Study On Seismic Energy Dissipation Performance Of Buckling-restrained Brace In Large Cantilevered Steel Truss Structure

The traditional methods of seismic engineering design depend on the intensity,stiffness and ductility of structure.Larger deformation of structure will appear and result in structure damage by using these methods,It will cause serious consequences when structure failure or major component failure on account of overlarge deformation.However,seismic energy dissipation technique is used to dissipate seismic energy and reduce structure seismic response by using additional damping structure and energy dissipation device.Thus,the main structure is protected.Buckling-restrained brace(BRB)which is a kind of new-type seismic energy dissipation component,shows the well load-deformation behavior and higher energy dissipation capacity in both tension and compression,and it doesn't exist stability problem in compression.So the seismic energy dissipation performance of large cantilevered steel truss structure were studied based on a engineering of museum in this paper,and it provided some reference for the seismic energy dissipation design of similar structure.First,the design methods of BRB were expounded and finite element software SAP2000 was used for establishing finite element model of the whole structure on the basis of these methods.Then,the elastic seismic analysis and elastic-plastic dynamic time history analysis was conducted on the structure with common steel brace and with BRB for three different layout respectively.Finally,the calculation under vertical frequent earthquake and vertical rare earthquake was conducted to study the adverse effect of cantilevered end in large cantilevered steel truss under vertical earthquake.The results show that: BRB was still elastic and did not yield under frequent earthquake,its role was similar to common steel brace.When subjected to rare earthquake,BRB yielded first to dissipate seismic energy and protect the main structure effectively.Vibration reducing performance of BRB was better than common steel brace obviously.The effect of large cantilevered end in steel truss structure under vertical earthquake was quite important and it could not be ignored.The seismic performance of BRB was basically the same as common steel brace under vertical frequent earthquake.BRB had more effective control of vertical acceleration and vertical displacement of the cantilevered end than common steel brace under vertical rare earthquake,It could preferably improve the seismic safety performance of large cantilevered steel truss structure.Vibration reducing performance of BRB with vee layout was better than BRBwith herringbone layout and hybrid layout.Nevertheless,BRB with herringbone layout had the best capability of energy dissipation.