Seismic Behavior Of Self-centering Buckling Restrained Braces And Scbrb Steel Frames

While conventional earthquake-resisting structural systems c provide adequatelife safety when properly designed, they often rely on significant structural damageto dissipate the seismic energy. The structural damage and the residual drift that mayresult from the inelastic response can make a building difficult, if not financiallyunreasonable, to repair after an earthquake. As a result, development of systems thatreturn to their initial position following an earthquake and minimize structuraldamage is a crucial need. The research presented in this thesis aims to address thisneed by creating an innovative self-centering brace for advanced seismicperformance. To the end, this paper carried out the following tasks.(1) The composition of the structure and assembly methods of self-centeringbuckling restrained brace(SCBRB) are described, calculating its strength, rigidity,stability. And then explain how the brace works, the mechanical properties of thetendons and the self-centering condition of the brace. The performance evaluation isalso given and finially use the software ABAQUS to design and simulate the model.(2) The main parameters of SCBRB are analyzed, respectively choosing theinitial bending, self-centering tendons cross-sectional area, the inner corecross-sectional area, the elastic modulus of the self-centering tendons as theparameters. Analysis shows that SCBRB’s energy dissipation behavior andself-centering performance are not significantly affected by the initial bending.Sectional area of the self-centering tendons can enhance the ability of theself-centering, and the residual deformation becoming smaller. Increasing the innercore cross-sectional area can weak the ability of the self-centering, while theresidual deformation increasing. Reducing the elastic modulus of the self-centeringtendons can lead to fuller hysteresis curve and stronger energy dissipation, but alsogreater residual deformation.(3) The SCBRB modal can be realized by the truss element and non-linearspring paralleling in the structure model. SCBRB steel frame models and BRB steelframe models are built to considered as a comparision.Three multi-case earthquakeground motion records are amplituded to frequent earthquake, rare earthquake, greatearthquake and then applied on the structures for the elastic-plastic time historyanalysis. Displacement reaction of the top floor of the structure, maximum storydisplacement, inter-story drift, base shear and residual deformation were analyzed.Conclutions can be drawn that, SCBRB behavors better in reducing the earthquakereaction as well as residual deformation of the structure than BRB’s.(4) The effection of the four parameters is analyzed of SCBRB, first stiffness,second stiffness, prestress and the inner core cross-sectional area, of the seismicperformance of SCBRBF. First, analyze the effection of single control parameter of SCBRB on the seismic performance of the structure under great earthquake action.Then, by orthogonal experiment design and uniform design determines thecombination of the structure parameters and analyze the effection on the seimicperformance of the structure. Then range and variance analysis are based todetermine the influence order of the parameters on the maximum displacement ofthe top floor, base shear and residual deformation of the top floor. Finally, based onthe analysis results of orthogonal design and uniform design, the regression equationis established between the earthquake response and the influence parameters of thestructure.