Research On Hysteretic Behavior Of Buckling Restrained Brace And Seismic Behavior Of Braced Steel Frame

In order to reduce casualties and economic losses caused by the earthquake, energy dissipation technology attracted more and more attention in recent years. Buckling restrained brace as an energy dissipation control device has been developed and used in anti-seismic engineering structure for its stable bearing capacity, good energy dissipation ability, convenient installation and other advantages.Based on the study of buckling restrained brace, the paper has made a comprehensive research on buckling restrained brace hysteretic behavior at first, then based on the benchmark model discussed about the buckling restrained braced steel frame seismic performance. The main contents of the paper can be summarized as follows:(1) The paper has introduced the composition and working principle of buckling restrained brace, and made the theoretical analysis of brace stability from the stress mechanism aspect. As meanwhile, the paper summed up a simple and practical design method of buckling restrained brace based on a large number of abroad and domestic research.(2) According to the practical test, using the Zona elastoplastic model, combined hardening model and Bouc-wen model respectively for the numerical simulation of buckling restrained braces. Results show that the hysteresis curve by using Zona elastoplastic model can be almost completely consistent with the test hysteresis curve. In addition, the parameters affected the flow rule and hardening rule of Zona elastoplastic model were analyzed.(3) Based on the benchmark structure model, the simulation model of buckling restrained braced steel frame was completed by using MATLAB/Simulink software, to research the reasonable range of lateral stiffness ratio k between brace and steel frame. Based on a large number of buckling restrained braced steel frame analysis examples, the curves of interstory drift criterion, floor acceleration criterion and base shear criterion under frequent earthquakes varying with different lateral stiffness ratio were established, to determine the reasonable range of k through comprehensive analysis.(4) Based on the optimal lateral stiffness ratio k, the parameters of brace were designed and applied in the benchmark structure. Then executed nonlinear time history analysis under frequent earthquakes and rare earthquakes to compare the earthquake responses of structure under controlled and uncontrolled, and take advantage of evaluation criteria to evaluate the control strategy comprehensively.(5) Under frequent earthquakes, the interstory drift, floor acceleration and base shear of structure have been effectively controlled; under rare earthquakes, the interstory drift criterion, ductility criterion, dissipated energy criterion and plastic hinge criterion were almost all less than 1, indicating that the control strategy played a better damping effect.