Coupled CFD–FEM analysis of steel column thermal behavior during vehicle fires in parking structures

Purpose This study is to investigate the thermal behavior of steel columns exposed to different localized vehicle fire scenarios in parking structures. Design/methodology/approach A computational fluid dynamics (CFD) simulation of vehicle fires was conducted using Fire Dynamics Simulator (FDS), followed by thermal analysis of the steel columns using ABAQUS. A one-way coupling approach was employed, where the adiabatic surface temperature (AST) output from FDS was applied as a boundary condition in the thermal model of ABAQUS. The fire simulation and transient thermal analysis coupling method were validated by comparing the predicted steel column temperatures with results from previous experimental studies, demonstrating strong consistency. Findings To assess the thermal response of steel columns, three key parameters were considered: different floor heights (2.5 m, 3.0 m and 4.0 m), various fire scenarios and different numbers of burning vehicles. The results indicate that flame impingement resulting from differences in storey height primarily influences the temperature at the upper portions of the columns. However, this does not lead to substantial increases in the overall temperature of the steel columns. Furthermore, simulation results show that even when a single vehicle fire propagates to ignite two adjacent vehicles, the maximum temperature of the steel columns remains relatively low. Originality/value This numerical study first presents an investigation into the thermal behavior of steel columns subjected to various vehicle fire scenarios, with particular emphasis on fire impingement effects across different storey heights.