Browsing by Author "Meda, Alberto"
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- Fire behaviour of non-load bearing double stud cold-formed steel frame wallsPublication . Alves, Matheus Henrique; Piloto, P.A.G.; Aiko Kimura, Erica F.; Constantini, Giada; Ianni, Alessandro; Meda, AlbertoThis work investigates the behaviour of Double stud Light Steel Frame (LSF) walls under ISO834 standard fire through a series of experimental tests. The walls were covered on both sides with one or two fire-resistant gypsum plasterboards (Type F), and the cavity of the steel frame was either empty, partially or fully insulated with ceramic fibre. The fire resistance of the assemblies is improved due to the existence of a wider cavity, the employment of additional gypsum plasterboard layers and the use of ceramic fibre cavity insulation. In partially insulated assemblies, significantly higher fire resistance is achieved when the ceramic fibre is placed towards the fire-exposed gypsum plasterboard. Moreover, the number of studs in contact with the unexposed gypsum plasterboard affects the fire resistance of the specimens. The experimental data acquired is useful to conduct further numerical analyses and experimental studies, as well as to understand the unique thermal behaviour of different configurations of double stud LSF walls at elevated temperatures.
- Fire performance of non‐load‐bearing double‐stud light steel frame walls: experimental tests, numerical simulation, and simplified methodPublication . Alves, Matheus Henrique; Constantini, Giada; Ianni, A.; Kimura, Érica Fernanda Aiko; Meda, Alberto; Piloto, P.A.G.Double-stud light steel frame (LSF) walls provide an enhanced insulation performance when exposed to fire conditions. However, the behavior of different configurations of such assemblies under fire is not well understood. Thus, this study aimed to assess the fire resistance of non-load-bearing double-stud LSF walls subjected to ISO834 standard fire. The walls were lined with one or two type F gypsum plasterboards on each side, using cavity uninsulated or insulated with ceramic fiber. The experimental tests revealed that a wider cavity slows the heat transfer through the cross-section, delaying the temperature rise on the unexposed surfaces. The use of ceramic fiber insulation substantially increases the fire resistance of the wall and when the cavity is partially filled with this material, if the blanket is placed towards the exposed side, enhanced insulation fire resistance is achieved. Based on the finite element method, a numerical validation was conducted using a special hybrid approach that used experimental temperature values inside the cavities or insulation blankets. This approximation was essential to improve the numerical results. Also, the employment of an air layer, located at specific regions of the models, helped to improve the numerical results, introducing an extra thermal resistance. A new simplified approach was proposed based on the improved design model available in the literature, and the results obtained are consistent with the experimental results. The predicted insulation fire resistance of the numerical and simplified methods agreed well with the experimental results and useful information is supplied to support further numerical and experimental studies.
- Inelastic behaviour of partially encased sections: numerical comparisonPublication . Piloto, P.A.G.; Ramos Gavilán, Ana Belén; Mesquita, L.M.R.; Meda, AlbertoPartially encased sections are made of composite steel and concrete casted between flanges. They present an attractive solution in comparison with bare steel or reinforced concrete counterparts. This paper intends to validate experimental results for bending and axial loading members at room temperature, (Elghazouli et al, 2008). The experiments were conducted at the Imperial College in London and aimed to provide essential data for validating future analytical and design studies. This numerical comparison is based on three dimensional finite element modelling, simulating bond contact and failure of concrete. The numerical results agree well with experimental results.