Round HSS Local Checks - Atypical Case

[EngDM]

Hey all,

I've got a connection to an HSS pipe that I'm trying to analyze but not really sure where to start.

Picture a 4"Ø pipe being supported by a channel, where the pipe is in contact with the flanges of the channel, almost like it's sitting in it. There is a lateral force perpendicular to the pipe, so the channel flanges will push towards the pipe wall. Channel will be welded to the pipe on the flanges, either a fillet or perhaps a prep'd edge to make sure my fusion face is wide enough on the channel.



Other than the K2.1 HSS plastification check, I'm not sure what else I should consider.



One concern I have regarding the K2.1 equations, is that the plate in my case would not be about the pipe central axis', but rather 1/3 from the top edge approximately. Since the load from the pipe is from the centroid, I will need to resolve a moment as well as the shear loads (reactions shown in blue in my sketch above); this behaviour isn't explicitely covered by K2.1.

 

[KootK]

Will the load on the pipe be concentrated or distributed? That will affect whether or not the load of the channel pushing back on the pipe will be concentrated or distributed.

If the load is distributed, I'd be inclined to not sweat this too much.

One concern I have regarding the K2.1 equations, is that the plate in my case would not be about the pipe central axis', but rather 1/3 from the top edge approximately.

Maybe design the pipe wall foe the component of the load that is radial, as shown below. If you can get it all done on the compression side, so much the better.

Since the load from the pipe is from the centroid, I will need to resolve a moment as well as the shear loads (reactions shown in blue in my sketch above)

Depends... what is the condition of torsional restraint at the ends of the pipe and the ends of the channel?

If both members have torsional end restraint, I would expect the torsional stiffness of the pipe to dwarf that of the channel.

 

[EngDM]

Will the load on the pipe be concentrated or distributed? That will affect whether or not the load of the channel pushing back on the pipe will be concentrated or distributed.

If the load is distributed, I'd be inclined to not sweat this too much.


Maybe design the pipe wall foe the component of the load that is radial, as shown below. If you can get it all done on the compression side, so much the better.



Depends... what is the condition of torsional restraint at the ends of the pipe and the ends of the channel?

If both members have torsional end restraint, I would expect the torsional stiffness of the pipe to dwarf that of the channel.View attachment 4732

Pipe is being hung from typical pipe brackets, this is just the support near a bend for the thrust. I thought about doing the radial component, and it is surely conservative. It's loaded along an 8" length, so I'm sure it is okay just wanted to make sure my thought process is sound for if I ever check something similar with a higher and less trivial loading.