矩形钢管混凝土翼缘梁与柱节点的火灾滞回性能

Hysteresis performance investigation of the joints of RCFSTF beams and column in fire

地震时火灾往往对钢结构力学性能产生严重影响,因此钢结构耐火是结构领域研究热点。为了研究矩形钢管混凝土翼缘工字梁与柱节点火灾过程中滞回性能,根据标准升温曲线ISO834,对矩形钢管混凝土翼缘工字梁与柱节点、纯钢节点进行热力耦合数值模拟,得到了火灾中的滞回性能。研究结果表明:滞回曲线随温度升高越来越水平,塑性出现越来越早;升温过程中,矩形翼缘组合梁节点的滞回性能优于纯钢节点;钢材和混凝土性能受温度变化影响机理不同,应加强上翼缘钢管的耐火方法研究。由上述结果得出:对于处于高烈度区有火灾隐患的结构可采用矩形翼缘组合梁,且应加强矩形翼缘组合梁耐火的深入研究。

The mechanical properties of steel structures are often influenced seriously in fires induced by earthquake, so fire resistance of steel structures is a hot-spot in the field of steel structures. In order to investigate the hysteresis performance of the joint of rectangular concrete-filled steel tube top flange I-beam (RCFSTF beam) and steel column in fire, the thermal-mechanical coupling simulation was conducted for this kind of joints according to standard time/temperature curve ISO834, and the same was done for pure steel joint. The results show that: the hysteresis curve becomes more and more horizontal with increasing temperature, and the plasticity appears earlier and earlier;the hysteresis performance of the joints of RCFSTF beams and column is better than that of pure steel joints during the heating process;the influence of temperature on the properties of steel and concrete is different, so the study for the fire resistance of upper steel-tube flange should be strengthened. It is concluded that rectangular RCFSTF beam can be used for the structure in high earthquake intensity region with fire hazard, and the fire resistance of this kind of beam should be further investigated.