STUDY ON THE FIRE PERFORMANCE OF CONCRETE-FILLED DOUBLE-SKIN TUBULAR COLUMNS WITH EXTERNAL STAINLESS STEEL TUBES

To investigate the fire performance of concrete-filled double-skin tubular (CFDST) columns with external stainless steel tubes, the fire resistance of this kind of composite members was analyzed by ABAQUS. The differences in the fire mechanisms between CFDST columns with external stainless steel tubes and those with external carbon steel tubes were studied. The effects of the cross-sectional dimension, hollow ratio, load ratio and material strength on the fire resistance of components were analyzed. The results show that the CFDST columns with external stainless steel tubes present better fire resistance than those with external carbon steel tubes. The fire resistance of members was greatly affected by the cross-sectional dimension and load ratio. The hollow ratio and material strength had a moderate influence on the fire resistance of the members. Based on a parametric analysis, a design method for the fire safety of CFDST columns with external stainless steel tubes was suggested.