An analysis of residential steel framed structures was carried out to determine the maximum actions (permanent, imposed and wind) applied to structural members. Steel-framed domestic structures are essentially very similar to traditional timber framed houses, except that thin-walled steel sections are used for the framing. The steel members are manufactured by a cold-rolling process which shapes steel roll into the sections required. An evaluation of several systems currently in use was required to gain an insight into the various issues related to such systems. The final aim of the project is to design a new steel-framed housing system to provide a low cost alternative for the builder. Calculation of the design actions in the various elements of domestic steel frames (such as wall frames, roof trusses, and floor joists) was required for the project of which this thesis is part. With the design actions calculated, it was possible to create building tables to allow construction with the new system. Another aspect of this project is the design of the new sections (such as wall stud sections). The proposed sections have been analysed by a thin wall computer modelling program called and the capacities calculated. As yet, only the stud building tables have been finalised. It is hoped that the remaining tables can be completed shortly so that manufacture of the cold rolling machine and testing of the member frames can be commenced.
In order to calculate the design actions on a typical domestic steel frame, it was first necessary to thoroughly study the appropriate Australian Standards. These were primarily AS/NZS 1170 (Structural Design Actions), AS 4055 (Wind Loads for Housing) and AS 3623 (Domestic Metal Framing). It was found that although builders still used AS 4055 (or the building tables derived from it), this code had several limitations such as the maximum span and roof pitch of the structure. AS/NZS 1170.2 Wind Actions did not have these limitations; however a corresponding system had to be developed to allow for the simplified wind classifications (W33, W41, etc) from AS 4055 to be used.