The Research On Performance Of New Notched H-Section Assembled Buckling-Restrained Brace

Buckling-Restrained Brace is a good energy-consuming component meanwhile it has double functions of ordinary support and metallic dampers.The buckling-restrained brace can dissipate earthquake energy through mild steel yielding under strong earthquakes and only serves as common support to provide lateral stiffness for the structure under small earthquakes.At the same time,the buckling-restrained brace is increasingly used to new or reinforcement engineering on account of low production cost,simple installation,flexible layout,convenient installation,etc.There are many types of buckling-restrained brace and each has its own advantages and disadvantages.The stability of concrete filled steel tube buckling-restrained brace is better but it has many disadvantages such as larger weight,long construction period and poor machining accuracy.However,pure steel buckling-restrained brace can overcome these disadvantages,but it is faced with the problem of instability and failure of support.So this paper made the following works to solve these problems:Firstly,the present situation of domestic and foreign research and engineering application of buckling-restrained brace are introduced.Then a new notched H-Section assembled buckling-restrained brace is proposed in this paper.The new buckling-restrained brace has some advantages as the following:(1)It has the characteristics of low self-importance,short production cycle,high machining precision and stable performance.(2)It can solve the problem that buckling-restrained brace end is easy to damage with designated yield location.(3)The check after earthquake and replace the kernel component of buckling-restrained brace is easy because of the assembled structure is adopted.Secondly,some problems of new buckling-restrained brace are analyzed with theory in this paper,such as overall and local stability,local stability of the H-Section kernel and the value range of brace clearance.What’s more,the conditions of structural stability and the value range of brace clearance are obtained.Thirdly,the bearing capacity and hysteretic behavior of the new buckling-restrained brace are studied with finite-element analysis software by using ABAQUS.And many design parameters impacted on bearing capacity and hysteretic behavior are discussed.These parameters include brace clearance,slot depth,slot number,slot length and confinement ratio etc.Finally,some suggest value ranges of these parameters are presented.Lastly,the new notched H-section assembled buckling-restrained brace is applied to actual project based on the structure of a solid steel frame.Then its response spectrum and history analysis are studied with SAP2000 software.Ultimately the seismic performance of frame structure installed new buckling-restrained brace is improved well by comparing with the analysis results of original frame structure and ordinary frame structure installed conventional braced.