Hysteretic performance of structural steels after exposure to elevated temperatures
Hysteretic performance of structural steels after exposure to elevated temperatures
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DOI：
10.1016/j.tws.2023.111019
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发表时间：
2023-10
影响因子：
6.4
通讯作者：
Wei Li;Hao Chen
中科院分区：
文献类型：
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作者：
Wei Li;Hao Chen
本文介绍了普通强度和高强度结构钢在高温下的滞回特性的实验和分析研究。试验参数包括所经历的最高温度、冷却方式和加载方案。通过金相分析研究了高温暴露后的显微组织变化。试验结果表明，Q355和Q620钢在空气中冷却后的屈服强度分别下降了21%和45%；而能耗能力则分别下降25%和42%。对于水中冷却的试样，当应变水平为0.6%时，Q355的能耗能力提高了39%，而在相同应变水平下，Q620的能耗能力下降了21%。通过回归分析，建立了钢在高温下的滞回模型，并根据实验数据对关键系数进行了校正。提出的模型很好地反映了普通钢和高强度钢在高温下的滞回行为，为钢结构火灾后的抗震性能评估提供了依据。
This paper presents both experimental and analytical investigations on the hysteretic behaviour of normal strength and high strength structural steels after being exposed to elevated temperatures. The test parameters include the highest temperature experienced, the cooling method and the loading protocol. The metallographic analysis is conducted to study the change of micro structure after elevated temperature exposure. The test results show that the yield strength of Q355 and Q620 steels cooled in the air decreases up to 21% and 45%, respectively; while the energy consumption capacity decreases up to 25% and 42%, respectively. For specimens cooled in water, the energy consumption capacity of Q355 increased by 39% when the strain level was 0.6%, while that of Q620 decreased by 21% at the same strain level. A hysteretic model for steels after being exposed to elevated temperatures is proposed by regression analysis, where the key coefficients are calibrated from the experimental data. The proposed model captures well the hysteretic behaviour of both normal and high strength steels after exposure to elevated temperatures, which provides the basis for the post-fire seismic performance assessment of steel structures.