Offset Skewed Shear Tab on Column Flange 1

[ksellc73]

I have a condition where I would like to connect a skewed beam into the column flange with a single shear plate connection. The only problem is that the center line of the beam is on the center line of the column so where it contacts the flange will actually be offset from the center of the flange. How do I consider the offset of the shear plate on the flange? Is there a better way to handle this condition? Hopefully the attached picture will help clarify what I am asking. Thank you.

 

[bowlingdanish]

I would consider the eccentricity of the connection in both directions. You will have induced biaxial bending in the column due to the offset fin plate. Depending on the load you may also want to web add stiffeners to the column to ensure no local deformation effects.

 

[KootK]

I agree with BowlingDanish on the eccentricity in both directions for the macroscopic design of the column. In my experience, this connection usually goes like this:

1) use an obtuse angle bent plate angle rather than a single plate. Three sided welding.

2) for a shear only connection, local bending effects on the column flange seem to typically get ignored.


I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[ksellc73]

Thank you for the input. This is a shear only connection. In this case I will only be responsible for the connection design which I am submitting back to the EOR who has done the column design.

KootK, I like the idea of a single obtuse bent plate welded to the flange of the column. I was considering that as well as an angle seat for some other options for this condition. Now that I think about it there are going to be several other advantages with your suggestion. Thanks again.

 

[KootK]

You're most welcome ksellc73. The only complaint that I have with the bent plate is that, to my knowledge, rotatational ductility hasn't been investigated rigorously as it has with some other connections. Welding the top of the bent plate obviously reduces rotational ductility relative to, say, a double angle clip connection. But, then, bending flexibility in the column flange and torsional flexibility in the outstanding plate leg probably add some ductility back in.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[thaidavid40]

It may be too late now to consider this, but could the offset beam be mover over a foot or so to the side, so it can frame into a beam framed into the column web?
Dave

Thaidavid

 

[ksellc73]

This beam is part of an exterior facade and it is my understanding that they have poured all the anchor bolts for this framing already. I don't think moving the beam is an option at this point but thank you for the suggestion.

 

[hokie66]

Depends on the magnitude of the reaction relative to the column capacity. If the reaction is relatively small, then the connection as drawn should suffice. If it is a big beam, then some stiffening should be done to the column.