Experimental Study of Complex High-Strength Cold-Formed Cross-Shaped Steel Section
Publication: Journal of Structural Engineering
Volume 134, Issue 8
Abstract
This paper describes the design and experimental investigation of a series of compressive tests on a stiffened cross-shaped section fabricated from cold-formed high-strength steel of thickness and nominal yield stress of . The complex shape has been chosen so that it has a local buckling mode, two distinct distortional buckling modes, and a flexural-torsional mode. The first distortional buckling mode has a shorter buckle half wavelength and hence is classified as a short half-wavelength distortional buckling mode, while the other distortional mode has a much longer buckle half-wavelength and is classified as a long half-wavelength distortional buckling mode. The compression tests were carried out in a capacity SINTEC testing machine over a range of lengths with fixed-ended conditions. The varying lengths were chosen so as to observe the buckling modes and the possibility of interaction between them. The experimental results are then compared with design methods in the existing design standards. The methods include the direct strength method (DSM) recently incorporated in the North American specification and the Australian Cold-Formed Steel Structures Standard AS/NZS 4600. When compared to the existing methods, the test results indicate that at intermediate and longer specimen lengths, the interaction of local and distortional buckling modes has a significant effect on the strength of the section. This paper presents the procedures taken to design the complex shape and the experiments carried out to obtain the geometric imperfections and material properties of the specimens and the test results. New design methods are proposed for the local buckling DSM curve as well as for the distortional buckling strength curves so as to account for the effects of interaction of local and distortional buckling modes.
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Acknowledgments
This paper forms part of an ARC research project entitled “Interaction of local and distortional buckling modes in cold-formed high-strength steel” being carried out at the School of Civil Engineering at the University of Sydney. The writers would like to thank the Australian Research Council and the Centre of Advance Structural Engineering (CASE) of the University of Sydney for this financial support.
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Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 134 • Issue 8 • August 2008
Pages: 1322 - 1333
Copyright
© 2008 ASCE.
History
Received: Oct 18, 2006
Accepted: Nov 1, 2007
Published online: Aug 1, 2008
Published in print: Aug 2008
Notes
Note. Associate Editor: Benjamin W. Schafer
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