Stiffness Requirements for Diaphragm Bracing of Beams
Publication: Journal of Structural Engineering
Volume 125, Issue 11
Abstract
Light gauge metal sheeting is commonly used in the building and bridge industry for concrete formwork. The metal forms, if properly attached to the beam or girder, often behave like a shear diaphragm and restrain the lateral displacement of the top flange, therefore improving the lateral-torsional buckling capacity prior to placement and hardening of the concrete. This paper presents the results of a computational study on the stiffness requirements for shear diaphragms used for beam bracing. Doubly and singly symmetric cross sections were studied. The parameters that were investigated included diaphragm stiffness, load type, load position, cross-sectional shape, and web slenderness. The type of loading has a significant effect on the bracing behavior of the shear diaphragm. Current solutions in the literature are based upon uniform moment solutions and often overestimate the capacity of diaphragm-braced beams. Solutions are presented that can be used to determine diaphragm stiffness requirements to prevent lateral-torsional buckling for general load applications.
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References
1.
ANSYS, finite element program users manual, version 5.0. (1996). ANSYS, Inc., Houston, Pa.
2.
Currah, R. M. ( 1993). “Shear strength and shear stiffness of permanent steel bridge deck forms,” MS thesis, University of Texas at Austin, Austin, Tex.
3.
Errera, S., and Apparao, T. (1976). “Design of I-shaped beams with diaphragm bracing.”J. Struct. Div., ASCE, 102(4), 769–781.
4.
Galambos, T. V., ed. (1998). Guide to stability design criteria for metal structures, 5th Ed., Wiley, New York.
5.
Helwig, T. A. ( 1994). “Lateral bracing of bridge girders by metal deck forms,” PhD dissertation, University of Texas at Austin, Austin, Tex.
6.
Helwig, T. A., Frank, K. H., and Yura, J. A. (1997). “Lateral-torsional buckling of singly-symmetric I-beams.”J. Struct. Engrg., ASCE, 123(9), 1172–1179.
7.
Lawson, R., and Nethercot, D. (1985). “Lateral stability of I-beams restrained by profiled sheeting.” The Struct. Engr., London, 63B(1), 3–13.
8.
“Load and resistance factor design specification for highway bridges.” (1994). 1st Ed., American Association of State Highway and Transportation Officials, Washington, D.C.
9.
Luttrell, L., ed. (1987). Steel Deck Institute design manual, 2nd ed., Steel Deck Institute, Canton, Ohio.
10.
Nethercot, D., and Trahair, N. (1975). “Design of diaphragm-braced I-beams.”J. Struct. Div., ASCE, 101(10), 2045–2061.
11.
Soderberg, E. ( 1994). “Strength and stiffness of stay-in-place metal deck form systems,” MS thesis, University of Texas at Austin, Austin, Tex.
12.
Specification for structural steel buildings—load and resistance factor design. (1994). 2nd Ed., American Institute of Steel Construction, Chicago.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 125 • Issue 11 • November 1999
Pages: 1249 - 1256
History
Received: Jan 14, 1999
Published online: Nov 1, 1999
Published in print: Nov 1999
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