钢框架结构抗火混合试验基本原理及数值模拟

Basic methodology and numerical simulation of hybrid fire testing for steel frame structure

为了研究火灾下整体结构的力学性能,采用抗火混合试验方法仅取局部受火部位进行抗火试验,其余部分通过边界条件进行交互,不仅能考虑火灾下建筑结构的整体作用,而且极大地减小了试验规模,同时依旧保证较好的精度。采用ABAQUS有限元软件建立三层四跨钢框架模型,取单柱作为局部受火子结构模型,进行整体结构的抗火混合试验数值模拟。结果表明:抗火混合试验子结构与整体结构受火柱的温度、轴力、侧向挠度变化基本一致,而柱顶轴向变形仅在后期失稳阶段出现部分偏差,体现了抗火混合试验的准确性和经济性。

In order to study the mechanical properties of the whole structure under fire, the hybrid fire test method is used to take only the local fired part for fire test, and the rest interacts through the boundary conditions, which can not only consider the overall role of the building structure, but also greatly reduces the scale of the test, while still ensuring better accuracy.The ABAQUS finite element software was used to establish a three-layer four-span steel frame model, taking a single column as a local fire substructure model, and numerical simulation of the hybrid fire testing of the whole structure.The results show that the substructure of hybrid fire testing and the fire column of overall structure are basically consistent with the change of temperature, axial force and lateral deformation, while the axial deformation of the column top is only partially deviated in the late stage of instability, which verifies the correctness and economy of hybrid fire testing.