Performance-based seismic design and vulnerability assessment of concrete frame retrofitted by metallic dampers

Concrete frame has been one of the most widely employed structural types in engineering practice and would also have widespread application in the future. However, severe failure even collapse behavior were also detected for the pure concrete frame in strong earthquakes. So it is necessary to improve the seismic performance of pure concrete frame. This paper aims to analyze the seismic performance of metallic damper retrofitted concrete frame. Three concrete frames with metallic damper were selected as the research objects. The performance-based seismic design using the equivalent energy method was employed to design the prototype buildings, in which the multi performance objectives were considered. The concrete beam and column was designed taking the additional forces caused by the metallic damper into consideration. Further, the numerical model of the concrete frame with metallic damper was developed and verified by the test results. Time-history analyses were performed under frequently-occurred, design-based and maximum considered earthquakes to validate that the seismic performance of prototype buildings complied with the design objectives. Subsequently, seismic vulnerability of three prototype buildings were evaluated in terms of non-collapse and collapse fragilities. The analytical results indicated the performance-based design method is suitable to design the concrete frame with metallic dampers and the metallic damper could significantly improve the seismic vulnerability of pure concrete frame. This paper is beneficial for the design and application of metallic damper in concrete frames.