Fire Resistance and Structural Behavior of Light Steel Frame (LSF) Walls Under Fire Conditions

Resumo

This study investigates the behavior of structural walls in Light Steel Frame (LSF) under fire conditions, focusing on determining the critical temperature. The research involves a comparison between full-scale experimental test results and three-dimensional numerical simulations, aiming to validate the computational model. Three specimens were tested: a 3×1 m specimen to assess load-bearing capacity at ambient temperature, and two 3×3 m specimens subjected to different loading levels (84% and 27%). The numerical model was developed in four stages: (i) linear analysis to determine instability modes and critical loads; (ii) GMNIA analysis to estimate load-bearing capacity at ambient temperature; (iii) transient thermal analysis to obtain the temperature history; and (iv) thermomechanical analysis to evaluate the structural response under constant load and high temperatures. The numerical results were compared to the experimental data using the root mean square error (RMSE), showing good correlation when RMSE lt; 100 °C. The results demonstrate the reliability of the numerical model in predicting the thermo-structural performance of LSF walls, highlighting its potential as a viable alternative to complex and costly experimental tests. Additionally, a methodology is proposed to verify the similarity between computational models and physical tests, contributing to advancements in the analysis of LSF elements under fire conditions.