Numerical and experimental investigation on seismic behavior of the linked column steel braced frame system with energy-dissipating link beam at column base

The linked column braced frame (LCBF) system features a braced frame system coupled with the linked column. The interior column base was uplifted and connected to the ground via an additional link to further improve link ductility and energy dissipating capability. Low cyclic loading tests were conducted on a three-story, one-bay, one-third-scale specimen. Results showed that plastic hinging was successfully limited to the links for a wide drift range. Damaged links were replaced with another type, and system performance was regained. The specimen was loaded again until structural failure, which was induced by damages occurred in links and fixed column bases. Hysteretic curves were plump for both link types, system lateral stiffness degraded slowly, and high bearing capacity was maintained during the whole loading process. Parametric analyses were then conducted numerically based on models validated by test data. The length of link with web stiffener was recommended to be within (1.0-1.5)M-p/V-p, where M-p and V-p were the plastic moment and plastic shear force, respectively. Experimental and numerical results have demonstrated the proposed LCBF system not only with high bearing capacity and significant energy dissipation, but also capable of achieving performance objectives including rapid return to occupancy and collapse prevention.