11 resultados para deterministic safety analysis


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertação para obtenção do Grau de Mestre em Engenharia e Gestão Industrial

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Assessing the safety of existing timber structures is of paramount importance for taking reliable decisions on repair actions and their extent. The results obtained through semi-probabilistic methods are unrealistic, as the partial safety factors present in codes are calibrated considering the uncertainty present in new structures. In order to overcome these limitations, and also to include the effects of decay in the safety analysis, probabilistic methods, based on Monte-Carlo simulation are applied here to assess the safety of existing timber structures. In particular, the impact of decay on structural safety is analyzed and discussed, using a simple structural model, similar to that used for current semi-probabilistic analysis.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

In developed countries, civil infrastructures are one of the most significant investments of governments, corporations, and individuals. Among these, transportation infrastructures, including highways, bridges, airports, and ports, are of huge importance, both economical and social. Most developed countries have built a fairly complete network of highways to fit their needs. As a result, the required investment in building new highways has diminished during the last decade, and should be further reduced in the following years. On the other hand, significant structural deteriorations have been detected in transportation networks, and a huge investment is necessary to keep these infrastructures safe and serviceable. Due to the significant importance of bridges in the serviceability of highway networks, maintenance of these structures plays a major role. In this paper, recent progress in probabilistic maintenance and optimization strategies for deteriorating civil infrastructures with emphasis on bridges is summarized. A novel model including interaction between structural safety analysis,through the safety index, and visual inspections and non destructive tests, through the condition index, is presented. Single objective optimization techniques leading to maintenance strategies associated with minimum expected cumulative cost and acceptable levels of condition and safety are presented. Furthermore, multi-objective optimization is used to simultaneously consider several performance indicators such as safety, condition, and cumulative cost. Realistic examples of the application of some of these techniques and strategies are also presented.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Dissertação para obtenção do Grau de Mestre em Engenharia e Gestão Industrial

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Dissertação para obtenção do Grau de Mestre em Engenharia e Gestão Industrial

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Dissertação para obtenção do Grau de Mestre em Segurança e Higiene do Trabalho

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Esta dissertação teve como objetivo a realização de uma análise e avaliação de riscos, no setor da construção, durante a execução da obra de construção civil Casa para todos BV3 em Boa Vista, Cabo Verde, bem como deixar à empresa de acolhimento, CFS construções S.A., um plano de ação de melhorias para implementação em obras futuras. Fez-se um acompanhamento no local de trabalho com observação direta durante quatro meses, para identificar os riscos a que se encontram expostos os trabalhadores desta obra. Utilizou-se o método Job Safety Analysis, que abrangeu as diferentes atividades envolvidas na obra de construção civil estudada o que permitiu definir cada atividade e dividir as mesmas em tarefas para uma análise e avaliação mais profunda/detalhada. Foram encontradas oito atividades principais. As tarefas identificadas como mais problemáticas foram os trabalhos com ferramentas de mão e a manipulação de objetos. De entre os riscos mais elevados, destaca-se o «constrangimento fisico», o qual geralmente dá origem a lesões no sistema músculo-esquelético. Sugeriram-se várias recomendações de melhoria com prioridade para o risco mencionado.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Biotecnologia

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Corrosion of reinforcement bars in concrete structures is the most significant deterioration mechanism in these structures. Corrosion is extremely difficult to predict and, consequently, can be regarded as an unpredictable event. Following this, robustness assessment methods can be employed to define the susceptibility of a structure to corrosion. In this work, robustness is measured in terms of the remaining safety of a deteriorated structure. The proposed methodology is illustrated by means of a reinforced concrete (RC) slab subjected to dead and live loads. The performance of the corroded slab is evaluated using non-linear analysis. The reliability index is adopted to assess the safety of the deteriorated structure. To compute the reliability index a strategy combining the First Order Reliability Method (FORM) and the Response Surface Method (RSM) is used.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Ship tracking systems allow Maritime Organizations that are concerned with the Safety at Sea to obtain information on the current location and route of merchant vessels. Thanks to Space technology in recent years the geographical coverage of the ship tracking platforms has increased significantly, from radar based near-shore traffic monitoring towards a worldwide picture of the maritime traffic situation. The long-range tracking systems currently in operations allow the storage of ship position data over many years: a valuable source of knowledge about the shipping routes between different ocean regions. The outcome of this Master project is a software prototype for the estimation of the most operated shipping route between any two geographical locations. The analysis is based on the historical ship positions acquired with long-range tracking systems. The proposed approach makes use of a Genetic Algorithm applied on a training set of relevant ship positions extracted from the long-term storage tracking database of the European Maritime Safety Agency (EMSA). The analysis of some representative shipping routes is presented and the quality of the results and their operational applications are assessed by a Maritime Safety expert.