Experimental Evaluation of Square and Circular Concrete-Filled TubeBraces

The current investigation was experimentally undertaken to assess the performance of square andcircular Concrete−Filled Tube (CFT) braces widely used in Special Concentrically Braced Frames(SCBFs). To assess the seismic performance of CFT braces from initial elastic range to fracture, CFT bracesmust be considered in the system−level of multi−story SCBFs. However, the structural performance ofCFT braces in the system−level of multi−story SCBFs have been investigated in the limited studies. Thecurrent study was experimentally undertaken to evaluate the seismic performance of CFT braces withsquare and circular cross−section shapes from initial elastic range to fracture in the system−level ofmulti−story SCBFs. Two full−scale one−bay, two−story SCBFs with two various cross−sections, namelysquare−CFT, and circular−CFT, for braces and columns were considered and subjected to a cyclic lateralloading. Assessing CFT braces with various cross−sections indicated that the local buckling and crimpingin square−CFT braces were more severe than circular−CFT braces. In addition, it was found from theexperimental observations that the rupture propagated much more quickly in the circular−CFT braces thanthat in the square−CFT braces and consequently, the circular−CFT braces fractured immediately.

Experimental Evaluation of Square and Circular Concrete-Filled TubeBraces Keywords:

Square−CFT brace , Circular−CFT brace , Seismic performance , Two−story SCBFs.