Low-cycle fatigue testing of extruded aluminium alloy buckling-restrained braces

Aluminium alloys have recently been employed to manufacture buckling-restrained braces (BRBs) with the aim of improving BRB durability in corrosive environments. Based on the ease with which aluminium alloys are extruded, the extruded aluminium alloy BRB is proposed to avoid the welded and relatively complex BRB end used in previous BRB research. This experiment, including 10 nearly identical specimens with or without stoppers, was performed to address low-cycle fatigue performance. According to the test results, the extruded BRB possessed a stable and repeated hysteretic performance, and the fracture location was random in the yielding portion of the brace. The failure of the extruded BRB was regarded as a brittle fracture compared to the typical failure of a steel BRB. The comparison between specimens with and without stoppers showed that the stoppers had no clear influence on the cumulative inelastic deformation, provided that the BRB was horizontally placed and the strain amplitude was lower than 2%. The low-cycle fatigue damage evaluation formula for the extruded BRB is recommended as a reference for strain-based damage assessment.

► Aluminium alloy BRB is developed to improve durability in corrosive environments.
► Extruded aluminium alloy BRB is proposed to avoid the welding of stoppers and ribs.
► Fracture location of extruded BRB was random in yielding portion of brace.
► Failure of extruded BRB was regarded as a brittle fracture compared to steel BRB.
► Stoppers have no clear influence on fatigue performance in this experiment.