A practical and unified global stability design method of buckling-restrained braces: Discussion on pinned connections

• A practical global stability design method of pin-connected BRBs is proposed.
• Parametric study shows that the proposed method has an acceptable accuracy.
• A new method is proposed to unify global stability design of pin-connected BRBs.
• Several future research needs for the unified design method are presented.

The end bending moment induced by brace end rotation was recently found to have a negative effect on the global stability of buckling-restrained braces (BRBs). The proposed bending moment functions for the BRBs with traditional pinned connections, however, were found to be too complicated from practical view. Also, the relationship between the flexural behavior of BRBs and the brace end details has not yet been well understood, possibly resulting in misevaluation of BRB global stability capacity in design. In this paper, a moment amplification factor (MAF) method is proposed to simplify the bending moment function of the BRBs with traditional pinned connections, followed by parametric study on the key parameters affecting the MAF and presentation of the proposed simplified function. A unified global stability design method is proposed and implemented to the BRBs with pin-ended connections. Several future research needs for BRB global stability are presented finally.