Warping constant, H for lipped sections 3

[phuduhudu]

I am trying to do a spreadsheet to design a purlin section made of a back to back cold formed lipped channel and cold formed lipped angle. I need an expression for the warping constant (H in mm6) to do the calc. I have a reference which gives an expression for this for built up I sections but not for my particular case. Can anyone help? Carl Bauer

http://www.bauerconsultbotswana.com

 

[0404]

Go to "

http://WWW.rsgsoftware.com"

and download program "CFSCT". It can calculate the warping constant for you. Good luck.

 

[phuduhudu]

Thanks 0404,

That's a great little program and it answered my question but I am still concerned that I don't know the theory behind it. Can anyone point me to a reference?

Carl Bauer

http://www.bauerconsultbotswana.com

 

[Ingenuity]

Carl,

The reference "Design of COLD-FORMED steel structures" by Prof Greg Hancock is a good one, with a balance between theory and design.

It used to be available from the Australian Institute of Steel Construction, but my copy is dated 1988.

I am not sure exactly what you want in terms of "reference" but a book that describes the two components of torsion - uniform and non-uniform torsion - of steel structures should describe warping torsion and the derivation of the warping section constant. One good reference is "Bahaviour and Design of Steel Structures" by Trahair and Bradford - thinned walled sections are detailed in a chapter without too mnay differential equations.

HTH

 

[butelja]

Formulas for Stress and Strain by Roark & Young, 5th Edition has the formulas for warping coefficients of many types of sections in Table 21 of chapter 9.