An investigation of the effects of fastener spacing in built-up cold-formed steel compression members

This study is focused on built-up cold-formed steel compression members used as jamb studs to frame around door and window openings in axial load bearing stud walls. Typically the jamb stud is a box-shaped built-up member consisting of a track section overlapping a channel section.; In this study the interconnection between the channel section and track section is investigated. A total of 62 full-length built-up members were tested in compression. The specimens were 2500 mm in length with varying thickness, section depth and fastener spacing. Self-drilling sheet metal screws were used to connect the track section to the channel section. The track section was "cut short" at the top and bottom of the member and the members support conditions in the test frame were designed to represent the alignment tracks used in stud walls as is the standard framing practice in service. In addition to the full-length built-up compression member tests, 13 channel section and nine stub-column tests were conducted.* (Abstract shortened by UMI.); *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Microsoft Office.