Optimization Of Buckling-Restrained Brace For Frame-corewall Structure

As a new energy-consuming member,the buckling restrained brace can simultaneously be competent for both supporting components and dampers,thus fully dissipating seismic energy and improving the deformation ability and anti-collapse performance of the structure.In the super-high-rise structure,the vertical uniform arrangement buckling restrained brace is usually adopted,although the layout method takes into account the uniformity of vertical stiffness distribution,but the cost is too high and at the same time the structure increases the load,which affects the popularization and use of buckling constraint support.Reasonable arrangement of buckling restrained brace in some floors of the structure can not only improve the seismic performance of the whole structure,make the overall structure deformation and force uniform,but also give full play to the advantages of buckling constraint support,with less support to achieve the best damping effect.In this paper,the actual reinforced concrete frame-core tube structure is selected as the engineering background,the finite element model is established by using SAP2000 finite element analysis software,and the rationality of modeling is analyze.The buckling restrained brace is arranged on some floors,and the seismic performance of the structure is compared and analyzed by the static vibration decomposition reaction spectrometry and the Dynamic Time history analysis method,and the buckling restrained brace is arranged at different floor positions,the arrangement of different numbers and the transformation of different forms of the scheme.The optimal arrangement scheme of buckling restrained brace for reinforced concrete frame-core tube structure is determined,and the elastoplastic time history analysis of the optimal arrangement scheme is carried out,and the following conclusions are drawn:(1)The buckling restrained brace is arranged reasonably in the structural part of the floor,which improves the stiffness of the structure but has little effect on the period and quality,reduces the deformation of the whole structure,and does not appear the weak layer,which makes the whole structure uniform force;Under the action of different seismic waves,the original structure has a floor which does not meet the requirements of the standard limit of interlayer displacement angle,and is gradually optimized after the buckling restrained brace is arranged reasonably,until the displacement angle between all floors of the optimal scheme meets the requirements of the specification.(2)In this paper,the reinforced concrete frame-core tube structure on the ground 26 layers,the analysis results show that the buckling restrained brace of the optimal layout of the floor position at the third or fourth floors,that is,in the total height of the house 1/6?1/8.At the optimal floor position,eight buckling restrained brace is arranged evenly and symmetrically in four corner positions,which can effectively reduce the structural deformation and the best damping effect.(3)The optimal arrangement scheme of buckling restrained brace is to arrange 8 support symmetrically at four corners at the optimal floor position.The upper V-shaped inverted V-shaped integral X-shaped arrangement can reduce the displacement angle of the maximum interlayer by 27.864%,the maximum reduction of the floor shear force 9.637%,indicating that the two layer arrangement is the X-shaped energy to maximize the support of the damping effect.(4)Under the action of rare earthquake,elastoplastic time history analysis is carried out for the optimal buckling restrained brace arrangement scheme,which mainly includes interlayer displacement angle,vertex displacement time curve,basement shear time curve,substrate shear force etc.It is concluded that the interlayer displacement angle of the optimization scheme meets the requirements of standard limit value,the structure has strong deformation ability and safety reserve.The elastoplastic substrate shear force is smaller than the base shear force of elastic model under large earthquake,and the energy dissipation of buckling restrained brace is fully utilized,which reduces the seismic response of the structure under the action of large earthquake and increases the safety...