Lateral Torsional Buckling Restraint of an Upset Wide Flange beam

[msquared48]

Anyone ever braced the top flange of a 21" deep wide flange with web stiffeners tied to wood joists? Force to develop is only 4 kips to develop at the 1/4 points using the 2% general rule and that seems doable. Only concern to me is the use of wood joists instead of steel members at the quarter points.

Mike McCann, PE, SE (WA)

 

[jayrod12]

Not in the direct scenario you are discussing, but I have counted wood joists framing into a steel beam as lateral bracing of the top flange. But they were connected to a nailer that was bolted to my steel beam.

provided you had a solid connection between the wood and the steel I can't see it being an issue.

 

[KootK]

I've done it. The trouble with wood as bracing is rarely the strength so much as the stiffness. A wood bracing member, and the wood diaphragm that holds it still, are usually a good deal less stiff than a comparable steel system normally is. As long as you check the bracing strength and stiffness using the AISC provisions, you should be fine.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.