EXPERIMENTAL EVALUATION OF NONLINEAR REPLACEABLE LINKS IN ECCENTRICALLY BRACED FRAMES AND MOMENT RESISTING FRAMES

摘要

While steel EBF and MRF structures designed according to the current seismic design specifications can provide life safety during a design level earthquake, they are expected to sustain significant damage through repeated inelastic deformation and localized buckling. The design of the yielding elements is also interlinked with the design of the connecting beam, which often results in a significant over-design. These drawbacks can be mitigated by introducing nonlinear replaceable links at the locations of expected inelastic action. Ten full-scale links were tested at the University of Toronto following incremental cyclic loading protocols for verification of strength and ductility: six shear links for EBFs and four flexural links for MRFs. Two link types were tested for each system: i) back-to-back channels bolted to the web of the connecting beam, ii) W-sections with end plate connections. All end plate links provided good performance and energy dissipation. The channel links exhibited an improved ductility upon improvement of the web connection design.