Lateral Torsional Buckling of Wooden Beams with Midspan Lateral Bracing Offset from Section Midheight
Publication: Journal of Engineering Mechanics
Volume 143, Issue 11
Abstract
An energy-based solution is developed for the lateral torsional buckling analysis of wooden beams with a midspan lateral brace subjected to uniformly distributed loads or midspan point load. The predicted critical moments and mode shapes are shown to agree with results based on three-dimensional finite-element analysis. The study indicates that such beams are prone to two buckling patterns: a symmetric mode and an antisymmetric mode. Whether the symmetric or the antisymmetric mode governs the critical moment capacity is shown to depend on the bracing height. A technique is developed to determine the threshold bracing height required to maximize the critical moment. A parametric study is conducted to investigate the effect of lateral bracing and load height effects on the critical moments. Simple design equations are developed to predict critical moments for a practical range of cases. The limitations of the simplified procedure are discussed. For cases outside the scope of the simplified procedure, designers are recommended to adopt the more detailed energy-based solution. Design examples are provided to illustrate the merits and applicability of the proposed procedure in practical situations.
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Acknowledgments
The authors gratefully acknowledge funding from the Natural Sciences and Engineering Research Council (NSERC) of Canada to the second and third authors.
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Published In
Journal of Engineering Mechanics
Volume 143 • Issue 11 • November 2017
Copyright
©2017 American Society of Civil Engineers.
History
Received: Aug 10, 2016
Accepted: May 25, 2017
Published online: Sep 14, 2017
Published in print: Nov 1, 2017
Discussion open until: Feb 14, 2018
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