Research On Mechanical Performance Of Structure With Buckling Restrained Braces

Framework supporting system has been one of the structure of high-level structure commonly used, but the traditional support prone to buckling instability, in order to ensure the overall stability of the support, can only increase the cross section size on the design, control the slenderness ratio. And support too often leads to the main structure members(beam, column) is relatively weak, when confronted with severe earthquake, for the main structure of the earthquake is very bad. Along with the development of the energy dissipation damping technology, the emergence of buckling constraint support solved this difficult problem, buckling constraint support support can be ensured only the yield without buckling instability, and can guarantee support ahead of the main structure into the yield condition, after its yield good hysteretic performance, consume most of the earthquake input energy, which can greatly reduce the damage rate of the main body structure subjected to severe earthquake.In this paper, on the basis of the theoretical derivation, using ANSYS finite element software support model of buckling constraints eigenvalue buckling analysis and modal analysis, and comparison with euler theory to confirm the accuracy of the models. On the basis of modal analysis, under the condition of considering the initial defects of four series of ultimate bearing capacity of the buckling constraint support analysis, factors affecting the buckling constraints, the bearing capacity of support has carried on the comprehensive research, and get the reasonable value range: restraint stiffness ratio of 2.0 ~ 3.0, core material generous than 5 ~ 15, constraints, 1 ~ 2 mm gap, the initial defects within 5/1000. Finally using the structural analysis software SAP2000 to buckling constraint supported steel frame structure with ordinary steel frame structure of a project example to carry on the dynamic time history analysis, the analysis shows that under the effect of more severe earthquake, the buckling constraint support steel frame similar to a normal support steel frame, in normal use and small earthquakes buckling constraint is supported with ordinary little difference; Under severe earthquake, buckling constraint supported steel frame of all the indexes than ordinary steel frame and good show in a large earthquake, the buckling constraints to support the first into submission, dissipation of seismic energy, reduce the dynamic response of the main structure under seismic action and up to the very good damping energy dissipation effect.The paper deeply analyses the force performance and influencing factors of buckling constraint support, as well as the buckling constraints supported steel frame structure with ordinary steel frame structure is analyzed, the research work and conclusions have important reference value for guiding the engineering practice, in order to further study the buckling constraint seismic performance of the support structure laid a good foundation.