Experimental study on the buckling restraint brace of low yield point steel 160 at different temperatures

• Published in: Engineering structures 2024-12, Vol.320, p.118878, Article 118878
• Main Authors: Hu, Baolin, Xu, Yuhao, Zhai, Mingjiang, Wang, Changhong, Hu, Wubiao
• Format: Article
• Language: English
• Subjects: Buckling restraint brace; Energy dissipation performance; High temperature; Low yield point steel; Overall stability
• ISSN: 0141-0296
• DOI: 10.1016/j.engstruct.2024.118878

In industrial buildings, the internal operating environment of the structure is complex and there are different high-temperature conditions. Buckling Restrained Brace (BRB), as a common hysteretic metal damper, provided an additional lateral stiffness to the structures under frequent earthquakes when BRB remains elastic and yielded to dissipate the seismic energy under rare earthquakes. Due to the complexity of high temperature and seismic coupling effect, it is imperative to acknowledge the significance of energy dissipation capacity and stability of BRB under different high-temperature conditions. Consequently, the behavior of BRB at different temperatures has been studied. Low Yield Point (LYP) steel 160 is used as the core plate, and three full-scale BRB specimens are subjected to low-cycle repeated load tests at various temperatures. The BRB specimens are compared and analyzed in terms of the hysteretic characteristic and seismic energy dissipation under different temperatures. The results show that the hysteresis curves of BRB exhibits a full and stable shape. Under the three conditions. Cumulative plastic deformation and the ductility coefficient of maximum displacement exceeded the threshold in all the cases, which demonstrates a significant plastic deformation capacity and ductility performance. Finite element software ABAQUS was used to study the heating and cooling process of the BRB, and the hysteretic performance under the action of thermal-mechanical coupling effects is taken into account. The parametric analysis is verified comparably of the BRB by the different lengths and yield capacities under high temperatures. Finally, the design method of LYP steel 160 BRB is put forward to ensure safety against earthquakes and high temperatures. •Low Yield Point mild steel 160 Buckling Restrained Braces are tested at ambient temperature, 121 ℃ and 226 ℃ respectively.•Comparison between energy dissipation and damping capacities of BRB under ambient temperature, 121 ℃ and 226 ℃ are drawn.•Temperature, yield load and support length are selected as the impact factors to analyze the BRB behaviors.•Bearing capacity design formula of LYP mild steel 160 BRB at high temperatures is proposed.