The Seismic Performance Research Of Cross Section BRB And The Steel Frame

Framework-braced structure system have a lot of advantages in the application in seismic regions. Because its structure is simple, and it has strong lateral stiffness. Slanting braced can effectively reduce the horizontal displacement of the structure, and improve the internal force distribution of the structure. But under the reciprocating horizontal earthquake action, the braced is easy to appear lateral buckling. With the structure entering into elastic-plastic stage, the lateral stiffness of the structure and floor shear capacity drop sharply, and the interlayer displacement jump. The whole structure will be destroyed Buckling-Restrained Brace (BRB) is a kind of new energy dissipation component with high performance. It is improved on the basis of general brace. Under the effect of small earthquakes, it is the same as general brace. They can provide enough lateral stiffness to the structure. While under the strong earthquakes, BRBs can not only ensure structural lateral stiffness meeting the requirements, but also absorb energy of earthquake. They play a role to protect the safety of main frame structure.This article expounds the research background, structural principle, the adventages and disadvantages and research status of the BRB firstly. Also it analyzes the design method of stability in theory, and confirms the different part parameters. We can obtain the calculation formula of fatigue life of BRB from the article at the same time.Secondly, we analyze the cross section BRB component with ANSYS, a kind of general finite element software. Then we confirm that different part parameters such as constraint stiffness, clearance, connecting section stiffness and initial defects of the kernel unit have different influence to the performance of the BRB, and we get the reasonable value of each parameter.Last, the elastic-plastic comparative analysis among pure steel frame, the general brace frame and cross section BRB frame is studied with SAO2000, another finite element structure software. The analysis results show that:under the effect of small earthquakes, BRB plays the same pole as general brace in the framework, and they can effectively reduce the structural responses; but under strong earthquakes, the BRB begins to enter the yield stage and consume part of seismic energy through the deformation of the kernel unit. It can ensure the safety of main frame structure better.