Seismic behavior of an X-deployed cable-braced bolt-assembly steel frame

摘要

Steel cable with its superior performance is used in steel structure as a brace. An X-deployed cable-braced bolt-assembly steel frame (CBBSF) was proposed. The seismic behaviors of an unbraced moment-resisting bolted steel frame (BSF) and four pairs of CBBSFs were tested and analyzed by the finite-element model under cyclic load. The steel frames of CBBSF arc the same, while the cables have the same sectional area in each pair and have varying sectional areas between different pairs. In each pair of CBBSF including CBBSF-F and CBBSF-W, the cables of CBBSF-F are pre-slacked, while the cables of CBBSF-W are not pre-tensioned or pre-relaxed. A formula for the lateral stiffness of the CBBSF was proposed. The hysteresis performance, strength, ductility, stiffness, self-centering capability, and failure mode of the CBBSFs were obtained and compared with each other and with the BSF. The influence of the cable sectional area and pre-slack on these behaviors was obtained. It was found that CBBSFs exhibit reasonable hysteresis performance, energy dissipation capacity, self-centering capability, and have large stiffness and strength. The hysteretic performance and energy dissipation capacity of CBBSF is better than BSF. The CBBSF with a larger cable sectional area has better self-centering capability. The energy dissipation capacity and ductility increased initial ly with the increase of cable sectional area, then, followed by a subsequent decrease. The cable pre-relaxation decreased the maximum cable force to avoid break, increased the yield displacement, ultimate displacement, and ductility of CBBSF, and slightly decreased the yield and ultimate strength. (C) 2020 Elsevier Ltd. All rights reserved.