rio Pinheiros à malha urbana da cidade, permitindo a execução de um projeto de infraestrutura que transformou o leito natural e sinuoso do rio Pinheiros em um canal de derivação das águas do rio Tietê, que passam pela bacia de São Paulo e são desviadas para a geração de energia, lançando esta água Serra do Mar abaixo. A sinergia obtida com as múltiplas funções incorporadas ao projeto da São Paulo Tramway, Light and Power Company acelerou o processo de construção da cidade sobre os novos terrenos metamorfoseados. Este ganho de tempo, proporcionado pelo capital internacional investido, contrapõe-se à ausência, no espaço urbano, de infraestruturas e equipamentos públicos essenciais para o equilíbrio socioambiental da metrópole paulistana. A dissertação aborda a transformação da natureza do lugar e a transformação das prioridades na infraestrutura urbana já instalada. Apresenta, em seu desenvolvimento, um diálogo entre o Projeto da Serra executado pela Companhia Light e o plano apresentado pelo Município de São Paulo, através da Comissão de Melhoramentos do Rio Tietê, para o combate às enchentes, diluição de efluentes e navegação no trecho do rio que fazia frente à cidade. Os dois projetos, delineados na década de 20, são partes distintas de uma mesma iniciativa da sociedade, que tinha como os principais propósitos o progresso, o avanço sobre as planícies aluviais paulistanas, a valorização da terra, o saneamento e a integração da metrópole. / The hydropower complex of Serra de Cubatão was considered the greatest engineering work of the first half of the 20th Century in Brazil. This controversial complex was made viable because the government has chosen to legitimize the predominance of the forces of production and capital in the incorporation of the floodplains of the Pinheiros River into the urban network of the city allowing the implementation of an infrastructure project that turned the river\'s natural and sinuous bed into a bypass channel of the waters from the Tietê River, which flow through the basin of São Paulo and are diverted for power generation , being discharged down the Serra do Mar. The synergy resulting from the multiple functions that were incorporated to the Project implemented by São Paulo Tramway, Light and Power Company accelerated the process of construction of the city on new metamorphosed land plots. This time saving initiative, which was enabled by the international capital invested, is opposed to the lack of essential public infrastructure and equipment in the urban space, which are essential for the socio-environmental balance of the metropolis of São Paulo. This dissertation addresses the transformation in the nature of the place and the changes in the priorities related to the infrastructure already installed. It introduces throughout its development a dialog between the Projeto da Serra performed by Companhia Light and the plan created by the City of São Paulo, through the Comissão de Melhoramentos do Rio Tietê (Comission for Improving the Tietê river), which established initiatives to fight floods, approached the dilution of effluents and navigation in the part of the river that stretched along the city. Both projects, outlined during the 20\'s, are different parts of the same initiative performed by society, whose main objectives were progress, the occupation of the floodplains of São Paulo, increasing land value, sanitation and the integration of the metropolis.

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