Performance of Y-Braced Steel Frames Subject to Near-Fault Ground Motion

Steel structures possess high strength and significant ductility, thus are effective structural forms for earthquake-resistant designs. Structural designs using special moment resisting frames (SMRF) are usually considered when high ductility is required. In order to improve the seismic performance of the structures, a modified structure adopting knee braces, namely knee-braced moment resisting frame, has been proposed. This study is focused on the performance evaluation of Y-braced moment resisting frames subject to near-fault ground motion. The Y-braced damper is composed of highly ductile energy dissipation plate and knee-braced segments. A series of tests will be conducted on the SMRF and Y-braced moment resisting frames with different arrangement of energy dissipation mechanisms subject to near-fault loading protocol. Test results will be used to evaluate the frame strength, structural stiffness and the structural ductility so that the efficiency of Y-braced damper in seismic performance improvement can be justified.