Seismic Behavior of the Removable Links in Eccentrically Braced Frames with Semirigid Connections

Abstract

Eccentrically braced frames (EBFs) have good elastic stiffness, while semirigid joints can provide greater ductility and make all components easy to fabricate. With application of semirigid connections to EBFs, a seismic structure can be formed. After earthquake, damaged components can be easily replaced, and repair costs and maintenance time can be reduced. In order to study the seismic performance of this type of structure, four single-story plane specimens were tested under low-cycle cyclic loads. Also, a total of 7 EBF models were investigated through three-dimensional, nonlinear finite element analysis. Good agreement is achieved between the simulation and experimental results. The results show that the failure modes of the EBFs with semirigid connections are the fracture at link end plate connection, and no obvious buckling deformation and cracks occur in the other components. The EBFs with semirigid connections exhibit good inelastic rotation ability, and the inelastic rotation of all specimens and models exceeds the limit of 2016 AISC specification. Due to the slip between members, the hysteretic curves of those new structures show different degrees of pinching phenomenon and it becomes more obvious with the increase of the length of links. By analyzing the strain of the bolts, it is found that the bolt strains of the joints of link-to-beam are the highest, while the bolt strains of the joints of beam-to-column and column-to-brace are smaller. This structure system shows higher energy dissipation capacity and good economic benefits.