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.

A State-of-the-Art Review of Passive Energy Dissipation Systems in Steel Braces

“…Eccentric Braced Frame (EBF) configuration is similar to the concentrically braced frames with the exception that at least one end of each brace must be connected eccentrically to the frame which leads to a small connecting link often known as a ductile link. This link provides the structure's essential ductility and energy dissipation [31][32][33][34][35][36][37]. The difference between the concentric and eccentric bracing systems, as seen in Figure 2, is the presence of transverse stiffeners in the link beam due to the shear force and the flexural moment within it due to earthquake forces.…”

Studi Numerik Kinerja Balok Baja Dengan Variasi Jarak Pengaku Menggunakan Program Msc. Patran/Nastran

“…Regangan baut sambungan link-to-beam paling tinggi, sedangkan regangan baut sambungan balok-kolom dan kolom-kebrresing lebih kecil. Sistem struktur ini menunjukkan kapasitas disipasi energi yang lebih tinggi dan manfaat ekonomi yang baik [17]. Pengaku diagonal badan dapat meningkatkan kinerja link panjang dalam hal : kekuatan kekakuan dan dissipasi energi dalam menahan beban lateral.…”

Behavior of a Multi-Story Steel Structure with Eccentric X-Brace

“…The previous studies primarily concentrated on eccentrically braced steel frames [28,29]. Popov [30,31] reviewed the current literature on EBFs and suggested various design modifications using the capacity design technique.…”