Research on the Hysteretic Behavior of Double-Square-Steel Tubular Buckling-Restrained Braces with Stainless Steel Energy Dissipation Plates

The double-square-steel tubular buckling-restrained brace is a novel type of buckling-restrained brace composed of welded energy dissipation plates，inner tubes， and outer tubes，which can effectively avoid weak damage at the ends of buckling-restrained braces. In order to explore the hysteretic behavior of buckling-restrained braces with stainless steel energy dissipation plates，the energy-dissipating behavior of the braces was studied through quasi-static loading tests and finite element analysis.The test results showed that this type of brace exhibited significant hysteretic behavior. Under axial loading，the brace mainly depended on the plates’ entering the plasticity stage to dissipate energy. During loading， the tubes remained elastic，but local buckling occurred on the surfaces of the outer tubes.Compared with braces of the same size made of carbon steel Q235B plates，this brace exhibited better strength. Four algorithms of different plate arrangements were designed in order to study the effect of plate arrangement on the hysteretic behavior of this type of brace using ABAQUS.The optimal plate arrangement was determined based on the study. A finite element parametric analysis was carried on the brace with the optimal plate arrangement，analyzing the effects of the middle and terminal widths of the dissipation section on the plates， as well as the plate thickness， on the hysteretic behavior of the brace.The FEM results showed that changing the middle width of the energy dissipation section on the plates had a greater effect on the strength， stiffness， and energy dissipation capacity of the braces， while changing the terminal width of the dissipation section and the plate thickness had a lesser effect on the braces.