Study On The Seismic Design Of Buckling-restrained Braced-reinforced Concrete Frame Structures Based On Shear Ratio

In the buckling-restrained braced-reinforced concrete (BRB-RC)frame structures, the design of BRBs is crucial to the seismic performance of the structures. Recent years, researchers around the buckling-restrained braced-reinforced frame structures have proposed different design methods while currently there are still some deficiencies about the system. Wherein, the method based on the energy greatly influenced by the characteristics of the selected seismic motion records, and the complicated calculation is not conducive to widespread use by designers; The range of the key parameter in the method based on the lateral stiffness ratio is too broader, and different researchers give different range of the key parameter, so there are no clear basis for the design of BRB. Therefore, in this study, a method based on shear ratio of BRB-RC system is performed. Then, in order to summarize a kind of simple and suitable design method for the actual engineering which provided reference to the designers, the study have researched about the range of shear ratio and the design of frames.First, this paper introduces the features and design methods of BRB-RC frame structures. Then, the article summarizes the performance characteristics and the mechanical model of BRB. On this basis, the study performs a clear design approach based on the shear ratio, and numerical simulation study on the shear ratio and frame design is derived.Secondly, in order to study the range of shear ratio, the paper design four kinds of concrete frame structures include 6 layers,9 layers,12 layers and 15 layers. For each frame, depending on the value of the shear ratio a (0.1,0.3,0.5,0.7,0.9,1.5,2) BRB set different parameters. Then obtained the relation curve between the maximum story displacement angle of different BRB-RC frame structure under the rare earthquake and the different shear ratio a based on the nonlinear dynamic time-history analyses. At the same time, paper studies the variation of hysteretic energy in a different structure than the shear ratio a at BRB from the viewpoint of energy. Finally, a reasonable range of shear ratio is preferably 0.5<α<0.9.Then, the article further studies the relationship between shear ratio and frame. Fixed shear ratio unchanged, study the maximum drift angle of the overall structure variation with different stiffness change of frame based on a reasonable range of shear ratio. And finally give the frame design suggested values between the maximum drift angle. On this basis, combined with reasonable range of shear ratio, summarized the method and processes based on shear ratio of BRB-RC frame structures.Finally, through the engineering example, to compare the method based on shear ratio and the method based on lateral stiffness ratio. By calculating the comprehensive analysis comparing the two programs, the results show that the two methods designed BRB-RC frame structures compared to frame structure have better performance in control the displacement effect and control the reverse effect under the rare earthquake. However, through the method based on shear ratio, the tonnage of BRB is much smaller, the hysteresis loop of BRB is more full, the energy efficiency of BRB is higher, and the method is also simple to calculate relatively.