Warping Equations for U-Shape

[EngDM]

Does anyone have readily available equations for warping and torsional constants for a U-Shape? Would I be okay to use the C-Shape equations? I'm analyzing cold formed U-members for a joist web, and the supplier does not provide these values but I need them to find Feyz as specified in S16 Clause 13.3.2.

 

[canwesteng]

This is the best I have

 

[GregLocock]

And here's a very dull paper. I imagine it can be extended to a U by a nasty approximation or two https://www.kssc.or.kr/wonmun/KSSC_3_2007_7_4_297(C).pdf

 

[KootK]

Unless I was going to be doing a whole lot of this, I would just treat the shape as though it were only the two opposing sides acting in strong axis flexure independently. That's where all of the torsional stiffness will be anyhow.

 

[EngDM]

I'm just trying to calculate web compressive strength of Canam Joists. I have a paper from them with most properties except for warping and torsion. I don't think these failure modes would govern a joist anyways considering the ends are sandwiched between the top chords, but best to check

 

[KootK]

Yeah, with short lengths and rotational restraint at each end, it won't take much to prove that torsional buckling won't govern. Probably why the torsion parameters aren't tabulated. With that in mind, I like my poor boy approach even better.