Web Yielding, Crippling, and Lateral Buckling under Post Loading
Publication: Journal of Structural Engineering
Volume 133, Issue 5
Abstract
Unstiffened, unbraced steel beams used in bridge falsework are subjected to patch loads from timber or steel posts. This paper investigates the critical web limit states in these types of beams experimentally and through finite-element analysis. Existing equations were appropriate for calculating the web yielding and crippling capacity, as observed in experiments, except that a 1:1 stress gradient through the flange and fillet of the web is found to be more appropriate and conservative for web yielding than the 2.5:1 gradient assumed in the current AISC specifications. Lateral deformation of a beam flange, due to buckling of the web, was also observed experimentally. The capacity of the web for resisting lateral buckling can be calculated assuming that the web of the beam acts like a column with an appropriate effective area and length factor. The effect of accidental eccentricity between the flange and post is not significant if limited to three times the web thickness. Blocking is approximately 50% effective in increasing the web yielding and crippling capacity. Bracing or stiffeners should be used to prevent lateral buckling of a web where necessary.
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Acknowledgments
The writers would like to extend their gratitude to the California Department for Transportation for funding of this study under Contract No. UNSPECIFIED59A0445, with special thanks to John Lammers and Peter Lee for their assistance and direction.
References
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Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 133 • Issue 5 • May 2007
Pages: 665 - 673
Copyright
© 2007 ASCE.
History
Received: Oct 18, 2005
Accepted: Jul 27, 2006
Published online: May 1, 2007
Published in print: May 2007
Notes
Note. Associate Editor: Donald W. White
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