Experimental Study And Theoretical Analysis Of Joints Between Buckling-restrained Brace And Reinforced Concrete Frame Under Seismic Action

Buckling-restrained brace(BRB)is one of effective means to realize energy dissipation,which can improve the stiffness,bearing capacity and realize energy dissipation of frame structures.At present,most studies focus on the performance innovation of BRB and effect of BRB on seismic behavior of steel frame or CFST column composite frame.However,the research on the effect of BRB on seismic behavior of reinforced concrete(RC)frame is limited.In order to investigate the influence of different connection types on seismic performance,failure modes and working mechanism of connections between BRB and RC frame,some quasi-static tests were performed on five BRB-RC frame joints.Theoretical analysis was presented based on the experimental results.In addition,finite element(FE)analysis and parameter analysis were carried out.The main research was summarized in detail as follows:(1)Five BRB-RC frame joint specimens under horizontal low-cyclic loading were conducted,and research parameter was the connection type between BRB and gusset plate.A detailed account of hysteresis behavior and failure modes of BRB-RC frame joint were discussed and compared on different connection types.(2)The seismic performance of five BRB-RC frame joint specimens was estimated in terms of ductility,strength and stiffness degradation,and energy dissipation capacity,etc.The working mechanisms of this structure and yield order of the components were analyzed on the basis of rotation deflection and strain variation.(3)The FE model of BRB-RC frame joint was established by using ABAQUS software.Horizontal load(P)-horizontal displacement(Δ)curves were recorded and analyzed.Compared with the experimental data,the accuracy of this model was evaluated.Besides,the nonlinear full-range analysis of two specimens was carried out,and the failure model and stress distribution law of the key components were discussed.(4)The simplified calculation model of BRB-RC frame joint was established by ABAQUS software and the accuracy of this model was verified.Based on a single layer-single span frame in practical engineering,the influences of gusset plate steel yield strength,concrete strength,longitudinal reinforcement grade,gusset plate thickness,aspect ratio,axial compression ratio and type of beam loading distribution on the mechanical behavior of BRB-RC frame were discussed respectively.