Experimental investigation on the fire resistance of restrained stainless steel H-section columns

Abstract

To investigate the failure mechanism of restrained stainless steel H-section columns under axial compression during fire exposure, the mechanical properties of S30408 (EN1.4301) austenitic stainless steel at normal and elevated temperatures were obtained by the tensile tests, and 7 restrained stainless steel H-section columns under axial compression were tested in fire. By high temperature steady-state test, the elastic modulus, ultimate strength, yield strength and stress-strain curve under different temperatures were obtained. Comparing on the mechanical properties of stainless steel at normal and elevated temperatures, the mechanical property reduction factors under different temperatures were proposed. The influences of axial/rotational restraint stiffness ratio, load ratio and slenderness ratio on the fire resistance were analysed. The failure modes, temperature curves, axial displacement curves, mid-span lateral displacement curves, buckling temperatures and critical temperatures of the specimens were presented. The result shows that axial/rotational restraint stiffness ratio, load ratio and slenderness ratio all have great influences on the fire resistance of restrained stainless steel H-section columns under axial compression.