Analytical estimates for the lateral thrust in bolted steel buckling-restrained braces

Analytical expressions are developed for the lateral thrust exerted by the core of a buckling-restrained brace (BRB), when, upon a prescribed axial loading history, it buckles, coming into contact with the external retaining structure. Account is taken of (i) the elastic stiffness of the containment case; (ii) the possible flattened shape of each buckled wave in the zones of contact with the containment profiles; and (iii) the increase in the lateral thrust due to loading-unloading in the presence of linear kinematic hardening. Comparisons with both experimental and numerical results confirm the effectiveness of the analytical predictions. The proposed calculation techniques for the lateral thrust might be of help in the design procedures of BRBs