Finite Element Analysis Of Buckling Restrained Brace With Ductile Casting Connectors

Bare frame structure and steel frame brace structure are widely used in the high-rise steel structure. While the lateral stiffness of bare frame structure is low, causing the excessive lateral under major earthquake. The lateral stiffness of steel frame-brace structure is high, however the braces will become buckling under major earthquake. Scholars devoted to the research of special center support steel frame (SCBF), which mainly consists of the hollow structural section (HSS) and the gusset plate. However, the results of the current study show that the design methods barrier the role of the brace owing to the tearing of severe weld, buckling of gusset plate, fracture of brace net section and inelastic shortening due to post-buckling behavior of brace, etc.The inelastic deformation performance of the supporting system is controlled by the buckling, post buckling and yielding of the steel. Therefore, in order to ensure the supporting system of large inelastic deformation without permanent brittle cracking and low cycle fatigue damage. On the one hand, large deformation is allowed by the design methods for the steel castings, which are used to act as a fuse. The steel castings can significantly improve the performance of the structure with proper configuration. The author has designed the supporting system with the ductile casting connectors, which can not only achieve the goal that the structure inelastic deformation occurs in the ductile casting area, but also improve the structure of low cycle fatigue life. On the other hand, the HSS replaced by the BRBs can play an important role in the structure. Known as that the BRBs are not easy to buckle, which can slow down the problems of buckling and post-buckling caused by the HSS. Thus, it can guarantee inelastic deformation of the supporting system.In this paper, in order to obtain the ductility, bearing capacity, failure mode, stress distribution under axial load and dissipation capacity, failure mode, stress distribution on key area under cyclic loading, different parameters of the buckling restrained braces with ductile casting connectors were studied by using ABAQUS finite element analysis software. The results obtained are as following:1) A new kind of buckling restrained brace with ductile casting connectors is proposed. It has many advantages such as light weight, convenient connection, high strength and stiffness at the connection segment.2) The ductility, bearing capacity, and the dissipation capacity of buckling restrained brace with ductile casting connectors are good.3) Under cyclic loading, the plastic deformation is only concentrated on the reduced part of ductile casting connectors, and the stress value on other parts of ductile casting connectors is small. This means that the aim of focusing the plastic deformation on the reduced part of casting connectors, dissipating energy by the casting connectors to protect structure can be realized by using the ductile casting connectors.