Tests of Profiled Steel Decks with Flat-Hat Stiffeners

The tests described in this paper are the second in a program carried out to determine the effectiveness of intermediate stiffeners in controlling the buckling modes of profiled steel decks. A series of specimens with “flat-hat” intermediate stiffeners were brake-pressed to designs that were chosen to ensure that the primary buckling mode took place in the elastic range and was not affected by plasticity. The specimens were loaded in pure bending, resulting in various buckling waveforms prior to ultimate failure through a plastic collapse mechanism. The experimentally determined buckling stresses are compared with studies performed using a computer analysis based on the finite-strip method. The existing design procedure for local buckling in Australian Standard AS1538-1988 and various methods involving distortional buckling are compared with the test results. A method of design accounting for the interaction of buckling modes and its effect on the ultimate moment capacity is proposed and compared with the...