Numerical assessment of castellated stainless steel columns under axial compression and high temperatures

Abstract

This study analyzes castellated stainless steel columns under compression and high temperatures, carrying out a parametric study with 2520 analyses. The results indicate the EN 1993-1-1:2022 [1] standard provides good predictions for carbon steel but underestimates the bearing capacity of stainless steel at room temperature. In fire conditions, EN 1993-1-2:2005 [2] was shown to be insufficient to capture the initial loss of strength of stainless steel, especially in the first phases of thermal exposure, where the resistance capacity dropped by about 10 % in 15 min, compared with a drop of 6 % for carbon steel. After 30 min of exposure, both materials stabilized their resistance capacity, reaching about 80 % and 85 % of the original resistance for stainless and carbon steel, respectively. Longer exposure times to fire produced higher analytical and numerical load capacity ratio values. This study reinforces the need to develop more accurate normative models and adjust current standards to better evaluate the behavior of these structures under compression and fire.