The Study Of The Seismic Performance Of The Reinforced Concrete Frame-Buckling Restrained Brace Structure

The buckling restrained brace and the buckling restrained brace reinforced concrete frame has been under theoretical study, analysis and numerical model analysis in this research paper. According to the order from energy dissipation to the damper system,the study has been done.Firstly,proposing a new and innovative BRB as an energy dissipation device for the seismic buildings. The steel yielding core of the BRB is modular, this kind of special design enables the yielding force and the plastic deformation of the buildings can be adjusted by the seismic requirements of the buildings. There are two types which are MBRB1 and MBRB2 displayed in the paper,depending on connecting several Seriate Modules(SM) which are comprised of random number of Shear Basic Dissipation Units(SBDUs),deformation is proportional to the number of the Seriate Modules and force is also proportional to the number of the SBDUs which are on the SM. The assemble of the MBRB includes sliding the greased yielding core into the restraining unit and coupling it with pins, aiming for the easy inspection or the replacement of the brace if it is necessary and required. The main parameters are the yielding force and the yielding displacement which can be predicted and expressed by some simple expressions and equations. To design the restraining unit to avoid the local buckling by taking the initial sway deformation in toconsideration and the functional gap between the yielding core and the restraining unit is also proposed. The hysteretic behavior, force and plastic deformation et al have been simulated with FEM software as ABAQUS.Secondly, the gusset plate in the frame can be subjected to forces not only from the brace but also from the effects of the frame actions. So,several finite element models have been established to analyze the gusset-to-beam and gusset-to-column interface forces. It is found that the frame actions affect the gusset interface force distributions significantly.A simplified strut model to represent the gusset plate is adopted to evaluate the frame action forces. What’s more, the generalized uniform force method is adopted to provide more freedom for designers to configure the gusset plate shapes than using the uniform force method.The gusset interface force demands take into account the combined effect of the brace maximum axial force capacity and the peak beam shear possibly developed in the frame. Based on the coordination of the theoretical calculation and the FEM analysis outcomes, the proposed design procedure has been confirmed to be reasonable and practical. The effectiveness of varying the width of gusset edge stiffeners in reducing the gusset tip stress concentrations is also investigated. And the commendations for the seismic design of BRBF gusset plate has been concluded.Finally, an idealized 10 story reinforced concrete structure with buckling restrained braces is analyzed, and three schemes are defined according to the different arrangement and quantity of the energy dissipation device. In different fortification levels(frequent earthquake and rare earthquake), using the response spectrum method and the dynamic elastoplastic time history analysis method, the simulation analysis of the key parameters such as interlayer displacement, angular displacement, base shear and top displacement and calculation under rare earthquake have been carried out. By between three schemes and parameters derived from the original structure and three schemes of comparative analysis, we can conclude that, under the action of earthquake, the structure set with buckling restrained brace, the interlayer displacement, interlaminar shear and top displacement compared with the original structure are smaller, structural dynamic response under earthquake action has been reduced and the damping effect is more significant. At the same time, the structure of the buckling restrained brace can make the stiffness of the structure increase properly, the damping ratio of the structure under rare earthquake is significantly increased, and the energy dissipation capacity of the structure is increased.The damping effect of the structure mainly depends on the arrangement,quantity and energy dissipation capacity of the buckling restrained brace,and the arrangement of the energy dissipation device can be reduced appropriately by the small earthquake near the top of the structure.