Warping constant for steel channel

[Polecat]

This subject was addressed in a thread a couple of years ago but never seemed to come to a conclusion.

I need to determine the limiting unbraced length and buckling moment of a steel channel section. I am using AISC's LRFD 3rd Edition, Chapter F, Section F2a, wherein it calls for the use of a term Cw, the warping constant of the member.

I can't seem to find a source to show how to calculate this.
Can anyone provide any data on this?

http://www.spiraleng.com

 

[VoyageofDiscovery]

Hi Polecat,

Try

http://www.iesweb.com/products/shapebuilder/

This program will allow you to find the Cw and other properties of any shape from imported dxf or its own database.

HTH

VOD

 

[prex]

Look in the first site below, under Beams -> Cross sections -> Channels -> Tapered -> Single: Cw is one of the quantities displayed for a number of channel standard sections.
If you choose Options -> Show formulae, you'll see the formula used for Cw.

prex

http://www.xcalcs.com

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[WillisV]

See Tables 1-29 and 1-30 on p1-96/97 of the 3rd edition manual for tabulated values of Cw and other flexural torsional properties of channel shapes.

 

[Polecat]

To VOD, Prex and WillisV:

Thanks so much for your quick responses. I've got my answer.

From xcalcs.com I got the formula for Cw and from Table 1-29 (which was obviously in my book the whole time --- I just didn't know where), I see all the properties that I need.

Much obliged, fellows.

http://www.spiraleng.com