Fire-thermomechanical interface model for performance-based analysis of structures exposed to fire

Abstract

This paper presents an interface model to perform a one-way coupling between a fire simulation (CFD model) and a structural analysis (FEM model) aimed at performance-based analysis of structures exposed to fire. The Fire-Thermomechanical Interface (FTMI) model is capable of processing the results from a fire simulation to properly account for the heat transfer by convection and radiation, between the fire and the exposed surfaces, based on Adiabatic Surface Temperature concept. The methodology is presented and verified against simple cases, and the improvements required to achieve complex geometries are introduced. An application is also presented evaluating the fire-thermomechanical behavior of an H-profile column under a localized fire. At the end of the analysis, it is possible to obtain the structural behavior under specific fire scenarios. An automated procedure is created to surpass the isolated member analysis, allowing the simulation of the behavior of global structures discretized with shell and/or solid elements under fire conditions. In these examples, both solid and shell elements are used to demonstrate that the procedure can be applied to evaluate the global behavior of structures. The results also suggest that the methodology can provide reliable performance-based analyses.