| Abstract: | This paper describes a study into the fire behaviour of open‐web steel trusses supporting concrete floor slabs, exposed to a range of realistic design fires. This study is intended to give some insight into the possible structural behaviour of the floor trusses in the World Trade Center (WTC) towers. The analysis was carried out using a non‐linear finite element program SAFIR. The trusses were analysed with and without protective insulation for several different fires, each with three types of connections; pinned at both ends, simply supported, and simply supported with an axial spring. This paper shows that the likely failure mode of the floor truss depends on the connection strength, and emphasizes the importance of ensuring that the insulation remains intact. Unlike the actual event in the WTC with multiple floors exposed to fire, this analysis only considers a single floor, hence the results from this analysis do not confirm the actual behaviour of the buildings while they collapsed. Copyright © 2004 John Wiley & Sons, Ltd. |
