为研究屈曲约束支撑 (buckling-restrained brace, BRB) 及其体系在高温工况的抗震性能, 对 BRB 芯材低屈服点 LYP160 钢材分别进行了常温和高温材料力学性能试验. 通过与试验结果比较, 建立了 BRB 热-力耦合精细化有限元分析模型, 验证了该模型的准确性; 对火灾下 LYP160 屈曲约束支撑的温度场、滞回曲线、骨架曲线和耗能能力等性能进行了对比分析; 对不同工况(3 种火灾工况和常温工况) 下8 层配置屈曲约束支撑钢框架(BRB structure, BS) 和原结构 (original structure, OS) 分别进行了弹塑性动力时程分析. 研究结果表明: 3 种火灾工况下 BS 的平均层间位移角较于 OS 分别降低了 30.4%、33.2% 和 42%; OS 柱塑性铰损坏严重, 且更多出现在柱上, BS 整体损坏程度较 OS 轻, 更为安全可靠.

To study the seismic performance of buckling-restrained braces (BRBs) and the corresponding system at high temperatures (i.e., concerning fire), the mechanical properties of the BRB core material were tested at room and high temperatures. Considering the test results, a refined thermomechanical coupling finite element model of a BRB was established and the accuracy of the model was verified. Additionally, the performance of temperature field, hysteretic curves, skeleton curves, and energy dissipation capacity of an LYP160 BRB under conditions resembling fire were compared and evaluated. Elasto plastic dynamic time analyses were separately conducted regarding a BRB with an 8-story steel frame structure (labeled as BS) and the original structure (OS) under various conditions: three high-temperature ranges (like fire) and room temperature. The results showed that the average inter-story drifts of the BS under the three heat conditions were 30.4%, 33.2%, and 42% lower than that of the OS. There are severe damage of plastic hinges on the OS, more occurring in the column, while the overall damage of BS was less severe. Thus, the BS is safer and more stable than the OS.