Study on the seismic performance of high-strength steel framed-tube structures with replaceable shear links

Abstract

In this paper, a high-strength steel framed-tube structure with replaceable shear links (HSS-FTS-RSL) was proposed to improve the seismic performance and recoverability of steel framed-tube structures (SFTS), by introducing the shear link—acting as a sacrificial component—at the mid-span of a deep beam in order to sustain inelastic deformation and dissipate seismic energy. The preliminary design methodologies for the HSS-FTS-RSL and layout principles of the replaceable link were introduced. Six prototype 30-story HSS-FTS-RSL buildings with various layouts of the links and a corresponding conventional SFTS building were designed based on the latest design standards, and their nonlinear numerical models were developed in OpenSees. The modeling approach was verified on experimental data. Nonlinear dynamic analyses were conducted to investigate the feasibility and seismic behavior of HSS-FTS-RSLs. The results indicate that the HSS-FTS-RSL exhibited a superior energy dissipation capacity and lower permanent drifts compared with the conventional SFTS under severe ground motions. In the HSS-FTS-RSL, employing the shear link did not increase the shear lag effect compared with the SFTS. The HSS-FTS-RSLs with various layouts of replaceable links had almost identical fundamental natural periods, but the layout of the replaceable link had a significant effect on their seismic behavior. The inelastic deformation of HSS-FTS-RSL was concentrated in the shear links, whereas deep beams and columns experienced minor or no damage. Therefore, it can be concluded that the HSS-FTS-RSL was a reliable earthquake-resilient structural system that can be quickly recovered by replacing the damaged links after a major earthquake.