LTB mode with tension-compression bracing 4

[Italo01]

Hello,

If i have two Beams with Tension-Compression bracing, what preventing them to buckling laterally to oposite sides. I see that the point of contact of the two bracing bars move for this failure mode, so a bolt connecting the two bars would be the only thing preventing this type of failure? If it is, how to determine if this bolt is adequate?

Thank you.

 

[Settingsun]

I feel that I can tell a theoretical story that fits those observations...

What you said is pretty much what the models show. I just wanted to do this analysis to compare the diagonal-only case with the full truss panel. Unfortunately, can't do the full truss panel with tension-only as I don't think Mastan handles T-only elements. I also ran top flange loading with three ideal torsional braces, and the ideal braces do the same job as lateral-torsional braces in this case.

I'm not sure how much difference there would be by doing a deeper beam if everything is kept in proportion. Maybe the K value (warping:St Venant ratio) would change in practice. My models had the beams spaced at 2*depth and 35:1 span/depth.