A study on the mechanical properties of the open-closable BRB for reinforcing weak-storey structures

Traditional methods of reinforcing weak storeys increase the lateral stiffness and strength of the original structure, potentially causing damage to non-structural components. This paper proposes an open-closable BRB (OCBRB) based on BRB energy dissipation, which utilizes lateral displacement without altering the structure's initial stiffness. Designed for reinforcing weak storeys, the OCBRB offers adaptability and protection. To investigate the mechanical performance of OCBRB-reinforced structures, a mechanical model was created and its stress characteristics analysed. Three scaled specimens were designed and subjected to quasi-static testing to examine how gap sizes and initial angle influence the mechanical behaviour of the reinforced structures. A simplified restoring force model that shows strong consistency with the results of experiments was successfully developed for the OCBRB-reinforced structure. Finally, the theoretical basis for designing key OCBRB parameters was established by deriving calculation formulas for the initial angle and gap.