Nonlinear finite element analysis of CFT-to-bracing connections subjected to axial compressive forces

The Abaqus finite element program together with nonlinear material constitutive models for concrete-filled tube (CFT) and steel gusset plate is used to analyze the behaviors of the gusset plate type CFT-to-Bracing connections subjected to axial compressive forces. It is found that the failure of CFT-to-Bracing connections occurs below the connecting area. Local bulged shapes of the steel tube might take place in the areas close to the gusset plate and the fixed end under the failure stage. The ultimate strengths of the CFT columns slightly increase with the increasing of the load ratio and the thickness of the gusset plate. The introduction of the cutouts on the gusset plates slightly increases the ultimate strength of the CFT column and causes more local bulged shapes on the steel tubes below the connection area under the failure stage.