Simulation Methodology for Coupled Fire-Structure Analysis: Modeling Localized Fire Tests on a Steel Column

Advanced simulation methods are needed to predict the complex behavior of structures exposed to realistic fires. Fire dynamics simulator (FDS) is a computational fluid dynamics code, developed by NIST for fire related simulations. In recent years, there has been an increase in use of FDS for performance-based analysis in the area of structural fire research. This paper discusses the FDS–finite element method (FEM) simulation methodology for structural fire analysis. The general methodology is described and a validation study is presented. A data element used to transfer data from FDS to FEM codes, the adiabatic surface temperature, is discussed. A tool named fire-thermomechanical interface is applied to transfer data from FDS to ANSYS. A high temperature stress–strain model for structural steel developed by NIST is included in the FEM analysis. Compared to experimental results, the FDS–FEM method predicted both the thermal and structural responses of a steel column in a localized fire test. The column buckling time was predicted with a maximum error of 7.8%. Based on these results, this methodology has potential to be used in performance-based analysis.