Analysis Of Influence Of Buckling-Restrained Brace Form On Seismic Performance Of Frame-Cylinder Structure

As a very important structural form in high-rise buildings,frame-core tube structure has attracted much attention for its seismic performance.The application of bucklingresistant braces can make the overall force of the structure more reasonable,which can solve the sudden change of stiffness along the height of the frame-core tube structure caused by the reinforced story,and can effectively reduce the lateral displacement of the structure.Buckling-proof braces are more and more used in engineering practice because of their hysteretic energy dissipation,convenient construction and economic rationality.However,in practical engineering applications,the arrangement of energy dissipation and shock absorption devices in the strengthened layer outrigger truss will cause stress mutation along the height direction of the structure,resulting in weak layers and affecting the overall force of the structure.In this paper,combined with practical engineering,the seismic performance of frame-core tube structure with strengthened story outrigger truss as buckling brace is explored,and the relative optimal layout scheme is obtained,which has great practical significance.In this paper,ETABS finite element software will be used to analyze the actual project of a frame-core tube structure in Shenzhen.Firstly,the original structure with an outrigger truss reinforcement layer is studied,and then the multi-channel reinforcement layer layout model is established.By changing the layout form of the outrigger truss(herringbone,triplefold line,double-line)and related materials(common steel support,buckling-resistant brace),the outrigger layout form which is most conducive to the seismic performance of the structure under various layout forms is explored.Then,by setting up a number of comparative experiments,the influence of the height of the multi-channel extensor on the structure is analyzed.Finally,the elastic-plastic time history analysis of the structure is carried out to study the influence of the arrangement of buckling-resistant braces on the energy dissipation of the structure under the rare earthquake.Through the experimental analysis,it can be concluded that the substitution of buckling-resistant braces for ordinary steel braces will not have a greater impact on the natural vibration period and the base shear force of the structure.An extension arm is arranged at 0.6H of the structure,and the seismic performance of the structure with threefold line bracing is relatively optimal.When the outrigger truss of two reinforced stories is arranged at 0.4H/0.8H,the herringbone arrangement has the best seismic performance.When the three outriggers are arranged and located at 0.4H/0.7H/1H of the structure,the three-fold line is the relatively optimal scheme.The arrangement of anti-buckling braces in the outrigger truss of frame-tube structure can effectively reduce the overall damping energy of the structure,improve the total hysteretic energy dissipation of the structure,and effectively reduce the response of the structure to seismic action.