加劲肋对外伸式端板连接节点抗火性能的影响

Fire resistance performance of stiffening rib of extended end plate connections

为研究加劲肋对外伸式端板连接节点抗火性能的影响,结合前人对外伸式端板钢框架连接节点开展的抗火性能实验,采用有限元软件ABAQUS对抗火实验进行数值模拟,并对比分析热-力耦合与热-位移耦合的模拟结果与实验数据。结果显示:在相同的温度、荷载条件下,设置加劲肋后钢框架节点处的最大应力比未设置加劲肋时小。设置加劲肋能够有效提高外伸式端板连接节点的抗火性能,有效抵抗端板"板底脱空"现象对结构所造成的不利影响。加劲肋亦能够有效减小钢框架结构的跨中挠度,大幅度提高钢节点的屈服时间和极限温度。

Thi s paper is aimed at a deeper insight into the effect of the stiffening rib on the fire resistance performance of extended-end-plate steel connection nodes. The study builds on the previous experiments on the fire resistance performance of steel frame nodes of extended-end-plates; uses the finite element software ABAQUS for numerical simulation of the fire resistance experiment; and compares and analyzes simulation results between the thermal-mechanical coupling and heat-displacement coupling on the one hand and the experimental data on the other. The results show that, when exposed to the same temperature and load, the steel frame nodes provided with stiffening ribs have a smaller maximum stress than those not provided with stiffening ribs. The study concludes that the advantages accompanying stiffening rib provision are an effective improvement in the fire resistance performance of the extended-end-plate steel connections, an effective prevention of negative effect of voids beneath concrete slabs on the extended-end-plate structure, a significant reduction in the cross deflection of steel frame structures, and a great increase in yield time and the limit temperature.