Torsional Brace Strength Requirements for Steel I-Girder Systems
Publication: Journal of Structural Engineering
Volume 146, Issue 1
Abstract
Effective stability bracing of beams can be achieved by either preventing lateral movement of the compression flange or restraining twist of the beam cross section. Bracing that restrains twist is aptly referred to as torsional bracing. Adequate stability bracing must satisfy both stiffness and strength requirements. The torsional brace strength requirement in the latest edition of the AISC specification (2016) was significantly changed from the previous edition of the specification (2010). This paper presents a parametric study on the strength requirements of beam torsional bracing. An overview of the many factors affecting bracing behavior is provided. The paper demonstrates that the latest expression results in brace strength predictions that can be significantly nonconservative. The paper recommends a return to the strength provisions provided in previous editions of the specification.
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Acknowledgments
The authors would like to acknowledge the China Scholarship Council for the financial support (201706260122) of Yangqing Liu in allowing him to participate in this research effort at the University of Texas at Austin.
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Information & Authors
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Published In
Journal of Structural Engineering
Volume 146 • Issue 1 • January 2020
Copyright
©2019 American Society of Civil Engineers.
History
Received: Jan 24, 2019
Accepted: Jun 2, 2019
Published online: Nov 13, 2019
Published in print: Jan 1, 2020
Discussion open until: Apr 13, 2020
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