板柱节点火灾中力学性能数值模拟

Numerical Simulation of Mechanical Properties of Slab Column Connections in Fire

为了研究火灾中板柱结构的传热过程及力学性能,模拟分析板柱结构的破坏过程及裂纹开展情况。采用ABAQUS软件对钢筋混凝土建立了相应的传热分析模型和热-力耦合分析模型。数值模拟发现,模型数值模拟值与现场试验值吻合较好;不同受火时间及不同保护层厚度对板柱节点的温度场和极限承载力有不同的影响。结果表明,不同受火时间对板柱节点内温度变化影响非常大,随着构件受火时间的增加构件内温度提高越大;不同的保护层厚度对楼板的钢筋温度值影响非常大,随着保护层厚度的增加,相应的钢筋温度在减小;板柱节点随着受火时间增加,相应的极限荷载在减小;分析了火灾下板柱结构的破坏裂纹扩展情况和应变云图的变化规律,为进一步建立板柱结构整体模型研究受火失效机理奠定了基础。

In order to simulate the heat transfer process and mechanical properties of plate-column structure in fire, the failure process and crack development of plate-column structure were simulated and analyzed. The heat transfer analysis model and thermo-mechanical coupling analysis model of reinforced concrete are established by using ABAQUS software. Numerical simulation shows that the numerical simulation results agree well with the field test values;Different fire time and different thickness of protective layer have different effects on the temperature field and ultimate bearing capacity of slab-column joints. The results show that different fire time has a great influence on the temperature change in slab-column joints, and the temperature increases with the increase of fire time;Different thickness of protective layer has a great influence on the temperature of steel bars in floor slabs. With the increase of the thickness of protective layer, the corresponding temperature of steel bars decreases;With the increase of fire time, the corresponding ultimate load decreases;The failure crack propagation and strain nephogram of slab-column structure under fire are analyzed, which could lay a foundation for further models of slab-column structure and the failure mechanism under fire.