Study On Hysteretic Behavior Of BRB Cantilever Energy Dissipation Truss

Compared with the real-type steel girder,the truss girder has the advantages of low steel content,light and beautiful appearance,especially suitable for large span structure,but the ordinary truss seismic performance is poor,whether it is axial compression or bending,the failure mode are the overall instability,are brittle damage.If the upper and lower chords of the truss are hinged with the vertical members,the lower chords of the end sections are buckled restraining(BRB),and the rest of the bars and joints are the same as the ordinary trusses,forming a BRB type energy dissipation truss structure.It combines the advantages of traditional trusses and BRBs and is an efficient large span seismic steel structure.Based on the previous research results,this paper studies the three parameters of BRB yield bearing capacity,truss height and span.By ABAQUS finite element software,the yield load and yield displacement of the structure are obtained by unidirectional loading method,the hysteresis curve of the structure is obtained by cyclic loading method,at the same time,the ultimate displacement,ultimate load,energy dissipation coefficient and failure mode of BRB energy dissipation truss structure are analyzed.On the basis of the former research results,the hysteretic behavior of the BRB cantilever energy dissipation truss is studied,in view of the shortage of ductile truss structure in the floor and the energy dissipation section combination,the difficulty of implementation and floor load form,this paper presents a new type of two-end just connected energy dissipation truss.With the following advantages:(1)The mechanical model is simple;(2)Elastic stage stiffness,high bearing capacity;(3)Seismic performance;(4)Repairable and strong;(5)Easy to implement;(6)Wide range of applications;Taking the anti-bending point of the upper column as the loading point,On the one hand,it can reflect the static performance of the truss,The reliability of numerical analysis method can also be verified.In this paper,the design method of BRB energy dissipation truss is introduced in detail.the research work is mainly carried out by ABAQUS finite element software,and doing the relevant finite element verification.The results show:(1)In the truss end of the internode between the chord with buckling restraint support(BRB),while the seismic performance of BRB energy dissipation truss structure can be improved remarkably,its energy dissipation capacity and safety reserve are also superior to ordinary truss structure.(2)In the case of the BRB yield and the same BRB yield bearing capacity,the ultimate displacement of the BRB-type energy dissipation truss increases gradually with the increase of the height of the truss and the ultimate load increases with the increase of the height of the truss.(3)The height and the span of BRB energy dissipation trusses have little effect on the energy dissipation coefficient of the structure in the case of BRB first yield and setting the same BRB yield bearing capacity.(4)In accordance with the design requirements of the case,the yield capacity of BRB energy-dissipation section should be increased appropriately,which can effectively improve the capacity of energy dissipation truss structure.At last,based on the analysis results of ABAQUS,the characteristics of BRB cantilever energy-saving truss structure are obtained,in addition,some suggestions are given for the shortcomings of this paper and for future research.