Performance Improvement for Steel Structures with Y-Braced Dampers

Steel structures possess high strength and significant ductility, thus areeffective structural forms for earthquake-resistant designs. Structuraldesigns using special moment resisting frames (SMRF) are usuallyconsidered when high ductility is required. In order to improve theseismic performance of the structures, a modified structure adopting kneebraces, namely knee-braced moment resisting frame (KBRF), has beenproposed. This study is focused on the further improvement of seismicperformance for large-spanned steel frames by adopting a new Y-braceddamper system. The Y-braced damper is composed of highly ductileenergy dissipation plate and knee-braced segments. A series of cyclicloading tests will be conducted on the SMRF and Y-braced momentresisting frames with difference arrangement of energy dissipationmechanisms. Test results will be used to evaluate the frame strength,structural stiffness and the structural ductility so that the efficiency ofY-braced damper in seismic performance improvement can be justified.