Advanced Analysis for Performance-based Design of Steel Structures Exposed to Fires

Abstract

This paper presents an advanced plastic hinge analysis method that can be used to assess the performance of steel structures exposed to fire. The main feature of the analysis is to use as few elements as possible to model each structural member and to obtain a realistic representation of the global nonlinear effects of the structure. Natural fires are simulated using the proposed multizone and radiation models. The transient heat transfer is computed using a finite element method. Bounding surface theory is employed to allow for gradual plastification of steel cross sections. Performance-based assessments are carried out on a multistory car park structure and an arched frame exposed to localized car combustion. The effects of beam span, fire source location, and fire spread on the structural behaviors are investigated.