Numerical investigation on fire resistance of stainless steel columns with square hollow section under axial compression

• The fire resistance may be simulated by the coupled thermo-mechanical method.
• The influence factors of fire resistance are load ratio, length and eccentricity.
• The formula of bearing capacity at elevated temperature was fitted for column.
• The design methods for fire resistance of column in the code were conservative.

Based on the prior experimental studies on the 6 square hollow section stainless steel columns without axial constraints in fire, the fire resistance performance of stainless steel columns under axial compression was investigated in this paper. The numerical simulation and analysis of the performance of stainless steel columns relative to fire resistance were conducted by the finite element software ABAQUS. The effects of various parameters on the fire resistance performance of the stainless steel columns were studied, focusing on the initial defect amplitude, the load ratio and the length of the stainless steel columns. Referring to the structural fire design methods of stainless steel in the European Code (EN 1993-1-2) and the Euro Inox/SCI Design Manual, the new formulae for ultimate bearing capacity at elevated temperatures were fitted for the axially compressed stainless steel columns. The comparison of fitting results with test results and code results indicates that the fitting formulae are highly accurate and can predict the capacity and critical temperature of the axially compressed stainless steel columns in fire.