Lateral-torsional buckling is a limit state that is often critical during the construction stages for steel buildings and bridges. The buckling capacity is increased by reducing the unbraced length of the members. Effective beam bracing can be achieved by providing either lateral or torsional bracing. This presentation focuses on the behavior of torsional bracing systems and the various factors that impact the behavior.
The results of a number of recently completed studies are covered as well as an overview of recent changes in design specifications. In addition to covering the fundamental torsional bracing behavior, some recent innovations in stability bracing for beams are also discussed.
Todd Helwig, Ph.D., P.E., has had a 29-year career teaching and conducting research in the field of structural engineering. He holds the Jewel McAlister Smith Professorship in Engineering at the University of Texas at Austin. His primary area of interest is the design and behavior of steel structures with an emphasis in full-scale testing, field monitoring, structural stability, fatigue, and stability bracing requirements.
He is a member of several technical committees within the American Institute of Steel Construction (AISC), the AISI/AASHTO T14 Steel Bridge Task Force and Design Advisory Group for Steel Bridges, the AASHTO/National Steel Bridge Alliance Collaboration Committees T11 (Design) and T13 (Analysis) and the Structural Stability Research Council (SSRC). He is a member of the AISC Committee on Specifications and is the past chair of SSRC.
He has developed and taught numerous short courses on the design and behavior of steel buildings and bridges on behalf of AISC, SSRC, and the National Highway Institute. More than 5000 engineers have attended his short courses in person with thousands more attending webinars.
His research has been recognized with several awards including the 2023 George Richardson Medal presented at the International Bridge Conference, 2022 Richard S. Fountain Award given by AISC/AASHTO/NSBA, the 2022 AISC Lifetime Achievement Award, the 2017 AISC T. R. Higgins Lectureship Award, the AISC Special Achievement Award, the ASCE Collingwood Research Prize, the ASCE Moisseiff Award, and the ASCE Shortridge Hardesty Award.