Experimental and Numerical Study on the Mechanical Behavior of a New Inspectable Self‐Centering Short‐Core BRB Test Model

ABSTRACT This paper presents an experimental and numerical investigation on a new inspectable self‐centering short‐core buckling restrained brace (SC‐SBRB) comprising an SBRB unit for enhanced energy dissipation and a self‐centering (SC) unit equipped with two pre‐compressed disc‐spring stacks. The working mechanism and design of the SC‐SBRB device were discussed in this paper. Half‐scale models of two SC‐SBRBs with different SC ratios, one SBRB, and one SC unit were tested experimentally under cyclic load. The experimental results confirmed stable and nearly symmetric hysteretic behavior of the SC‐SBRB with high ductility and enhanced energy dissipation capacity for a maximum axial strain of 4% in the SBRB core. The core had undergone high‐order restrained local buckling about both weak and strong axes with the increase in axial core‐strain, which contributes to enhanced energy dissipation of the device. The SC‐SBRB test models exhibited flag‐shaped hysteretic behavior with excellent self‐centering capability, minimizing residual deformation by 70%–90%. Further, the SC‐SBRB device provides a convenient inspection facility for rapid damage assessment of the core following any seismic event and also facilitates quick replaceability of the core, if necessary. Numerical simulation of the SC‐SBRB, using a macro model, was performed on OpenSees platform. The hysteretic responses obtained from the numerical simulation were compared with those obtained from the experimental investigation. The results of the numerical simulation and experimental investigation were found in good agreement. The hysteretic responses of the numerical simulation can be used for seismic design of new structures and retrofitting of existing structures with the SC‐SBRBs.