Experimental tests and numerical simulation of the fire effect on non-load-bearing double-stud light steel framing walls

• Autor(a) principal: Alves, Matheus Henrique
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10198/23523
• topic: Double-stud light-steel framing walls; LSF walls, partition walls; fire resistance; thermal insulation; numerical analysis; simplified design method.; LSF walls; Partition walls fire resistance; Thermal insulation; Numerical analysis; Simplified design method; Engenharia da Construção

Partition double-stud light steel framing walls provide an enhanced insulation performance when exposed to fire conditions. However, the behaviour of different configurations of such assemblies at high temperatures is still not well understood. In this sense, this study aimed to assess the fire resistance in terms of insulation requirements of double-stud light steel framing walls clad with one or two Type F gypsum plasterboards on both sides and with or without ceramic fibre cavity insulation. A series of experimental tests were conducted by subjecting small-scale specimens to ISO 834 standard fire curve and the numerical validation of each numerical model was performed using the Finite Element Method with a hybrid approach. Also, a simplified approach was proposed based on the improved design model available in the literature. The results obtained in the experimental tests revealed that a wider cavity slows the heat transfer through the wall’s cross-section, delaying the temperature rise on the unexposed gypsum plasterboard. The use of ceramic fibre cavity insulation increases substantially the fire resistance of the wall, although the heating rate of the steel studs on the exposed side is faster if compared to the specimens without cavity insulation. Moreover, concerning the specimens with the cavity partially filled with ceramic fibre, if the insulation blanket is placed towards the exposed side, enhanced fire resistance is achieved. A hybrid approach was used to carry out the numerical analysis to determine the thermal response of each model throughout fire exposure using ANSYS® Multiphysics. It was verified that using different experimental curves to represent the temperature evolution inside the cavities or insulation blankets was essential to attain improved numerical results. Also, the concept of an air thermal layer located at specific regions of the wall models led to better and more consistent results. Moreover, the modified improved design method showed consistent results when compared with the experimental values. Overall, the predicted insulation fire resistance of the model specimens agreed well with the experimental data and useful information was provided to support further numerical and experimental studies.