Cold-Formed Steel Properties

[MCurry]

I've got to add some cold-formed steel joists to my model. The standard material properties spreadsheet only includes A570 and A607 steel. These are outdated specs as far as I know. Are others just creating their own material on the spreadsheet? Those specs were apparently superceded by A1003 (I think) in 2000. That's 10 years ago! Seems like enough time for Risa to pick up the change, eh?

 

[JoshPlumSE]

The problem here (at RISA) is that we are not in the day-to-day business of designing structures and putting together construction documents. Therefore, we don't necessarily keep up on some of the misc details of the profession... like which of the 15 or so of the ASTM material specifications for cold formed would be most useful for our users to have as their default values.

Those material defaults originally came directly from user feedback on a previous version. But, was obviously done some time ago. We haven't had a whole lot of user feedback suggesting which 2 or 3 materials we should switch to for our defaults.

I suppose that most people are probably just entering in their own materials.... After all, it should just be a matter of changing 2 or 3 input fields (name, Fy, Fu).

 

[JoshPlumSE]

I should point out that I'd love some feedback on which (of the 15 mentioned in the AISI steel spec) would be considered the most common or useful materials for a structural engineer to have in the program.

Hopefully, we're just talking about 2 or 3 of the 15.

 

[MCurry]

Well thanks Josh - good to see your voice again! And thanks for checking in on the forum and responding.

As far as I know, the latest AISI steel spec is ASTM A1003/A1003M-02a "Standard Specification for Sheet Steel, Carbon, Metallic, and Non-Metallic Coated for Cold-Formed Framing Members" as referenced in the latest AISI Standard "North American Specification for the Deisgn of Cold-Formed Steel Structural Members, 2001 Edition", and the always popular "AISI Standard for Cold-Formed Steel Framing - General Provisions 2004 Edition"

I don't have the spec (I hardly ever use cold-formed members) but the abstract said the spec includes:
"The steel sheet is available in the following designations: Structural Grade 50 Type H (ST50H), Structural Grade 340 Type H [ST340H], Structural Grade 40 Type H (ST40H), Structural Grade 275 Type H [ST275H], Structural Grade 37 Type H (ST37H), Structural Grade 255 Type H [ST255H], Structural Grade 33 Type H (ST33H), Structural Grade 230 Type H [ST230H], Structural Grade 50 Type L (ST50L), Structural Grade 340 Type L [ST340L], Structural Grade 40 Type L (ST40L), Structural Grade 275 Type L [ST275L], Structural Grade 37 Type L (ST37L), Structural Grade 255 Type L [ST255L], Structural Grade 33 Type L (ST33L), Structural Grade 230 Type L [ST230L], Nonstructural Grade 33 (NS33), and Nonstructural Grade 230 [NS230]"

That's a lot of options, as you said. Dietrich uses 33, 40, and 50 ksi yield strength steel. I'll leave it to someone more familiar with cold-formed steel design to say what designations are most common.
I just got confused when I saw that the A570 and A607 specs don't exist anymore. After looking all this over, I wonder why I never design using light gage steel?;-}
I'll follow your suggestions and just plug in values for the later specs - once I figure out which one to use :-/