Study On Seismic Performance Of The Buckling-restrained Brace Steel Frame

Earthquake is the greatest impact on human production and life of natural disasters. In the earthquake prone areas, the building can meet the requirements of the earthquake, people’s lives and property safety. Ordinary central support can provide additional lateral rigidity to the structure, so it is widely used in the actual structure in the earthquake prone areas. But in recent years, the practical engineering shows that the general support in the cross section of the buckling, which makes the bearing capacity of the structure decreased, and then cause the structural damage or even collapse. In order to improve the buckling performance of the central support, a new type of structure system, which is a new type of structure system, is presented. Buckling restrained brace(BRB) in Europe and the United States as well as Japan has been produced and applied to practical engineering and Show good seismic performance.In this paper, a simple theoretical analysis of the BRB component is given, and the support floor, and the bearing capacity of the support are determined. In determining the constitutive relation of BRB, the original use of the support deformation as the ultimate strain of the member is determined by the corresponding supporting deformation when the floor is reached.In the establishment of finite element model, the concept of "anti side stiffness ratio" is introduced into the design of the component. In the design of BRB, we first determined the floor of the existing project, and then through the "anti side stiffness ratio" to determine the "optimal" stiffness of the BRB support, and then determine the supporting section of the design method.The vibration mode decomposition response spectrum method and elastic plastic time history analysis are compared with three kinds of models, which are ordinary steel frame, ordinary central bracing frame and anti buckling support frame. In the elastic stage, the seismic response of the two support frames are reduced, but the gap between the two is small.