外包不锈钢中空夹层钢管混凝土柱耐火性能研究

为研究外包不锈钢中空夹层钢管混凝土柱的耐火性能，采用ABAQUS对该类组合构件的耐火极限进行了有限元分析。对比分析了外包不锈钢中空夹层钢管混凝土柱与普通外包碳素钢中空夹层钢管混凝土柱受火机理的不同。研究了截面直径、空心率、荷载比和材料强度对构件耐火极限的影响。研究结果表明:外包不锈钢中空夹层钢管混凝土柱比外包碳素钢中空夹层钢管混凝土柱具有更好的耐火性能；该类构件的耐火极限受截面直径和荷载比的影响较大，空心率和材料强度对构件的耐火极限也有一定影响。在参数分析基础上给出了外包不锈钢中空夹层钢管混凝土柱的抗火设计建议。

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.