分段装配式防屈曲支撑螺栓连接方法研究

Assembled buckling-restrained braces have advantages of easy disassembly, precise manufacturability, and light weight. However, conventional buckling-restrained braces often face challenges in conducting rapid post-earthquake damage assessment and typically require integral disassembly to replace localized damaged components. A segmental assembled buckling-restrained brace (SA-BRB) is proposed to address this issue, which facilitates post-earthquake visual inspection and localized replacement of damaged components after an earthquake. By establishing a simplified equivalent beam model of SA-BRB bolted connection, the relationships among the steel core contact force, bolt prying force, and bolt axial force are determined. Additionally, a bolted connection method for SA-BRBs is proposed, and the axial force calculation formula for the SA-BRB bolts is fitted and determined based on finite element simulation results. The results indicate that key parameters such as channel steel flange height, thicknesses of channel steel flange and web, the widths of cover plates, shim plate and inner core, and bolt spacing significantly influence the bolt prying force coefficient. These parameters, compared to the midspan bolted connections, exhibit a greater amplifying effect on the prying force in end bolt-connections. It is recommended to consider a bolt axial force amplification factor of 1. 1 in the design, with a longitudinal bolt spacing of 100 - 200 mm. The proposed design method effectively predicts the failure modes of SA-BRB bolted connections and provides theoretical references for research and design methodologies related to buckling-resistant braces.