Cantilevering beam over column with cap plate.

[Christos Panayi]

Hi All,

I am working on a small project of extending first floor of a shop. The extension consists of steel sections and more specifically in one location of the extension the beam will be bolted on an existing concrete beam at one end, then it will span over a column using a column cap plate and it will be cantilevering for 2.0m (6.5feet). Both beam and column will be IPE200 sections and at the point of connection between the two sections the moment will be 30kNm and 60kN in shear.

The column cap plate is 12mm (similar as flange thickness) and it will be welded all around to column and bolted to the beam with 4no. M16 bolts. Also, there will be beam stiffener plates of 12mm aligned to column's flanges.

Can anyone explain how to check the connection? I know that it will work. However, I would like to know if my checks are in the right direction.

I have broken the moment into beam's and columns flanges and using these forces I have checked:
1. Minimum web thickness using von mises criterion
2. Column's cap plate tensile capacity
3. Bolts in shear
4. Weld shear length.

Let me know if my checks are valid and if anything else needs to be checked.

Thanks

 

[271828]

The AISC Design Guides 16 and 24 have examples of these types of connections.

 

[Christos Panayi]

Thanks, I am based in Europe though and I have no access to AISC Design Guides though

 

[Agent666]

Have a look at the SCI P358 design guide, it covers quite a few configurations of full depth end plates for beams, and cap plates for hollow sections that might give you some guidance for your situation. Link

Note also for this type of connection of you are also reliant on the column providing twist restraint to the beam for lateral torsional buckling purposes that you also might need to review the connection to transfer the usual (2.5%?) proportion of the flange force acting at a lever arm of the beam depth to create a moment about the minor axis of the column (connection is subject to this load).

 

[Christos Panayi]

Thanks Agent 666, so I will take 2.5% of the beam's flanges force and perform the same checks. i.e cap plate compression capacity, beams in shear, bolts bearing and weld length.

So, by thinking about your comment, now I have one more question. When I break the moment into flange forces in the major axis, I have top and bottom horizontal force in the beam's flange as well as a positive and negative vertical force in column's flanges. When the same check is performed in the minor axis I will again break the moment into horizontal forces in the beam flanges. However, how is that moment transferred to the column?

Thanks