Out-of-Plane Stiffness and Yield Strength of Cruciform Connection for Buckling-Restrained Brace

Abstract

In order to prevent out-of-plane buckling of buckling-restrained brace, its connections must have enough out-ofplane stiffness and be kept elastic. This paper deals with out-of-plane stiffness and yield strength of bucklingrestrained brace's connection whose section is cruciform. Firstly, methods of calculating both out-of-plane stiffness and yield strength of connection are proposed by means of RBSM. And secondly, experimental verifications to load connection specimens were conducted. As a result, it is clarified that out-of-plane stiffness is very small if finstiffener is not connected to beam-flange. Therefore, it is recommended that fin-stiffener should be welded to beamflange to satisfy required out-of-plane stiffness and yield strength.

Local buckling restraint condition for core plates in buckling restrained braces

“…In [1], the condition of core plate local buckling [item (c)] was studied by using an elastic spring for the in-filled mortar, and it was concluded that there is only a small risk for local buckling failure in typical BRBs. The effect of the BRB connection stiffness [item (d)] was researched by Takeuchi et al [10], Tsai et al [11], and Kinoshita et al [12], and the effective buckling load considering the stiffness of the connections of BRBs was researched by Tembata et al [13] and Kinoshita et al [14] [item (e)]. For the conditions in item (c), however, it has been reported that there are risks of local buckling failure where the wall thickness of the restrainer is relatively small compared to the cross-sectional area of the core plate [15].…”

Out‐of‐plane stability assessment of buckling‐restrained braces including connections with chevron configuration

“…Comparing Equations (21), (22), and (23), the minimum N cr r is determined by the asymmetrical or one-sided mode. As a result, the stability limit-determined by the cross point of Equations (4) and (20)-can be expressed as Equation (1).…”

“…gusset plate deformation, the torsional stiffness of the main beam, the torsional stiffness given by rigidly connected secondary beams perpendicular to the main beam, the bending stiffness of the other BRB in tension, and the bending deformation of the main beam section along a weak axis. For practical design, an easy evaluation method for calculation of the gusset plate stiffness, K' Rg , is proposed in Reference [22]. Also, an evaluation method for calculation of torsional stiffness of the main beam is proposed as follows in Reference [23], whose validity is confirmed by FEM analyses.…”

“…C 1 and C 2 in Equation (24) are defined in Equation (22). Furthermore, the stability limit with plastic hinges at the gusset plates, N lim2 , can be expressed as follows:…”

Out-of-Plane Stability of Buckling-Restrained Braces Placed in Chevron Arrangement

“…Tembata et al (2004), 24 Kinoshita et al (2007), and Takeuchi et al (2009) derived a comprehensive set of analytical 25 solutions to the out-of-plane stability problem of BRBs, and validated the solutions with static, 26 cyclic loading tests. Takeuchi et al (2004; and Kinoshita et al (2008) investigated the 27 rotational stiffness of BRBs and its bracing connections, respectively, acknowledging these 28 stiffness values to be key factors that control the out-of-plane stability of BRBs. Koetaka and 29 Kinoshita (2009) provide a review of the Japanese literature and propose general design criteria 30 to control out-of-plane buckling of BRBs placed in a chevron or single-diagonal arrangement.…”