Cold formed Z & C sections - table of properties / plastic & Elastic section modulus 1

[fearghusq]

Hi guys.

Im doing some work on retrofitting of 70 warehouses - new roof enslosures & roof mounted plant.

Im going through the process of capacity checks on existing purlins - vary from site to site.

I need table of properties for them - much like we would use for normal heavier steel sections.

Im working in Australia but am trying to use Design Spreadsheets I built for design to Eurocode - put cant get the section rpoperties table I need and its a pain in the Arse to calculate them from scratch for different sections and sizes.

Cheers folks

PS Is there any reliable free software package out there for cold formed/light gauge products? Even if its to ASTM, BS, EC or whatever major standard?

Most of what I have built myself is for regular steel (RSJs, Universal BEams, Universal Columns, CHS, RHS, etc)

 

[ajh1]

CFS by RSG Software is a good cold-formed package, but it's not free. There is a trial version that is free, but does not have save or print capabilities. It handles many of the cold-formed specifications. Australian cold-form is very close to US AISI, so using AISI options should give you satisfactory results.

 

[MiketheEngineer]

Don't know about AU - but in the US many(most) of those purlins were proprietary in nature - trying to save nickels and dimes - so no positive info available. Even wehn analyzed - they don't often show so good. I think they did field testing to prove soem of them

Good Luck.

 

[rb1957]

basic section properties are easy enough to work out by hand, no?

divide the section into basic shapes (rectangles, arcs) then
x y A = x*y ybar A*ybar A*yabr^2 Io = x/12*y^3
and yNA = sum(A*ybar)/ sum(A) and I = sum(Io)+sum(A*ybar^2)-sum(A)*yNA^2

plastic properties ... divide the section into two equal areas

 

[SteelPE]

I know an engineer who does a bunch of work similar to the work you are describing. He was the chief engineer at a large metal building mfr for a while and now he does consulting work on his own.

Mike is correct is stating that they did full scale test. This is part of the spec in the back of the AISI (section D6 in my AISI) where they have these mysterious R values. I believe these tests were conducted by Fisher but I am not sure.

The other engineer absolutely loves the RSG software and is always trying to get me to use it. He only uses the free version to calculate Se I believe.

 

[beemer218]

Check out the MBMA (Metal Building Manufacturers Association) They print a list of section properties for Zees and Cees. Also, my copy of the RSG demo software will print but you cant save. This is a very good tool for light gage.

 

[reddy100]

You can try STRAP Software. Using STRAP-CROSEC module you can create any shape of cross section and make it parametric. Using CROSEC user can create a database of their sectional shapes for optmisation. You can check out more information at the following website

http://www.atirsoft.com

You can have 30 days free trial verision with all options with out any restrictions.

 

[hokie66]

As you are in Australia, the purlin section tables are freely available from manufacturers. The Lysaght (or Bluescope) and Stramit tables are comprehensive for shapes used in Australia.

http://www.lysaght.com/structural-products

http://www.cadtech.com.au/Products/STRAMIT/PTM_PurlinsGirtsBridging_V0[1].1.pdf

I don't see the point of trying to use Eurocode provisions for purlin analysis in Australia. The load tables used here are based not just on calculation, but also on extensive testing.