Experimental evaluation of large-scale dual-core self-centering braces and sandwiched buckling-restrained braces

Abstract

This paper presents structural characteristics of large-scale dual-core self-centering braces (DC-SCBs) and sandwiched buckling-restrained braces (SBRBs) in a series of cyclic tests. The DC-SCB has a flag-shaped hysteretic response with high axial stiffness and minimal residual deformation, exhibiting a self-centering mechanism. The SBRB as conventional BRBs has much higher energy dissipation capacity than the DC-SCB, but larger residual deformations are expected for structures equipped with SBRBs. The primary objective of the research was to conduct experimental studies that established a direct comparison basis between DC-SCBs and SBRBs designed with similar axial capacity and length. Three SCBs and SBRBs that were about 7.5m long and had maximum axial forces from 1500 to 6000kN were tested to evaluate their cyclic behavior and durability. In general, these tests have shown that the DC-SCB and SBRB exhibit robust cyclic performances with good deformation capacity and durability. The axial elastic and post-elastic stiffnesses of DC-SCB were around two and five times those of SBRB, indicating that the DC-SCB is more effective to resist lateral forces than the SBRB in structures, but the energy dissipation of DC-SCB was around one-third of that of SBRB.