Fire resistance of stainless steel beams with rectangular hollow section: Numerical investigation and design

• The influence factors on fire resistance of beam are load ratio and section sizes.
• The capacity of under uniform temperature was related to the strength of material.
• The formula of moment under nonuniform temperature was fitted for the beam.
• The formula for critical temperature of the beam in fire was presented.

Mechanical properties of materials at elevated temperatures are the key factors of structural fire resistance design. Relative to the carbon structural steel, stainless steel has superior stiffness and strength at elevated temperatures. The fire resistant design method for stainless steel beams was investigated based on prior experimental studies on the 6 rectangular hollow section stainless steel beams in a fire. In this paper, the numerical simulation and analysis for the fire resistance performance of stainless steel beams were performed by the finite element software ABAQUS. The effects of parameters on the fire resistance performance of stainless steel beams were studied, which focused on the load patterns, load ratio, span and section sizes (height, width and thickness) of stainless steel columns. Referring to the design methods for fire resistance of stainless steel in the European Code (EN 1993-1-2) and the European Design Manual, the formulae for ultimate bearing capacity and critical temperature were fitted for rectangular hollow section stainless steel beams in a fire. Comparisons of fitting results with test results and code results indicate that the fitting formulae have a high level of accuracy and can predict the ultimate bearing capacity and critical temperature of the rectangular hollow section stainless steel beams in a fire.