Concrete Filled Tubular Bracing Subjected to Cyclic Loading

The energy absorption of concrete filled, hollow-steel bracing was analyzed respect to geometric and mechanical parameters including the width-to-thickness section ratio, slenderness level, and strength of the steel and concrete. Local buckling and ductility were also investigated with respect to variation in the cross-section. The infill increased the compression resistance, even after multiple, inelastic load reversals. This resulted in improved ductility capacity by limiting local buckling and in some cases preventing the local buckling. The energy absorption of such braces is appraised with respect to earthquake design presented in different international standards. The overall system effectiveness was assessed by comparing infilled bracing to an existing state-of-the-art, buckling restraint bracing system. The results showed the energy dissipation in buckling restraint bracing systems is more of in comparison with tubular bracing system designed by European and American codes in higher cycles.