HSS-to-HSS 3 Branches Connection 1

[anewbieengineer]

Hi All, design guides and AISC manual do not provide an example that is similar to the following situation. How should we separate the branches into 2 sets of overlapped K connections for checking?

 

[r13]

See linked design guide, P101, Fig 8-3, case (f).

Link

 

[BAretired]

I suggest the connection shown below. The vertical HSS is carrying very little load, so HSS 6x4x1/4 is likely adequate, perhaps even HSS 4x4x1/4 would be okay. Having all three members with the same depth is not recommended because you will end up with a weld on the corner radius where the members intersect; that is not a good weld.

BA

 

[JLNJ]

Your joint is not in equilibrium. I' not sure if it matters to you.

 

[anewbieengineer]

Thanks for all the reply. Thanks for pointing out that the loads are not in equilibrium.
I am actually from the North, so preferably we do not want to change the member sizes at this stage (Detailing) unless it is really necessary. Understood BAretired recommendation of having the vertical to overlap the diagonals instead of the other way around, but I think they shop would prefer to have the vertical fitted first to square the top and bottom chords of the truss.

I managed to spend more time on this joint and did more readings. Would the following be the right way to break up the connection for checking?

And the sum of the utilization ratios of each pair of K and X check will need to be less than 1.

 

[klaus.]

you can design is using this programm

 

[anewbieengineer]

Hi Just wondering if anyone might have more advice on this, thanks!

 

[Agent666]

I haven't actually looked but maybe AISC design guide 24 covers this (I'd be surprised if it didn't provide some guidance on the matter?).

The other common documents to look at for hollow sections connection design is the CIDECT guides (all free downloads) here.