Abstract Six fire resistance tests of axially restrained Q690 high strength steel (HSS) columns were conducted in this paper to obtain its fire response and failure pattern. Slenderness, axially restraining stiffness, and load ratios were considered in the tests. The furnace temperature, specimen temperature, specimen deformation, and internal force were recorded during the tests. Furthermore, the critical temperature, fire resistance, failure pattern, and post-buckling behavior were determined based on the test results. Test results showed that increasing the load ratio, axial restraining stiffness ratio, and slenderness would reduce the critical temperature of the specimens. After that, numerical models incorporating residual stress and non-uniform temperature field were developed and calibrated with the test results. Finally, parametric analyses were performed, and a simplified design method was proposed to evaluate the critical temperature of restrained Q690 HSS columns.

中文翻译：

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轴向约束Q690 H型焊接钢柱的耐火性：试验、模拟与设计

摘要 对轴向约束Q690高强度钢(HSS)柱进行了6次耐火试验，获得了其火灾响应和破坏模式。在测试中考虑了细长、轴向约束刚度和载荷比。在试验过程中记录炉温、试样温度、试样变形和内力。此外，根据测试结果确定临界温度、耐火性、失效模式和屈曲后行为。试验结果表明，增加载荷比、轴向约束刚度比和细长会降低试件的临界温度。之后，开发了包含残余应力和非均匀温度场的数值模型，并使用测试结果进行了校准。最后，