Welded-Welded Shear Tab
Welded-Welded Shear Tab
(OP)
What do you do when bolt holes in a shear tab don't line up? (For those unfamiliar with the term, a shear tab is a plate welded to the supporting member and bolted to the web of the supported member.) Sometimes, due to fabrication or erection issues, the holes in the shear tab don't line up with the holes in the supported beam web. So the easiest thing to do is to weld the shear tab to the supported member, right? See the attached sketch. But then you have a connection that doesn't allow for any end rotation, so your model of a pinned connection is no longer valid. Indeed, AISC doesn't recognize this connection type.
My question is, does anybody know of any research or documentation on these types of connections? This is a common problem, and the common proposed remedy is "weld the shear tab to the supported beam web."
My question is, does anybody know of any research or documentation on these types of connections? This is a common problem, and the common proposed remedy is "weld the shear tab to the supported beam web."






RE: Welded-Welded Shear Tab
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RE: Welded-Welded Shear Tab
RE: Welded-Welded Shear Tab
Obviously an angle can be welded-welded and still flex.
RE: Welded-Welded Shear Tab
RE: Welded-Welded Shear Tab
In a field repair situation, I suggest that you look at the entire condition. Is this a beam to girder connection? Are the beams composite or otherwise limited from rotation? An alternate connection type may be necessary, but maybe not.
http://www.FerrellEngineering.com
RE: Welded-Welded Shear Tab
Single angles, especially bolted/bolted, are great for a CNC beam line shop. Prior to 13th Edition the connection capacities were greater for single angles. GOL=2 1/2" was less than the eccentricity using in a single plate. The beam and supporting members pass through the beam line for cut and holes. The single angles can be fabricated similarly. No shop welding is required, the angle is bolted to the support or beam web and is ready for paint or delivery. No labor fitting material or welding. CNC for the entire connection. Some beam lines can even provide the copes if necessary.
It is probably an unexpected bonus that a miss-fit can be field welded.
http://www.FerrellEngineering.com
RE: Welded-Welded Shear Tab
Also note, the ductility check refers to the supporting web or plate. This is also a very conservative limit on the plate thickness. I have attached a sample calculation of how we determine the plate thickness (ref 13th Ed p7-19).
http://www.FerrellEngineering.com
RE: Welded-Welded Shear Tab
KBVT, that response was pre-2005 Manual, so the extended configuration shear tabs didn't exist then.
RE: Welded-Welded Shear Tab
RE: Welded-Welded Shear Tab
RE: Welded-Welded Shear Tab
If the holes dont line up it must be pretty sloppy workmanship from the contractors or steelfabricators.
I wouldn't allow the use of welding of the joint, its sloppy doesn't look good and the joint doesn't do what it supposed to do.
Further I would be investigating why the holes dont fit and closely look at all workmanship in the whole project and I guarantee you will find many more serious issues.
RE: Welded-Welded Shear Tab
Plug welding and redrilling can have additional problems. The weld metal can cause the drill to drift and create a no conforming hole.
http://www.FerrellEngineering.com
RE: Welded-Welded Shear Tab
Fair enough !
But I still would not allow a welded joint in Lieu of the bolted joint.
RE: Welded-Welded Shear Tab
RE: Welded-Welded Shear Tab