Influence of hysteretic dampers on the seismic response of reinforced concrete wide beam-column connections

摘要

This research investigates the seismic performance up to collapse, and the ultimate energy absorption capacity of, existing nonductile reinforced concrete frames with wide beam-column connections seismic upgraded with brace-type hysteretic dampers. Four 2/3 scale exterior and interior connections with and without brace dampers were constructed and tested in a shaking table. The hysteretic dampers were designed so as to increase the lateral stiffness of the connection by ten times, and to limit the maximum interstory drift below 0.7% of the story height. The test models were subjected to a series of seismic simulations of increasing peak ground acceleration until collapse. The brace dampers reduced the maximum interstory drifts by 60%-80%, and increased the ultimate energy dissipation capacity of the exterior and interior connections by 12 and 4 times respectively. The RC elements of the connections equipped with brace dampers remained in nearly elastic conditions (i.e. with minor damage) until one of the brace dampers failed.