Seismic performance of buckling-restrained braced steel frames subjected to earthquake main shock-aftershock sequences

Abstract

Recently, there are many papers report the development of some new buckling-restrained braced (BRB) frames and the evaluation of its characteristics. At the same time self-centering buckling-restrained braced (SCBRB) frames are considered as new solutions for the increasing of the structural resilience. In this thesis, the seismic performance of structures is analyzed subjected to earthquake main shock-aftershock sequences. There is comparison of two types of the additional BRB elements, and also there is comparison between them and original steel frame to show the effect of using BRB and SCBRB elements. To compare the seismic performance of BRBF and SCBRBF, the same main shock-aftershock sequences were used in this part. Because of the flag-shaped hysteretic curve of the SCBRB elements, big amount of the energy was dissipated during the motion. Compared to steel frame, smaller seismic responses and residual deformation occurred the structure. BRBF and SCBRBF can control the seismic responses effectively due to the energy dissipation of BRB, and SCBRB can also reduce the structural residual deformation. The earthquake aftershock after earthquake main shock can increase the structural damage and enlarge the structural seismic responses.