All Welded End plate connection??

[lindsaylu]

I am looking at an existing structure requiring rework for expansion. The connection in question is between a W14X48 beam coming in on a 30deg angle to a W16x65 girder. As this is an existing structure we'll be field welding at heights. The best connection I can come up with is a welded/welded end plate. If I don't provide a return at the top of the plate, but do at the bottom do I have enough flex in the plate to provide a pinned connection??? Any better ideas?? I can see how I'm going to get a mag drill in there to bolt the end plate and I also don't fully trust the existing conditions enough to try to fab a double bent plate connection at that angle.

Thanks!

 

[XR250]

Why do you need a pinned connection? The 16x65 will likely just twist to acomoodate.

 

[racookpe1978]

Draw the problem please! Unfortunately, I can't visual it clearly enough to help, particularly since you asked about clearances.

 

[lindsaylu]

Ok I've drawn up the detail for the connection... let me know what you think. Factored loading of 70k vertical. 1/2" plate is due to available plate at the facility.

 

[StructuralEddie]

The issue has been raised before. Search for all welded shear tab or the like on this site for the discussion. The conclusion was AISC doesn't detail it out in the manual because of the difficulty of the shear tab obtaining the require flexibility for a simple support.

 

[JoshPlumSE]

Some thoughts:
1) You'll be introducing a torsion in the girder due to the relatively large eccentricity of this connection. So, you want to make sure the girder can accommodate it or that deck and other beam connections could eliminate it.
2) I'm not a welder, but that looks to me like a challenging weld to make. So, you might check with a fabricator / erector to make sure that it is feasible.
3) What about a bent plate connection bolted (or welded) to the girder web? I would think this would be a little more flexible. And, it wouldn't have as much field welding.

 

[StructuralEddie]

Is bolted/welded an option?

 

[a2mfk]

It's ugly no matter how you slice it. Agree with everyone that you have to do one of the two connections as bolted to avoid transfer of moment into the girder.

W14x48 isn't all that heavy, can you make a W12 work which buys you room for a seated beam angle connection that is welded to the girder and bolted to the W12? This gives them quite a bit of flexibility in regards to the skew angle. Also, almost always better to upsize a column or beam and avoid stiffener plates. Also a W12 would avoid the bottom cope and along with being a heavier member may resolve that issue. Although after looking at your detail again maybe it is the top cope and the long unsupported web that is causing shear/buckling issues with the web.

 

[connectegr]

Why not use a simple bent plate connection? Shop welded to the girder or beam, and field bolted.

http://www.FerrellEngineering.com

Providing fabrication and erection efficient structural design of connections. Consulting services for structural welding and bolting.

 

[connectegr]

As a bent plate connection, welded to the girder with an "L" weld and a return, the connection material will provide a "flexible" connection. These connections are very common. As you have shown, the web doubler may be required for the coped section reinforcement. But, the plate can be field bolted to the beam web, through the doubler. Make sure that adequate clearance is provided to install the bolts. And, two columns of bolts may be required for 70 kips, with the eccentricity.

http://www.FerrellEngineering.com

Providing fabrication and erection efficient structural design of connections. Consulting services for structural welding and bolting.

 

[ul92]

That is my suggestion:

Weld the plate (1/2'' x 10'' x 12'') that is shown in section E-E to the beam (I would made a longer one). Add two stiffener plates (not thicker plantes than web material) ahead and two ones behind of the beam. Remain double plate on the girder.Add perpendicular stiffeners beneath of it. Drill and bolt it. Calcuation procedure is shown in most structural books.