Effect of Through Plate Connection on Transferring Loads in CFT Columns

Connection between an I-shaped beam and a CFT column has a prominent role in transferring gravity and seismic loads of the beam to the column; consequently, details of the connection shall mobilize the capacity of the concrete core and the steel tube simultaneously. In the proposed connection, beams on the forth sides of the column, are connected to the through plate assemblage which passes through the CFT column. Load transfer from the through plate to the column will take place through the weld between the connection plate and the steel tube, and also the bearing action and the friction force between the through plate and the concrete core. The proposed connection may promote confinement of concrete core in the region of connection in CFT columns as well, so the concrete section can mobilize to bear the load properly. This specification improves the seismic behavior of the connection, and it can be effective in seismic areas. The through plate connection has some advantages than other usual connections such as the mobilization of concrete by the friction force, load bearing and the lateral confinement in comparison to the steel beam which is only connected to the steel tube, and continuous place for casting concrete in the through plate connection which is more effective than the continuous through beam connection, because it can inhibit constructional problems, thus the quality of concrete mix might be improved in the connection zone. The behavior of this case under gravity and seismic loads is studied by the Finite element method.