Using adiabatic surface temperature for thermal calculation of steel members exposed to localized fires

This paper provides a new way to calculate the temperature of steel components in localized fires. A newly developed concept named adiabatic surface temperature (AST) on fire-structural interface research has been used in the calculation to represent the fire exposed boundary conditions. Based on AST, a simple heat transfer model with the capability of considering heat conduction among different parts of the steel sections has been proposed. The popular CFD code FDS (version 5.3.0), which can output ASTs, has been adopted to simulate the heating of a steel beam and a steel column in a localized fire. Steel temperatures calculated by the proposed model agree very well with the results from CFD simulation. Studies also obviously show that using the surrounding gas temperatures for thermal calculation of steel members exposed to fire might yield unreasonable and unsafe results.