Browsing by Author "Couto, David"
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- Comportamento ao fogo de lajes celulares de pavimento ou cobertura em madeira com perfurações circularesPublication . Couto, David; Piloto, P.A.G.; Fonseca, E.M.M.As boas características mecânicas, térmicas e acústicas que a madeira proporciona numa estrutura está a levar a um aumento da sua utilização, sendo este um material ideal para utilizar em pavimentos e coberturas. Como a madeira é um material combustível, é importante prever o seu comportamento em situação de incêndio, pois a madeira nessas condições, carboniza diminuindo a secção de material intacto e consequentemente, a sua resistência estrutural. Neste estudo apresentam-se dois modelos de laje celular com perfurações circulares semelhantes. As lajes são construídas em madeira abeto que serão utilizadas em dois ensaios experimentais. Os ensaios baseiam-se em colocar as lajes expostas a uma situação de incêndio normalizado para determinação do perfil de temperaturas e da velocidade de carbonização em função da perfuração associada a cada uma das lajes. Apresenta-se também um modelo numérico em regime transiente não linear térmico com as mesmas características da laje em madeira utilizada validado experimentalmente.
- Fire resistance of cellular wooden slabs with rectangular and circular perforationsPublication . Couto, David; Fonseca, E.M.M.; Piloto, P.A.G.; Meireles, J.M.; Barreira, Luísa; Ferreira, DéboraThis work presents a numerical approach in arder to predict the behaviour and the perfonnance of typical cellular wooden slabs with rectangular and circular perforations when submitted to fire conditions. For this purpose a 3D numerical model was validated with different experimental tests at real scale obtained in laboratory m four cellular wooden slabs. This study was conducted in accordance with European standard EN 1365-2 and using a fire resistance íümace which complies the requirements ofEN 1363-1. The thermal perfomiance of the slab and the charring rate of the exposed siiïface will be compared for each type of perforations.
- Fire resistance of cellular wooden slabs with rectangular and circular perforationsPublication . Couto, David; Fonseca, E.M.M.; Piloto, P.A.G.; Meireles, J.M.; Barreira, Luísa; Ferreira, DéboraThis work presents a numerical and experimental approach in order to predict the thermal behaviour and the performance of typical cellular wooden slabs with rectangular and circular perforations when submitted to fire conditions. For this purpose a 3D numerical model was validated with different experimental tests at real scale obtained in laboratory in four cellular wooden slabs. This study was conducted in accordance with European standard (EN 1365-2, 1999) and using a fire resistance furnace which complies the requirements of European standard (EN 1363-1, 1999). The numerical temperatures show good agreement with experimental results. The numerical model can easily be adjusted for other constructive solutions, to facilitate fire safety tests, in buildings with wooden slabs used in floors or in ceilings applications.
- Fire safety in perforated wooden slab, a numerical approachPublication . Fonseca, E.M.M.; Couto, David; Piloto, P.A.G.The main goal of this work is to present a numerical model to assess the fire safety of wooden slabs with rectangular perforations at the ceiling. These typical constructions have good sound absorption, heat insulation and relevant architectonic characteristics. They are used in many civil applications: concert and conference halls, classrooms, nurseries, airports, hotels, shopping, universities, and many other public buildings. These panels are normally installed at lower level in building constructions due essential an easy maintenance. Depending of the installation requirement, the perforated wooden slabs could have an insulation material inside the cavities. In this work the proposed numerical model could be used for different design constructive solutions. For guarantee the fire rating in a typical used perforated wooden slab, a transient thermal analysis with nonlinear material behaviour will be solved using ANSYS program. This study allows verifying the evolution of the temperature and the char-layer throughout a wooden slab with different rectangular perforations and considering the insulation effect inside the cavities. The developed numerical model allows future studies and simultaneously characterizes the effect of rectangular perforations in wooden slabs to minimize the fire risk. The numerical model can easily be adjusted for other constructive solutions, to facilitate fire safety validation, in buildings with several wooden slabs assemblies used in floors or in ceilings applications.
- Fire safety in wooden slabs: the size effect on perforated cellsPublication . Fonseca, E.M.M.; Couto, David; Piloto, P.A.G.; Meireles, J.M.O principal objetivo deste trabalho é apresentar um modelo numérico e experimental para avaliar a segurança ao fogo de lajes de madeira celulares com perfurações retangulares e circulares. O espaço aberto das perfurações é determinante na evolução da temperatura.
- Perforated cellular wooden slabs under fire: Numerical and experimental approachesPublication . Couto, David; Fonseca, E.M.M.; Piloto, P.A.G.; Meireles, J.M.; Barreira, Luísa; Ferreira, DéboraThis work presents a numerical and experimental approach in order to predict the fire resistance of perforated cellular wooden slabs. The wooden slabs are lightweight, easy installation, excellent architectural, thermal and acoustic characteristics. However, its high vulnerability to fire, requires their behaviour assessed accurately. Wood material produces a surrounding char layer in depth, when exposed to fire resulting in a reduced residual section. For this purpose, different cellular wooden slabs, with the bottom surface perforated, including different small and large rectangles and circles, were tested and submitted to fire exposure. The experimental study was conducted in laboratory in accordance with European standard (EN1365-2, 2012), using a fire resistance furnace which complies the requirements of European standard (EN1363-1, 2012). Also a three-dimensional thermal and transient numerical model, using a finite element program Ansys®, was validated with experimental tests at real scale. The numerical and experimental results show good agreement. The numerical model can easily be adjusted for other constructive solutions, in order to facilitate fire safety tests, in buildings with wooden slabs used in floors or in ceilings applications.