Seismic behavior of ConXL rigid connection in box-columns not filled with concrete

•The new connection in filed box-columns is ConXL moment connection.•ConXL connection makes a rigid diaphragm around the box column.•Seismic behavior of ConXL connection in box-column not filled with concrete is evaluated.•All specimens showed appropriate seismic behavior.•The column will remain without any remarkable local buckling to the end of loading.

Box-columns are suitable members for structures with moment frames in two directions but performing the internal continuity plate in them causes some practical troubles. Details of the new proposal to reduce this problem in box-columns is ConXL connection. The objectives of presenting these details are industrializing, removing weld in workplace, removing continuity plate, enhancing quality, speeding up the construction and simplifying the inspection. This connection is a set of collar flanges and collar corners. Through the distribution of force among these elements, forces are transmitted from beams to the columns. This paper is going to study the cyclic behavior of this type of such a connection numerically using ABAQUS. For this purpose, to verify the modeling, the numerical results of specimens; RBS, end plate, and bolted angle connection are compared to experimental results and a good agreement is observed between numerical and experimental data. Afterward eleven types of ConXL connections are studied including RBS and normal beams in box-columns not filled with concrete with axial force in single, planar and bi-axial loading conditions. Results showed that seismic behavior of all specimens is appropriate and that seismic behavior of this connection for typical beams is proper in the over 0.04 radian rotations. Also the column will remain without any remarkable local buckling.