HSS Beam to HSS Column Weld

[BadgerPE]

I have a situation where the client is requesting an HSS 12x8 outrigger be welded directly to the face of an HSS 12x12 column. Assuming that all of the checks work out on the column, (plastification, etc.) is there anything inherently wrong with a connection like this? Due to the applied moment at the beam/column interface, I am assuming it will need to be a full-pen weld to develop the required flange strength. This is a roof so gravity snow loading is controlling the design. Furthermore, it is in SDC B so not a lot of special requirements to meet.

 

[jdgengineer]

Nothing inherently wrong with it. Full penetration welds with HSS shapes are a bit difficult but not impossible to complete. If possible, it would be better to increase the tube wall thickness to allow for a partial joint penetration weld, or to increase the size of the column to allow an all-around fillet weld of the outrigger.

 

[KootK]

Normally you don't develop the full flange yield strength because column wall strength won't take you that far anyhow. So a full pen weld is not likely to be required. If you don't need this thing to be pretty, equal width members with some fillet welded side plates makes for an easy and robust connection.

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.

 

[wannabeSE]

Is the 12x8 outrigger flat? I assumed is it 8" wide and 12" deep. If it is 8" wide, I would try to get fillet welds to work. If the columns can't handle the connection forces, through plates are an option when nothing simpler works

 

[BadgerPE]

Thanks for the help. It does need to look pretty and I needed 1/2" fillet welds (per RISA Connection - haven't back checked it yet) so it sounds like a partial pen might be the way to go. The outrigger is 8" wide so there is room to weld to the flat of the column all the way around

 

[jdgengineer]

1/2" fillet will likely be much preferred over the full pen weld by the contractor.

 

[slickdeals]

I typically try and size the tubes smaller so that I can get a all-around weld around the column. You'll still need to check for all the HSS wall bending etc.

 

[BadgerPE]

jdengineer,

This will be shop fabricated for aesthetics and ease of erection. Does the 1/2" fillet weld thought still hold true or would a partial pen be better in that situation?

 

[KootK]

Much better. Less prep and easier inspection.

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.