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 subsumes conventional nonlinear analysis in that it can be applied to the two cases of fire and explosion loading in isolation and, more significantly, within the same analysis. The resulting integrated approach can therefore be used to study the behaviour of steel members and frames subject to scenarios of explosion loading followed by fire, effectively enabling the influence of explosion on the fire resistance to be evaluated. The paper describes the component beam-column formulations and discusses their incorporation within an adaptive analysis framework, which is largely responsible for the considerable efficiency of the proposed method. Details of the required elasto-plastic material models are finally presented, including the adopted models 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 accuracy and efficiency of the proposed method, and which investigate the influence of explosion on the fire resistance of steel members and frames.