轴心受压双钢管混凝土柱火灾后剩余承载力的研究

Study on Load-Carrying Capacity on or after Exposuring to Standard Fire of Concrete-Filled Double Steel Tubular Columns

研究了双钢管混凝土柱耐火承载力以及火灾后的剩余承载力。通过选取合适的钢材与混凝土热工性能模型,在有限元程序中模拟了ISO-834标准火灾升温曲线下双钢管混凝土柱的截面升温过程,得出了截面温度场分布以及不同部位的升温过程曲线。在此基础上结合钢管、混凝土高温下以及高温后的应力-应变本构模型分别对高温下与高温后轴心受压双钢管混凝土短柱进行了受力全过程数值分析,得到了高温下(后)轴心受压双钢管混凝土短柱的受力特点。

The load-carrying capacity on or after exposuring to standard fire of concrete-filled double steel tubular short columns are studied in this paper. By selecting suitable thermal properties of steel and concrete, the temperature-time curve of the cross section and the temperature distribution of column exposed to the ISO834 standard fire is obtained. Based on the simulation results, the numerical computation of concrete-filled double steel tubular columns subject to axial compression is done by considering suitable stress-strain relationship of steel and concrete on or after fire. The analysis results show that the highest temperature and the diameter of inner steel tube are the primary inference factors of the fire resistance capacity.