I-beam made of plates

[Chavita]

Hi everyone,

I haven´t been able to find a vendor within the USA of structural shapes (I-Beams) in materials such as ASTM A 36 Mod 1, ASTM A 131 GRADES CS, D AND E, or ASTM A633 GR. A.

First question: do you know a vendor of this materials?

Because I havent found those materials, now I want to fabricate the wide flange beams from plates. I might be helpful to tell you that this fabricated beams will be used for the roof structure of a a Refrigerated Tank acording to API 620 apendix R. This means that the operating temperature is around -50° C.

Second Question: do you know a standard, code, manual, web page or something dealing with the procedure for fabricating beams from plates?

Third Question: What type of welding electrodo would be the most appropiate?

Forth question: (and last one), what other provisions should be took?

thanks a lot.

 

[HgTX]

HgTX (Civil/Environme) 22 Sep 08 13:42
For wide-flange sections in the U.S., try ASTM A 992 rather than A 36, unless you were specifically counting on the upper limit on tensile strength that A 36 provides. A 992 does provide an upper limit on yield strength. A 992 has become the default material for W-beams for structural use. If you are concerned about toughness at low temperatures, order ASTM A 709 Gr. 50ST to Zone 3 requirements. (Same properties as A 992 but with Charpy testing.) You'd still need to specify the fine grain practice and Mn limits of Mod 1.

The applicable welding code is probably AWS D1.1.

Try starting here:

http://aisc.org/Template.cfm?Section=Steel_Availability

Hg


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[Chavita]

Hi HgTX,

We want to use ASTM A 131 Gr. E for these Built up I beams, because that is one of materials listed in the standar.

For some reason the link didn´t work in my pc.

Greetings.

Chavita

 

[HgTX]

The link would be for finding someone who makes the rolled sections. If it didn't work, try getting to it from

http://www.aisc.org/

and then clicking on "Steel Availability" in the upper left corner.

Hg

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[DRC1]

AAsHTO specifications detail the design of girders from plates ASC dicusses it too, but not to the same extent Design of Welded Structures by Blodgett also has a lot of information on designing plate girders. Don't know about ASTM 131, but for A36 7018, a low hydrogen rod is typically used for bridge work.

 

[msquared48]

Check the latest AISC Steel Construction Manual pages 2-213 through 2-242 for the design of built-up, or plate girders.

As for the cold, I would provide a slip joint connection at one end to allow for thermal contraction in the structure.



Mike McCann
MMC Engineering