Navegando por Assunto "Reliability"

Agora exibindo 1 - 2 de 2

Acesso aberto (Open Access)
Confiabilidade aplicada à análise da estabilidade de taludes: um estudo de caso de uma encosta fluvial no norte amazônico
(Universidade Federal do Pará, 2021-04-02) NASCIMENTO, Rafael Silva do; TEIXEIRA, Marcelo Rassy; http://lattes.cnpq.br/8912916360456192
Among the geotechnical structures, the river slopes stand out for the uncertainties in their properties. In addition, the use of coupled reliability methods in the analysis of slopes has grown, in contrast to deterministic methods that do not consider uncertainties. In this context, the present work presents the study of the reliability of a fluvial slope in the Amazon region that suffered a rupture. For this, three reliability methodologies were used (Monte Carlo, FOSM and PEM), using the limit equilibrium method and finite elements. The properties of the hillside soft clays were treated as random variables and the reliability indicators for each methodology were obtained. In addition, sensitivity analyzes of these parameters were carried out. The results of the slice models were compared to the numerical results. Finally, it was concluded that the uncertainties in the properties of soft soils were not sufficient to cause the rupture of the slope, therefore, another factor(s) must have triggered the rupture.
Acesso aberto (Open Access)
Modelagem da disponibilidade de uma unidade geradora da UHE-Tucuruí
(Universidade Federal do Pará, 2013-07-04) MOREIRA, Pedro Igor Carvalho; NEVES, Renato Martins das; http://lattes.cnpq.br/6538317425557058
Since 2004, the regulatory rules in the Brazilian Electricity Sector has changed. The agents who act in this market have experienced a rise in new business disputes, showing an increase in competitiveness. The availability of physical assets and maintenance costs are presented as key points of these agents competitiveness. This work aims to present a methodology of Availability Analysis of Repairable Systems during the design or operational phases, covering the measurement of maintenance costs versus the acquisition costs to an expected performance level. The suggested methodology takes the System Block Diagram and exports to the Successful Tree Analysis format, composed by logic gates "AND" and "OR" where each represents a subsystem in the main system. The analyst may re-evaluate the system's topology, adding or removing redundancies in order to adjust the performance to the requirements of availability, acquisition and maintenance costs. As results of this work were identified gaps in the standards rules which defines how to control the assets performance, was established a systematic integration of modeling techniques for reliability and availability, performance indicators of Scheduled Maintenance were incorporated, different scenarios were modeled for an Oil Circulation System and was applied to an entire Hydraulic Generating Unit by modeling the critical components in the main systems.