Cw 1

[dgkhan]

Torsional warping constant.For certain hat channel section, I can draw in section wizard and can obtain all values except Cw. How to manually calculate it.

 

[ishvaaag]

As per former code NBE EA-95 Anejo 4 (in spanish)
Ia=Cw

 

[ishvaaag]

A close example in a Mathcad 2000 worksheet, one U-lipped section (like a lift core without door headers). For open sections; change the geometrical coordinates in the input and you have one hat section. Below will include a pdf printout.

 

[ishvaaag]

The printout.

 

[prex]

In the first site below, under
Beams -> Cross sections -> User defined -> Torsion: from dxf
there is a sheet for calculating torsional properties of any section defined by a drawing.
Roark has a formula for a hat section, not sure whether it is exactly what you are looking for.

prex

http://www.xcalcs.com

: Online engineering calculations

http://www.megamag.it

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http://www.levitans.com

: Air bearing pads

 

[BAretired]

The method of calculating Cw is given in "Cold-Formed Steel Structures" by Wei-Wen Yu. Expressions for hat sections and other cross sections are tabulated in Appendix B.

BA

 

[dgkhan]

I am not familiar with mathcad. Does any body has in Excel or any formula for hat channels.

 

[BAretired]

See attached.

BA

 

[wannabeSE]

A quick search of the internet provided an article on calculating the warping constant.

http://www.ceric.net/kssc/KSSC_3_2007_7_4_297(C).pdf

. I have not read the article, but it looks interesting. For hat channels, the article has the same formula as AISI's Cold-Formed Steel Design Manual 2008 edition.

 

[dgkhan]

section wizard does give Cw Value also.It lists it as Iw = Sectorial moment of inertia

 

[jameslord]

dgkhan, i am using ShapeDesigner Saas (

http://www.mechatools.com)

to compute torsion, warping properties and related stresses, is really simple and efficient and for the price is really interessting it costs me only 99$. hope this helps. and good luck.