Design of through beam connection detail for circular composite columns

Steel pipes with relatively thin wall thicknesses and filled with high strength concrete have been used in building construction. This structural system allows the designer to maintain managable column sizes while obtaining increased stiffness and ductility for wind and seismic loads. Column shapes can take the form of tubes or pipes as required by architectural restrictions. Additionally, shop fabrication of steel shapes helps to ensure quality control. In this type of construction, in general, heavy steel beams are framed to the composite columns at each floor level. Often, these connections are required to develop the shear yield and plastic moment capacity of the beam simultaneously. In a previous investigation, a new connection detail for composite columns consisting of a square tube filled with high-strength concrete was developed. Knowledge gained from that investigation together with major revisions to general design philosophy and some simplifying assumptions are used to suggest a design procedure for a connection detail that could be used to connect steel beams to circular composite columns.