| In this paper，two new kinds of all-metallic buckling-restrained brace were studied,which were Triple Steel Square Tube Buckling-Restrained Brace (TSST-BRB) and New PlateBuckling-Restrained Brace (NP-BRB). By summing up the methods from domestic andforeign data related to buckling restrained braces, we used ABAQUS finite element softwareto research the TSST-BRB and NP-BRB hysteretic behavior and bearing capacity. Accordingto results of finite element method analysis, the corresponding experimental specimens weredesigned. The hysteresis behavior was verified by the finite element modeling analysis andexperimental research results and the restoring force model of the two all-metallic buckling-restrained braces were extracted. By using ETABS and Seismostrut to a10stories ofreinforced concrete frame structure building located at8degree (0.30g) seismic area whichcouldn’t not meet the inter-story drift limi, normal braces and TSST-BRBs were put into thereinforced concrete frame structure coming to being moment restrained brace frame (MRBF)and buckling-restrained brace (BRBF). The comparison of the seismic response analysisresults between MRBF and BRBF were given and the designing of TSST-BRB and NP-BRBwere summarized at last, especially the designing examples of them.ABAQUS finite element software was used to study the influence that TSST-BRB coresteel with different width-thickness ratio could result in. Subsequently,25sets of TSST-BRBwith different conditions were designed to study the parameters for hysteretic behavior andbearing capacity. Which including different kinds of notch, numbers of notch, depth of notch,restrained ratio and gaps. The results indicated that the hysteretic curve of the TSST-BRB wasfull and symmetrical, and the TSST-BRB had excellent hysteretic energy dissipationperformance. TSST-BRB with annular notch,2~3numbers of notch,13.3%~20%length ofnotch, and10%~20%depth of notch had the best behavior.5experimental specimens ofTSST-BRB were designed and tested. Through low cyclic loading testing to verify hysteresisbehavior of the two new all-metallic buckling-restrained brace and compare the differenceshysteretic behavior between core stress unit which are weaken and not, and compared withthe finite element results. The testing results coincided well with the FEM analysis results.TSST-BRB could achieve yielding at the fixed aera. Finally, restoring force model wereextracted from the testing results. The restoring force mode model of TSST-BRB could besimplified as a bilinear model.As for the study of NP-BRB, theoretical analysis was used to dedused the axial stiffness of the core stress plate, the wavelength of multiple waves buckling, the overall stability andthe local stability conditions. On this foundation,14sets of NP-BRB with different workingcondition were designed and ABAQUS was also used to study the hysteretic energydissipation properties, bearing capacity, stress distribution characteristics and the core forceplate axial deformation and lateral deformation of constrained plates effects when the coresteel of plate with holes. The results indicated that the hysteretic curve of NP-BRB was fulland symmetrical and the energy dissipation behaviors were excelent. Using the result oftheoretical analysis, the designed NP-BRB coule meet the global and local stabilityrequirements. The NP-BRB had good behavior if the core steel plate transversal sectionweakened less than10%, the longitudinal section weakened in40%~60%.7experimentalspecimens of NP-BRB were designed and tested. Through low cyclic loading testing to verifyhysteresis behavior of NP-BRB and compare the differences hysteretic behavior between corestress unit which are weaken and not, and compared with the finite element results. Thetesting results coincided well with the FEM analysis results. NP-BRB could achieve yieldingat the fixed aera. Finally, restoring force model were extracted from the testing results. Therestoring force mode model of NP-BRB could also be simplified as a bilinear model.Based on seismic response analysis of TSST-BRBF, it was found that the energydissipation brace played a good energy dissipation behavior. TSST-BRBs were used asordinary braces under frequent earthquake while TSST-BRBs were used as energy dissipationdampers under rare earthquake. TSST-BRB could dissipate most of the energy that inputed tostructure. Finally, through the theoretical analysis and the experimental results, the designedmethods of the two new all-metallic of buckling-restrained brace were are studied and thedesigning examples were presented respectively. |
