Seismic behaviour of reinforced concrete frame structures with all steel assembled Q195 low yield buckling restrained braces

Abstract

For the traditional buckling restrained braces (BRBs), the core plate is high yield strength steel, and the external restraint system is concrete filled steel tube), it has the disadvantages of high yield strength and large weight, which will produce a large additional effect on the structure. Under the same member deformation, the material with lower strength has larger plastic deformation and more seismic energy absorption, so it is easier to realize the idea that the BRBs is prior to frame structure failure So, an all steel assembled Q195 low yield point buckling restrained braces (LYBRBs), has been proposed in this paper, and the quasi-static low-cycle reciprocating load test was conducted. The results show that the failure mode of the LYBRBS is tensile failure, its hysteretic curve shows good symmetry, stability and fullness, and the LYBRBs has a good energy dissipation capacity. At the same time, based on a reinforced concrete frame (RCF) structure in the area of 8 degree seismic fortification intensity, the RCF structural model was established, and the dynamic characteristics of the RCF structure were compared by PKPM and SAP2000 software to verify the correctness of the model. On this foundation, push-over analysis of the RCF and RCF structure with the arrangement of the LYBRBs (LYBRB-RCF) is performed. The story drift ratio, the curves of the base shear force-top story drift and the plastic hinge condition obtained by push-over analysis are compared. In addition, the structural time history analysis was conducted by SAP2000 software under the action of frequent and rare earthquakes. The story drift ratio, story shear force, time history of the top displacement and acceleration, energy consumption and hysteretic curve of the LYBRBs were analysed.