Seismic tests of full-scale two-story steel frames with self-centering braces and buckling-restrained braces
Journal
11th National Conference on Earthquake Engineering 2018, NCEE 2018: Integrating Science, Engineering, and Policy
Journal Volume
8
Pages
5223-5233
Date Issued
2018
Author(s)
Abstract
A steel dual-core self-centering brace (DC-SCB) has both re-centering and energy dissipation properties in earthquakes, reducing residual deformation of a frame structure. Past works showed that the DC-SCB performs satisfactorily in seismic tests as the buckling-restrained brace (BRB). In this work, three-story steel frames with single-diagonal DC-SCBs and BRBs were designed; three full-scale two-story, one-bay steel frames that had DC-SCBs and BRBs were tested. Multiple tests of the 9 m-wide, 7.54 m-high braced frames focused on: (1) validating the system response with DC-SCBs, BRBs and a mixed brace configuration, (2) studying the force distribution in framing members, and (3) investigating the replacement characteristics of the frame. The subassembly frame specimens performed well up to an interstory drift of 2%, with yielding in the brace, column and beam. No damage of the DC-SCB or BRB was observed, but fracture of the steel beam flange near the intersection of the web stiffener and gusset plate occurred due to low-cycle fatigue loading. The lateral stiffness, residual deformation and energy dissipation were used to evaluate braced frame specimens in multiple tests. In contradiction to a single brace test, the energy dissipation of the two-story frame specimen with DC-SCBs is higher than that with BRBs due to large lateral stiffness and strength. Nonlinear time history analyses were also performed on the prototype braced frames to obtain seismic demands. ? NCEE 2018.
Subjects
Buckling; Deformation; Earthquake engineering; Energy dissipation; Engineering geology; Seismology; Steel construction; Steel testing; Stiffness; Testing; Buckling restrained braces; Force distributions; Lateral stiffness; Low-cycle fatigue loading; Nonlinear time history analysis; Residual deformation; Steel beam flanges; Subassembly frame; Structural frames
Type
conference paper