A new Coplanar Dual Core Buckling-Restrained Brace

Abstract

This study presents a new all-steel Buckling-Restrained Brace (BRB) named Coplanar Dual Core (CDC) BRB, that consists of a rectangular cross-sectional core divided into two coplanar yielding lateral bands, whose movements are constrained by an external restrainer (ER) and by an internal restrainer (IR). In contrast with the traditional BRB with dog-bone shaped core, the CDC-BRB has the advantage that the core can be easily extracted and inspected. The ER is composed of two rectangular tubes welded to a pair of rectangular solid calibrated bars. The core and IR are simultaneously laser cut from the same sheet of steel, which provides additional advantages: minimum material waste, minimum laser cut length, regular and well controlled gap, reduction of weight and manufacturing cost. Formulae to design the CDC-BRB, to determine the appropriate values of the gaps, and to predict its response and ultimate energy dissipation capacity are proposed. Four specimens representing the new CDC-BRBs with different gaps are tested under cyclic loadings to failure. The results of the tests show that the cyclic behavior of the new CDC-BRB is stable, highly dissipative, and its response and ultimate energy dissipation capacity can be well predicted insofar the gaps fit the proposed values.