Percorrer por autor "Torres, Leonardo"
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- Accuracy of 2D numerical models towards the prediction of the fire resistance on LSF partition wallsPublication . Piloto, P.A.G.; Gomes, Stephan; Torres, Leonardo; Couto, Carlos; Real, Paulo VilaLightweight steel framing (LSF) walls are commonly used in modern buildings due to their high strength-to -weight ratio and readiness for installation. However, empty cavities within these walls can pose a fire risk if not properly addressed. In order to ensure the fire resistance and performance of LSF walls with empty cavities, various modelling techniques can be employed. Two-dimensional thermal models can also be used to simulate the behaviour of LSF walls with empty cavities in a fire scenario. These models can predict the spread of heat through the empty cavity, allowing designers to identify potential fire hazards and make adjustments to the design to mitigate those risks.Three different computational solution methods were used to compare the fire performance of LSF walls with void cavities. Solution method 1 considers the air-structure interaction in the cavity region. Solution method 2 considers the existence of interface elements for the radiation heat transfer in the cavity region allowing the cavity temperature prediction. Solution method 3 considers the convection and radiation in the cavity region with a prescribed cavity temperature from experiments (hybrid). Solution methods 1 and 3 give a small root mean square error (RMSE), when compared with solution method 2. Solution method 3 gives a better approx-imation because can capture the main fire events during the fire, such as the cracks and fall off. Based on the parametric study, a new proposal is presented to predict the fire resistance by insulation, depending on the gypsum type and thickness.
- Accurate 3D numerical models for the fire performance on lsf partition walls under different fire scenariosPublication . Piloto, Paulo A.G.; Silva, Renata; Frizzera, Giovanna; Torres, Leonardo; Couto, Carlos; Vila Real, Paulo; Mesquita, Luís M.R.; Lopes, NunoThis study presents the development and validation of advanced 3D numerical models to analyse the fire performance of non-load-bearing Light Steel Frame (LSF) partition walls under different fire scenarios, specifically the standard ISO 834 and HYDROCARBON fire. Medium-scale experimental fire resistance tests from prior research were used for validation, focusing on LSF walls with and without cavity insulation (external composite insulation). Three computational solution methods were compared and used to predict the fire behaviour of LSF walls with a void cavity. The finite element method was employed for transient thermal analysis with temperature-dependent material properties, including adaptations to simulate material degradation such as gypsum board cracking and rock wool melting under HYDROCARBON fire conditions. Hydrocarbon fires reduced fire resistance by an average of 57% compared to ISO 834 fires for cavity-insulated walls, whereas external insulation configurations showed less reduction.
- Avaliação do comportamento ao fogo de paredes exteriores em light steel framingPublication . Torres, Leonardo; Couto, Carlos; Vila Real, Paulo; Piloto, Paulo A.G.Este estudo avaliou o comportamento ao fogo de paredes em Light Steel Framing (LSF) através de quatro ensaios experimentais de pequena escala, sujeitos à curva de incêndio padrão ISO 834 pelo lado interior (revestido com gesso) e exterior (revestido com ISOLPRO). Como esperado, verificaram-se diferenças significativas no isolamento térmico (I) e no aquecimento dos perfis metálicos. As simulações numéricas por elementos finitos confirmaram a tendência observada experimentalmente, sobretudo no cenário de fogo pelo lado interior. Os ensaios demonstram-se essenciais para a calibração de modelos e para o desenvolvimento de soluções construtivas mais seguras.
- Fire performance of non-loadbearing light steel frame external walls: numerical simulationPublication . Torres, Leonardo; Couto, Carlos; Vila Real, Paulo; Piloto, Paulo A.G.This work investigates the fire behaviour of external walls, presenting a numerical study of six different typologies usually found in LSF practice with two fire scenarios affecting the inner and outer sides of the walls. The conclusions show that the temperature evolution is slower for outer side fires but, in these cases, the critical temperature of 350 °C is reached earlier in the steel profiles. Finally, this work shows that more studies are necessary to describe the fire resistance of external walls, in particular, when these elements have a loadbearing requirement.
- Modelling techniques for the fire performance of empty cavities in LSF wallsPublication . Piloto, Paulo A.G.; Gomes, Stephan; Torres, Leonardo; Couto, Carlos; Vila Real, PauloThree different solution models were used to compare the fire performance of LSF walls with void cavities. The first solution method considers the air-structure interaction in the cavity region. The second solution method considers the existence of interface elements for the radiation heat transfer in the cavity region allowing the bulk temperature prediction. The third solution method considers the convection and radiation in the cavity region with a prescribed bulk temperature from experiments (hybrid). Solution methods 1 and 3 give a smaller root mean square error (RMSE), when compared with solution method 2. Solution method 3 gives a better approximation because can capture the main fire events during fire testing, such as the cracks and fall off.
- Numerical study of the fire behaviour of external walls in light steel framingPublication . Torres, Leonardo; Couto, Carlos; Vila Real, Paulo M.M.; Piloto, P.A.G.This study focuses on the fire behaviour of external walls in Light Steel Frame (LSF) structures. Previous investigations have primarily addressed the fire behaviour of internal wall configurations, however, the increasing number of fires affecting external walls shows that their behaviour must also be understood. Therefore, this work investigates the fire behaviour of these elements, presenting a numerical study of six different typologies usually found in LSF practice by analysing the temperature evolution across the wall and in the steel profiles. The results show that the temperature evolution is slower when the fire is impacting the outer side of the wall but, in these cases, the recommended critical temperature of 350 ◦C is reached earlier in the steel profiles. Finally, this work shows that more studies are necessary to describe the fire resistance of external walls, in particular when these elements have a loadbearing function.