Finite element analysis of concrete filled tube column to flat plate slab joint

• New connection detail of the CFT column-flat plate slab was proposed.
• Design equation of the connection is proposed through finite element analyses.
• Strength is proportional to column thickness, to plate length and thickness.
• It is inversely proportional to the edge distance.
• Difference between proposed design eq. and FEM analysis values is less than 10%.

For high-rise buildings, the storey height is an important factor influencing the economic efficiency of buildings. The structural system consisting of concrete filled tube columns and flat plate slabs is relatively new. However, the structural behavior of the connection between the concrete filled tube column and the flat plate slab has not yet been fully explored. The finite element analysis is therefore used to examine the stress concentration, load flow, and excessive deformation acting on the connection. Three types of connection details were compared. The analytical parameters are width, thickness of steel tube, length, thickness of wing plate, strength of steel, and eccentricity of rebar. 84 models were analyzed to find the appropriate design equation of the final connection detail. The corresponding proposed design equation showed a good agreement with the finite element analysis results.