Performance Study Of New Plate Buckling-restrained Brace

In this paper, two kinds of all-steel plate buckling-restrained brace (BRB) were putforward in order to solve the problem of end damage and difficult to get the big bearingcapacity etc. of ordinary plate BRB, respectively named the perforating platebuckling-restrained brace (PPBRB) and the double plate buckling-restrained brace (DPBRB).The hysteretic energy dissipation performance of PPBRB and DPBRB were studied using themethods of experimental study and numerical simulation analysis. The seismic performanceof a concrete frame with PPBRB has been studied. And the preliminary design methods oftwo kinds of buckling-restrained brace were summarized, then the design examples weregiven. The main research contents of this article were summarized as follows:⑴For the problems of easy to be damaged at the end, the yield positions were notdetermined etc., PPBRB were put fordwarded based on the design concept “weaken to thecore unit is equivalent to the strength of other parts”. The core unit of PPBRB was perforated,the end of the brace use the embedded and strengthening structure, so the connection segmentcould be covered by the constrained unit. The PPBRB have the advantages of:①theopen-hole section of core unit can get the fixed point yielding and multi points yielding underaxial load;②the end of the brace was relatively strengthened after the core unit wasperforated, thus the strengthen measure of end could be simplified;③the end structure couldget big bending stiffness with small section, thus could to protect the end better;④the axialstiffness of the brace could be changed through the way of change the perforating size of coreunit;⑤the material of brace can be easily got and the brace could be easily made, what ismore the brace could be installed in the filler wall. Four test specimens of PPBRBs weremanufactured to do the quasi-static cyclic test, the hysteretic energy dissipation capacity andaccumulative plastic deformation of PPBRB were studied. The test results showed that thestructure of PPBRB is rational, the hysteretic energy dissipation capacity and accumulativeplastic deformation capacity are both well, and the mechanical model of PPBRB could besimplified as the double linear model. ⑵The numerical simulation analysis of PPBRB was carried out using the softwareABAQUS, then the results of numerical simulation analysis and experimental study werecompared to research the feasibility of using numerical simulation method to study theworking performance of PPBRB. The study results showed that: the hysteretic curves gotthrough numerical simulation matched well with the test results, they are both regular andsymmetrical; the performance ratios of PPBRB got through simulation has only a littledifference with the test result, showed that using the numerical method to study the workingperformance of PPBRB is feasible; and using the double linear model to research theperformance of PPBRB is feasible and secure.⑶In order to solve the problem of complex connection and large sickness under bigbearing capacity of ordinary plate buckling-restrained brace, a kind of new plate BRB calledDPBRB was put forward, of which the core unit was made of two steel plate which were putin two constraint tubes. The performances of DPBRB under different core plate sickness andlength were studied using the software ABAQUS, and the axial stiffness and bending wavelength were calculated. The research results showed that: the hysteretic curves of DPBRB wasfull and symmetrical, the performance ratios of DPBRB have no difference with the signalplate BRB which has the same cross section with DPBRB, indicate that the structure ofDPBRB is feasible;⑷Besed on the seimic performance analysis of PPBRB-BRBF, the good energydissipation capacity of PPBRB has been proved. Afeter the BRB was installed to the structure,the lateral stiffness of the structure has been increased under frequent earthquake, and undersevere earthquake, most of the energy has been dissipatied by BRB, thus the main structurewas well protected.⑸The design methods of new plate buckling-restrained brace were summarized,including the design and check method of core unit, constraint tube and connection segment.The points need to be noticed along the process of manufacturing the brace were concluded,and design examples of the brace were given, thus to provide certain reference of the designand application of new plate buckling-restrained brace.