Numerical and experimental investigations on inelastic cyclic performance of mid‐span gusset plate connections

Abstract

Summary The design and detailing of gusset plate connections greatly influence the seismic performance of a special concentrically braced frame (SCBF). Recently, a balanced design approach has been proposed in order to develop significant inelastic deformation from multiple yield mechanisms and to delay the failure of connections of SCBF system. Although extensive studies have been conducted on the corner gusset plate connections of SCBFs, research on the detailing of mid‐span beam gusset plates is rather limited. This study aims at investigating the required free length for the detailing of the mid‐span gusset plates with different brace slenderness ratios. A nonlinear finite element analysis has been conducted for a braced frame with 4 different values of linear clearance in the mid‐span gusset plates and 2 values of brace slenderness ratios. In all simulation models, the corner gusset plates have been designed using balanced design approach and detailed using an elliptical clearance of 8 times the gusset plate thickness. An experimental study has also been conducted on 2 gusset plate sub‐assemblages having similar brace slenderness ratio but with 2 different values of linear clearance in the middle gusset plates. The lateral drift capacity corresponding to the brace fracture and the level of damage are found to be dependent on the detailing of the gusset plates. Based on the results of numerical and experimental studies, the required free length has been recommended for the detailing of middle gusset plates of SCBFs of different brace slenderness ratios.

Seismic Behavior of Concrete Columns Retrofitted with a Brace-Type Replaceable Steel Link

“…The efficacy of braces in dissipating the input of seismic energy largely depends on the design and detailing of the gusset plates connecting the braces with the beams and columns. The brace stress is transferred to the concrete frames by the gusset plates connecting the existing structures and the braces [ 3 , 4 ]. Particularly with double K-braced frames, significant stresses and deformations may occur since two braces are joined to one gusset plate, and complicated analysis and design are needed.…”