PERFORMANCE BASED ANALYSIS OF COLD-FORMED STEEL COLUMNS UNDER FIRE CONDITIONS WITH RESTRAINED THERMAL ELONGATION

Resumo

In the present paper a performance based approach is developed for assessing the fire resistance of single
and built-up cold formed steel (CFS) columns at elevated temperature restrained to thermal elongation subjected
to axial compressive loading using finite element models and the Reliability Based Design (RBD). In the first
studies Monte Carlo simulation was selected and the analyzed variables were the material’s mechanical properties,
Young’s module (E) and yield stress (fy), and the level of stiffness of the surrounding structure (K). According
to the results from the preliminary studies the use of high computational resources would be a limitation. As an
alternative to work around this problem the Latin Hypercube Sample (LHS) method was chose. In the sequence
of this work the results obtained from the performance based approach was compared to that obtained using the
simplify method proposed by the ABNT NBR 14323:2013 to determine the axial compression resistance force of
CFS columns in fire situation. Finally, was evaluate among other aspects the probability of failure associated with
each method.