Seismic Behavior of Steel Braced Frames Equipped with Metal Foam

One of the methods for improving the seismic behavior of structures was to use inactive control devices. Recently, in civil engineering applications, a relatively new material named metal foam has been utilized progressively due to its high energy dissipation capability and remarkable axial strain. In this study, several non-linear time-history analyses were conducted for investigating the seismic behavior of steel frames equipped with the composite brace using a three-dimensional (3D) finite element (FE) method. Crushable foam (CF) and elastic-perfectly plastic models were considered for metal foam and steel members. FE results revealed that the maximum drift ratio decreased by 35% and 72% under near-field and far-field records in the steel frames equipped with composite brace compared to the conventional steel brace frames. Employing the composite brace led to prevent global buckling of the brace and consequently decrease in load-bearing capacity. Furthermore, composite brace caused the reduction of bending moment demand in the first-story column by 18%.