Moment Connection W beam to HSS round tube

[SperlingPE]

I am looking for resources for moment connection design for W beam framing into a round HSS. The round HSS is a corner column. The W beams frame into the column in 4 directions. Two of the beams are cantilevered. The other two beams are supported at their other end. In addition, there is another beam above these four that is cantilevered and is at a 45 degree angle between the other two cantilevers.

The cantilevers will have dead load and live load roof moments. The two non-cant beams will have lateral load moments (wind or seismic).

 

[JAE]

I don't think AISC 358 allows pipe columns in prequalified moment connections to resist seismic forces so you would be stuck with an ordinary moment frame system.

I don't have anything specifically at hand for how you'd detail that type of connection. The cap plate of the column could, of course, be used to tie in the top flange. The bottom flange connection to the column would be the difficult part.

 

[hokie66]

I would have thought the beams would take preference, the columns would have cap plates and base plates sized to take the column bending, and the beam connections would then be normal moment connections, with stiffeners to transmit the column vertical load and bending. This would avoid having to install internal stiffeners in the circular hollow sections. The 45 degree beam above complicates things, and one way of doing that would be to shop weld in the through section of the beam with the upper column. Maybe the cantilevered part could be shipped with the column, depending on the size for shipping.

 

[jdgengineer]

If you are in a high seismic area I don't think this is allowed. Alternatively, I believe you can use a built-up box shape or a cruciform I shape.

If you are not in a seismic area it may be allowed. However, how do you weld the beam to a pipe section? Do you shape the beam flanges around the circular pipe? Sounds expensive, but I'm not an expert. Maybe the architect can fur out the section to a circular pipe in lieu of using one as a structural member?

 

[SperlingPE]

Not in a high seismic area and most likely will not control the lateral force design.

The column does not have to be round. I was thinking round because of the 45 degree upper beam. I could do a square tube with a beam coming into each face and the upper beam comes into a corner.