Cold Formed Steel section properties

[transmissiontowers]

I need to analyze a metal building for a beam load of a cable tray on a Cee 10x3.5x12gage and was looking for something that listed the section properties. This is a lipped channel made from 12 gage sheet steel. Is there somewhere that properties are listed or should I just calculate them myself? If I ignore the lip and assume the corner is sharp, will this be conservative?
TIA

 

[JAE]

I believe that the "CEE" designation is from Dale/Incor which can be found here:

http://www.daleincor.com/

Although at the moment the site doesn' seem to be working. They use the CEE label and I think the website has pdf's of the shape properties.

 

[whyun]

See is this is a standard section listed in the SSMA literature.

http://www.ssma.com/ssmatechcatalog.pdf

 

[whyun]

is = if... Is there a way to edit your previous posts??

 

[UcfSE]

http://www.marinoware.com/pdfs/structural.pdf

Look for the 1000S350-97 under the SSMA heading. Make sure you are checking according to the cold-formed steel specification by the AISI and not the AISC manual. They are not the same. Do not just use the "Ma" value out of the table. That does not account for laterally unbraced sections. A 12-gauge stud with a 3.5-inch flange shouldn't have a lot of loss due to LTB if you have a reasonable unbaced length but you still have to check it.

I don't know why the dale/incor site is down and I don't have my catalog here with me to look it up. It's worth it to keep trying their site but I think it's been down for a little while now.

 

[transmissiontowers]

Thanks for the links guys. The CEE 10x3.5x12Ga is used as a beam and spans 28 feet. It is in a 1992 Copperstone metal bldg in Houston. The drawings we do have (Coperstone is out of business) seem to indicate that the beam was capable of 72 pounds per foot uniform load. These Cee's are spaced about 5 feet apart and will support some cable trays that will be attached to the top compression flange. Do you consider the cable tray as a bracing point? It must be since there are no other bracing for the 28 foot span. Each CEE will support about 300 pounds of cables at 3 locations.

I am a little out of my element with these cold rolled shapes. I usually design Transmission Towers and Substation Structures and we brew our own form of LRFD where we apply an overload to the loads and design all the way to yield. Any helpful pointers will be very welcome.

A storehouse of worthless information.

 

[JAE]

whyun -

no way to go back and edit - unless you are a really bright engineer with time travel conquered....but you know that those odd quirky posts give this site character!

 

[miecz]

I have a Dale/Incor Catalog published in 1991. It lists properties for 10 inch CEE's but not for 12 gage. Properties are listed for 14, 16 and 18 gage only.

 

[UcfSE]

My dale/incor lists 1000S350-97's. Dale/incor calls these "SCJ" - Super C Joists. CEE is for the 1.625-inch flange. In the 2001 joist load tables a 10 SCJ 12 can take 84 plf of total load at 28 feet, and 56 plf live load where the live load deflection is limited to L/360. That is for continuous bracing of the compression flange however. You really need to have bracing for the studs' compression flange. Long unbraced lengths for metal studs really kill them. At 28 feet unbraced you'll loose about 85% of the strength you would otherwise have. If you can't brace your section you'll need to get ahold of the AISI spec to be sure you're ok.

 

[JAE]

I would think that 28 feet of unbraced length for a CEE would basically render the joist/stud incapable of taking any load.

 

[transmissiontowers]

Thanks for the pointers, I'll check it out.

_____________________________________
I have been called "A storehouse of worthless information" many times.

 

[whyun]

Thank you JAE, for the confirmation. Sometimes, when we're not too careful, we get quoted in the "Engineering Language/Grammar Skills" forum. Actually, it is good entertainment.

 

[miecz]

transmissiontowers-

Found properties for a 10"x3.5"x12ga Stiffened Channel in Table 1 of Section V of the AISI Manual. If you are still interested, let me know.

 

[transmissiontowers]

jmiec;
I found the properties in this link

http://www.marinoware.com/pdfs/structural.pdf

that UcfSE provided above. I computed my max moment for the beam and found that the max stress is about 17ksi (calcs are at work, I'm at home now) and the cable trays will brace the compression flange every 4 feet. I don't have an AISI manual and was wondering if buckling will be a problem? Is there a place on the web to look?

_____________________________________
I have been called "A storehouse of worthless information" many times.

 

[UcfSE]

I don't have any links to the AISI code online. Here are some research publications (free) that may help with understanding if you get time to read them.

http://ceeserver.cee.cornell.edu/tp26/TWResearchGroup/research reports.htm

This link is from the Dietrich website.

http://www.dietrichindustries.com/Onlinespecs/cdconversion/ststudadv.asp

It is a basic stud sizer to help with wall framing. If you play with it enough you might be able to find the equivalent load that provides your design moment and check your members. It could at least be a free and easy sanity check until you get the code you need. At an unbraced length of 4 feet I doubt you'll have any LTB issues but you should check per the code. Will those cable trays be able to brace the stud at 4 feet for the whole length? I would be leery of that unless you are very confident that is a correct assumption.

 

[transmissiontowers]

Thanks for the links. The cable trays are 30 in wide and there will be 5 of them, plus there are already 2 up there that are 4 feet wide so the dist between them that is unbraced should be less than 4 feet since the beam is about 30 feet long.

_____________________________________
I have been called "A storehouse of worthless information" many times.