FEASIBILITY STUDY OF VISCOELASTIC HYBRID SELF-CENTERING BRACE (VSCB) FOR SEISMIC-RESISTANT STEEL FRAMES

The practicability of existing self-centering braces is largely limited by their small deformability and insufficient energy dissipation. This paper presents a new type of velocity-dependent self-centering brace called viscoelastic self-centering brace (VSCB), which employs viscoelastic dampers (VED) and SMA cables as the kernel elements. The SMA cables can offer large recoverable deformation, and the viscoelastic dampers, which are velocity-dependent, provide considerable energy dissipation under high-frequency loading excitations but tend to have less detrimental influence on the self-centering capability during the shakedown of the system. A comprehensive system-level analysis on three carefully designed prototype buildings was conducted, including a buckling restrained braced frame (BRBF), a pure self-centering braced frame (SCBF) and a viscoelastic self-centering braced frame (VSCBF). The results show that compared with the SCBF, the VSCBF maintains the benefit of small residual inter-story drift (RID) and in addition, exhibits obviously reduced peak inter-story drift (PID) and peak floor acceleration (PFA).