THERMAL ANALYSIS OF REINFORCED CONCRETE BEAMS SUBJECTED TO LOCALIZED FIRE USING CFD-FEM MODELS

Abstract

The versatility and high load capacity of reinforced concrete are the main reasons for its massive use in various infrastructures such as buildings, bridges, among others. Outside of normal operating loads, these structures can be subjected to accidental loads such as those generated by localized fires. Current regulations offer some options for analyzing this type of phenomena. Models based on Computational Fluid Dynamics (CFD) are the most suitable; However, given its complexity, its use is not widespread, opting for simplified methodologies. This work shows a methodology that couples CFD models for fire simulation and thermal models in Finite Elements (EF), to obtain the temperature field of a reinforced concrete beam subjected to a localized fire scenario. The analysis was carried out with a sequentially coupled unidirectional model in which, after extracting the heat transfer coefficients and adiabatic surface temperatures from the CFD model, these values are included (after manipulation using a FORTRAN program) in the EF model, to obtain the temperature fields. With the results obtained, it is concluded that the use of this methodology allows the temperatures in the beam to be adequately estimated for the case considered, making it possible to use them in a subsequent thermo-mechanical analysis.