Optimization of the self-centering energy dissipative braces for retrofitting reinforced concrete frames

In this study, an optimization-based design method for retrofitting reinforced concrete frames with self-centering energy dissipative (SCED) braces has been developed. SCED, which has a flag-shape hysteresis, increases the rigidity, strength, ductility, energy absorption capacity of the structures also has ability to prevent permanent damage with self-centering mechanism. An optimization study using the artificial bee colony method was carried out in order to design SCED with lowest cost and highest energy distribution capacity. This study was carried out for six different frames with 1.5, 3, 6 meters spans and 3 meters height, which are loaded axially to represent the ground floor of multi-story structures. The reinforced concrete frames which have insufficient seismic performance according to Turkish Building Earthquake Code- 2018 (TBEC) are selected as providing and not providing strong-column weak-beam conditions. It was concluded that the SCED, which was designed with the optimization study, increased the seismic performance of all the reinforced concrete frames examined and provided the limited damage performance level of TBEC. As a result, it has been shown that reinforced concrete frame-type structures with insufficient seismic performance can be optimally retrofitted with SCED.