Development of detachable replaceable links for eccentrically braced frames

Abstract

Summary Eccentrically braced frames (EBFs) can be repaired after a major earthquake by replacing the links. The link replacement is not a straightforward process and is influenced by the type of the link and the amount of residual frame deformations. The past decade has witnessed the development of different types of replaceable links such as end‐plated links, web connected links, bolted flange and web spliced links, and collector beam and brace spliced links. All of the developed replaceable link details, except the web connected links, are not suitable for link replacement under residual frame drift. In this paper, a detachable replaceable link detail which is based on splicing the link at its mid‐length is proposed. The detail is well suited for installation under residual frame drifts. In addition, the weight and size of the members to be transported and erected are reduced significantly, thereby facilitating the replacement procedure. Performance of this proposed replaceable link is studied by conducting six nearly full scale EBF tests under quasi‐static cyclic loading. The link length ratio, type of end‐plated mid‐splice connection, and the amount of residual drift are considered as test variables. The test results revealed that the inelastic rotation capacity of the detachable replaceable links exceeds the requirements of the AISC Seismic Provisions for Structural Steel Buildings. No failures are observed in the end‐plated mid‐splice connections demonstrating the potential of the proposed details. The detachable replaceable links are investigated by numerical analysis as well to further validate their applicability and to develop design recommendations.

The Effects of Steel Core Imperfection, Gap Size and Friction Coefficient on the Behavior of All-Steel Buckling Restrained Braces

“…Monotonic loading was preferred for numerical analyses in order to reduce computational cost and convergence problems. With accurate numerical modeling of the material, the results of monotonic numerical modeling can be compared with the results of experimental cyclic loading [28][29][30][31][32][33]. Therefore, a stabilized material model described in Bozkurt et al [29] and Özkılıç et al [28] was utilized herein.…”

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

“…rough analysis, the major factors affecting the performance of the two kinds of links are obtained. Many experimental tests were performed in the past on removable links [16][17][18][19][20][21][22][23][24][25][26]. For instance, Chesoan et al [16] carried out experimental research on full-scale dual eccentrically braced structure.…”

“…e links exhibited a very good ductile behavior, developing stable and repeatable yielding. Bozkurt et al [26] proposed a detachable replaceable link detail, which is based on splicing the link at its mid-length. Performance of this proposed replaceable link is studied by conducting six nearly full-scale EBF tests under quasi-static cyclic loading.…”

Nonsymmetrical loading protocols for shear links in eccentrically braced frames

“…A finite element (FE) analysis of the specimens was conducted to observe the behavior at link rotation angles beyond the maximum value observed in the experiments. For this purpose, the modeling details explained by Bozkurt et al were adopted. An isolated link was analyzed under monotonic loading using the stabilized cyclic stress‐strain curve.…”

“…In the experiments, the link is connected to the floor beam and braces, while in the FE model, idealized boundary conditions were used. A more detailed discussion of the effects of boundary conditions can be found in Bozkurt et al The link shear resistance increases from 365 to 488 kN resulting in a change of 33% as the link rotation angle increases from 0.09 to 0.24 rad. More importantly is the level of axial force developed in the link.…”