Warping Constant using AISC member

[CameronEC]

AISC members have a warping constant (Iom or Cw) = 0 using the member from the AISC database. (see below).

But when I use this member with the CSA S16-09 design code, I get results that assign a value to Cw (see below)

Where is ROBOT getting the value of Cw?

Thanks,

[Artur.Kosakowski · Accepted solution]

It is calculated 'inside' the steel design module either based on formulas form the selected design code or the general ones for the declared section type. E.g.

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[Dirgs]

Artur,

This answer is also useful for my last post on Lateral Bucklyng of Tapered Section.

[locmelis_edgars]

Hello!

Is there an calculation formula how to calculate Iw for rectalngular cross section? I find for all cross sections except rectangular.

[Artur.Kosakowski]

  alpha=b-t

  beta=h-t

  Iw=alpha*alpha*beta*beta*(alpha-beta)*(alpha-beta)*t/(24.0*(alpha+beta))

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[michealasaad]

Artur.Kosakowski, Would you please provide the reference of that table? Thanks.

[Artur.Kosakowski]

Hi @michealasaad

It is from the Polish steel design code.

[michealasaad]

Thank you, @Artur.Kosakowski !

[pabmona]

I was trying to get a consistent method to calculate the warping constant (Cw) of closed sections and I wanted to compare it with an analytic formula. Could you tell me what is the source of the one you published here? It's easy to find warping constant formulas for open sections, not so much for closed ones. Thanks in advance.