Fabricating I-Beam
Fabricating I-Beam
(OP)
I have a supplier in Singapore that is having a hard time finding various size wide flange beams in low temp rated material. He has come back asking to fabricate the beams instead out of ABS EH36 material. This plate material is already approved by us and is used for many of the plate components of the job and he already has the necessary weld procedure also.
I know I have seen beams fabricated in the past, but I have never been directly involved. Is there anything special I need to look out for or special requirements I should impose? I was figuring that a full penetration weld with the necessary UT inspection would be acceptable, but figured I would pose the question hear and see if anyone had some guidance.
Thanks!
I know I have seen beams fabricated in the past, but I have never been directly involved. Is there anything special I need to look out for or special requirements I should impose? I was figuring that a full penetration weld with the necessary UT inspection would be acceptable, but figured I would pose the question hear and see if anyone had some guidance.
Thanks!






RE: Fabricating I-Beam
Mike McCann
MMC Engineering
RE: Fabricating I-Beam
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RE: Fabricating I-Beam
RE: Fabricating I-Beam
RE: Fabricating I-Beam
You might have to check the bending calculations. Depending on the code, to calculate the bending capacity you use a parameter which has different values if the section is rolled or welded (sorry but I do not remember the specifics and I do not have the code handy.
Absolutely no full penetration welds. It is not an easy weld (on 'T'), the heat distorts the flange and it is not required to transfer the shear stress. The calculation for the shear transmission from the web to the flange is quite simple and you will see that very little weld is required.
RE: Fabricating I-Beam
Thanks for the pointers.
RE: Fabricating I-Beam
RE: Fabricating I-Beam
I have made I-shapes from very large plates when rolled shapes were out of the question but nothing as small as W16 type plates. This will force the fabricator to pay attention in the welding process to meet tolerances.
Regards,
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RE: Fabricating I-Beam
In the past, in order to avoid the corrosion problem for built-up sections in marine environments, I have done the following:
1) Design the stitch welds as required -- for example, a fillet weld about half of the thickness of the web, and welded from both sides, to completely seal on both sides of the weld.
2) Open a gap between the web and the flange. If, for example, it's an 1/8th fillet of four inches long, with six inch spacing between each weld, cut a gap along the top and bottom edges of the web plate between the weld locations prior to fit-up. I usually put a generous radius of twice the thickness of the web to avoid sharp corners. (grind inside corners smooth)
3) Finally, weld along every part where the plates touch, being certain to weld closed each end of the stitch weld.
The description in number 2 may not have made sense, but what I'm describing is similar to how the web looks at the coped end when bolting (or welding) to a column. You just do that 20 or 30 times along the length of the web at top and bottom.
-T
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RE: Fabricating I-Beam
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RE: Fabricating I-Beam
RE: Fabricating I-Beam
RE: Fabricating I-Beam
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RE: Fabricating I-Beam
Dinosaur, thanks for the tips on the construction. The longest continuous piece we need is 44 ft. so it will most likely have to be spliced. We have spliced the beam in the past and we have a particular area that is very lightly stressed that is convenient for the splice.