Net Section Tension Capacity of Cold-Reduced Sheet Steel Channel Braces Bolted at the Web
Publication: Journal of Structural Engineering
Volume 139, Issue 5
Abstract
This paper examines the accuracy of equations specified by the North American and Australasian steel structures codes for determining the net section tension capacity of a channel brace. It points out that there are three distinct factors affecting the net section efficiency of a cold-formed steel channel brace bolted at the web. These factors include (1) the in-plane shear lag associated with stress concentration around a bolt hole that is also present in flat sheets, (2) the out-of-plane shear lag that is also present in an I-section bolted at the flanges only, and (3) the bending moment arising from the connection eccentricity with respect to the neutral axis. Each of the relevant factors is explicitly incorporated into the equation proposed in this paper for determining the net section tension capacity of a cold-formed steel channel brace bolted at the web. The proposed equation is demonstrated through laboratory tests on low-ductility channel braces having practical aspect ratios that were bolted onto flexible plates, to be more reliable than the code equations and those existing in the literature.
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Acknowledgments
The authors thank John Kralic, Manager, Lysaght Research and Technology, Bluescope Steel Limited, for supplying the G450 sheet steel materials used in this work. The authors thank Gregory Hancock, Emeritus Professor, University of Sydney, for his expert input concerning the state-of-the-art of bolted connection design in cold-formed sheet steel. The authors also thank Chris Cook, Dean of Engineering, and Muhammad Hadi, Head of the Advanced Structural Engineering and Construction Materials Group, both from the University of Wollongong, for supporting the laboratory tests that were conducted in the High Bay Laboratory of the Faculty of Engineering. The specimens were fabricated by Ritchie McLean and tested with the assistance of Jack Atkinson, an honors thesis student at the University of Wollongong.
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Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 139 • Issue 5 • May 2013
Pages: 740 - 747
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Aug 4, 2011
Accepted: May 16, 2012
Published online: May 18, 2012
Published in print: May 1, 2013
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