| The buckling-restrained brace(BRB)is a new type of energy-consuming support.It solves the problem that common steel supports are prone to compressive buckling,and it can first yield and use energy to protect the main structure under large earthquakes.At present,buckling-restrained brace are mostly used in steel frames,and their application in newly-built concrete frames is less.The study of their seismic performance is also insufficient.The design methods of the existing buckling restrained support frame structures are mostly complicated,which limits the wide application of the structural system.Therefore,in this paper,the seismic performance of the buckling-restrained braced-concrete frame structure is studied in detail,and a more practical design method is proposed to provide reference for the design and application of the buckling constrained braced frame structure.The main research content is as follows:(1)Theoretical analysis of the overall stability of buckling-restrained brace,combined with related research,proposes design methods for the connection of buckling restraint bracing members and their nodes.(2)Under the three types of seismic fortification intensity,6-layer,9-layer,and 12-layer concrete frame models with three layers were designed,according to six kinds of lateral stiffness ratios(0.5,1,1.5,2,2.5,3),Two types of support arrangements(chevron and monoclinic)are used to select and arrange the buckling-restrained brace.Through Midas/Gen's response spectrum analysis under multiple earthquakes and time history analysis under rare earthquakes,the interlaminar displacement angles,bottom shear forces and supporting hysteretic behaviors of the supporting frame structure with the lateral stiffness ratio were studied.According to the relationship of change,it is concluded that the reasonable range of the lateral stiffness ratio of the buckling restrained brace-concrete frame structure is: 0.5 < k <1.5.By comparing the effect of two kinds of bracing arrangements on the seismic performance of the structure,it is suggested that the herringbone arrangement should be used for the multi-story buckling-constrained braced-concrete frame structure;for the high-rise buckling constrained braced-concrete frame structures,both bracing arrangements are Be applicable.(3)Within the reasonable range of anti-side stiffness ratio,take k as 0.6,0.8,1,and 1.2 respectively,and study the relationship between the maximum displacement of the buckling-restrained braced frame structure and the strength of the main frame,and obtain The displacement angle of the main frame under multiple earthquakes.Comprehensively related studies have proposed a method for checking the elasto-plastic deformation of the weak layer of a buckling-constrained brace concrete frame structure,and according to the reasonable range of the values of the inter-story displacement angle and the anti-side stiffness ratio of the main frame structure under multiple earthquakes,according to The design of small earthquakes and large earthquakes are considered.The seismic design method based on the buckling-restrained brace concrete frame structure is proposed.(4)In combination with engineering examples,the structural design was carried out according to the design method proposed in this paper.The static and elastic plastic analysis and dynamic time history analysis were used to verify the practicality and safety of the proposed design method.Comparing the seismic responses of the three structural systems,it is found that the buckling-restrained brace concrete frame structure can significantly reduce the inter-layer deformation compared with the pure concrete frame,control the inter-layer deformation and reduce the layer shear compared to the ordinary steel bracing-concrete frame effectively. |
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