An integrated adaptive environment for fire and explosion analysis of steel frames - Part I: analytical models

This paper presents a new method for the nonlinear analysis of steel frames subject to fire and explosion loading conditions. The proposed method subs umes conventional nonlinear analysis in that it can be applied to the two c ases of fire and explosion loading in isolation and, more significantly, wi thin the same analysis. The resulting integrated approach can therefore be used to study the behaviour of steel members and frames subject to scenario s of explosion loading followed by fire, effectively enabling the influence of explosion on the fire resistance to be evaluated. The paper describes t he component beam-column formulations and discusses their incorporation wit hin an adaptive analysis framework, which is largely responsible for the co nsiderable efficiency of the proposed method. Details of the required elast o-plastic material models are finally presented, including the adopted mode ls for steel subject to elevated temperatures, creep and high strain-rates. The companion paper provides several verification and application examples , using the nonlinear analysis program ADAPTIC, which demonstrate the accur acy and efficiency of the proposed method, and which investigate the influe nce of explosion on the fire resistance of steel members and frames. (C) 20 00 Elsevier Science Ltd. All rights reserved.