Abstract
Maximum strength and plastic rotation capacity of square hollow section members made of SN-steel subjected to axial compression and bending are investigated. Square hollow sections include a)fabricated by welding four plates and b)hot finished. The equivalent width-to-thickness ratio of compression side flange of square hollow section members under combined compression and bending are assessed using experimental results. The prediction formulae on maximum strength and plastic rotation capacity are derived by combining the theoretical moment-rotation relationship and the maximum buckling strength of compression side flange defined by the equivalent width-to-thickness ratio. The prediction thus obtained are compared with experimental results to show the satisfactory correlation. The width-to-thickness ratio limitations according to ductility demand levels are suggested.
