built up member w/ radius

[JStructsteel]

Fabricator local to me cant bend a W12 beam (12x26) and want to just flame cut a web with the radius, and then roll plates to make the webs. Would you require a full pen weld, or just calc the fillet size to satisfy the shear. Based on quick calc, 3/16 fillet seems to work. Its a 22' span, Vu is 5.4K if someone can double check me.

Thanks

 

[KootK]

I'd be fine with the fillet welds rather than the full pen. In some respects, the less welding heat input the better for distortion etc.

 

[phamENG]

The fillets, if done well, will mimic the the fillets of a rolled section and could add to the "authenticity" of the appearance.

Strictly engineering, though, I'm with KootK. Though I might be hesitant on the flame cutting. Put together a solid specification for cut tolerance to make sure the final product will mate up with the flange for decent welds. That would go equally for fillets or CJP.

 

[r6155]

Search another fabricator.

Regards

 

[JStructsteel]

Thanks KootK, and PhamENG. This thing is lightly loaded, so I agree I can get away with less weld. Its all going to be covered up, so appearance not a issue.

Would you divide the welds up equally both sides?

r6155. Not an option, as I am just the engineer. Thanks though.

 

[phamENG]

Would you divide the welds up equally both sides?

All else being equal, I love symmetry - so yes.

 

[r6155]

Do not arruine a nice beam W12 x 26. Use plates of same thickness and weld with qualified welder.

Regards

 

[Lomarandil]

Another vote for both sides if accessible. Smaller welds are faster, cheaper.

Unless it was truly inaccessible, I'd require at least a ("non-structural") seal weld on the far side, even if a single minimum fillet was technically sufficient. Just to mitigate the weld being loaded in twisting about its axis.

----
just call me Lo.

 

[JStructsteel]

Thanks.

r6155 what do you mean by arruine?

 

[r6155]

Sorry. I say now ruin, spoil

Regards

 

[JStructsteel]

Got it. They are not ruining the beam, they are going to make a beam out of plate steel at the required radius shape.
Thanks

 

[KootK]

I like two sided welding here too. The pre-Eng folks do one sided welding on tapered columns sometimes. Some reasons that I'd avoid that here:

1) One sided welding provides less rotational restraint to the flanges.

2) For a one off thing, I'd not be interested in taking on that extra risk for very little gain.

3) Two sided welding may help even out lateral distortion.

4) As a curved beam, your flange will be either pulling away from, or pushing into the web. I love the snot out of that occurring symmetrically rather than eccentrically.