Buckling mechanism and global stability design method of buckling-restrained braces

Design formulae of buckling-restrained braces, considering the stiffening part of the core and the effect of friction, are proposed, based on theoretical analyses of the buckling mechanism of the steel core in the presence of a gap between the core and the restraining member. The theoretical analyses are validated by finite element analyses. Compared to existing methods, the results of the proposed analyses are generally better and show the closest correlation with the results of the finite element analysis.