Analyses of the effects of cooling and fire spread on steel-framed buildings

An existing computer model capable of predicting the response of three-dimensional semi-rigid steel framed buildings, including continuous floor systems, at elevated temperatures has been extended to include the possibility of extensive strain reversal within the material constitutive relationship. This allows the behaviour in cooling and the effect o f fire spread on steel-framed buildings to be investigated. A number of examples are presented to give an indication of the likely effects of cooling behaviour within the analysis. An initial study has also been made into the structural effects of fire spread from a single ignition point into adjacent bays of a two-dimensional steel building frame. It is shown that some of the distortions caused by the fire are increased by progressive fire spread, as compared with simultaneous burning across the same range of compartments.