Question regarding HSS single angle connection to another beam (Shear only)

[Orsted]

Hi,

Due to some reasons using clip angle for the HSS isn't possible and is instructed to use HSS single angle connection (welded or bolted) to the other beam.

The load transmitted will only be vertical shear I'm wondering if will there be any issue or additional checks required especially for the angle since it might twist or something close to the idea?

The load isn't that large around 5 kips.

[Edited] Here's the sketch. Cant seem to attach it.

https://files.engineering.com/getfi...4-7d4d-4478-8ae5-e3b3f9a4dd03&file=Sample.pdf

Thank you.

 

[BAretired]

Provide a sketch showing the orientation of the single angle to the HSS.

BA

 

[KootK]

I think that you're fine given that:

- it's a light load.

- it's a fairly high aspect ratio HSS.

- Your treads and risers probable resolve much of your torsion.

- You've probably got your angle on the inside of the stair such that the shear is delivered to the same web that gets connected to the support. Ergo no need to move the shear across the width of the HSS through flange bending. In this sense, one could sort of visualize the member as a channel rather than a tube.

 

[BAretired]

I don't like that eccentric connection. Section A does not show the condition near the web of the beam where the top and bottom of the HSS is removed. It might work, but there would be some strange twisting and distortion in both the HSS and connecting angle which would be difficult to analyze.

An end plate welded to the HSS and bolted to the beam web each side of the HSS would be a more typical and much better connection.

If you don't have sufficient clearance for that, an HSS stub or double plate fitting between the walls of the HSS could be welded to the web of the beam and bolted through each vertical wall of the HSS providing a symmetrical connection.

BA

 

[SteelPE]

I'm not sure I do this right, but if I were to look at that connection I would break down the connection to see what will take shear only and what will take shear+moment or shear + torsion. With single angles like this, I typically say that the heal of the angle is in pure shear and then design the weld to the HSS and the weld to the supporting members taking shear+moment or shear + torsion. I suspect you can justify the connection with the low loads you have, but you should still check the connection as this one is particularly ugly.

 

[TehMightyEngineer]

I'd personally change the angle to a single shear plate connection. However, as long as you check the added torsion on the weld I suspect there's no reason this can't be make acceptable with a sufficiently stout angle. As KootK noted, this doesn't strike me as much different than a channel stair stringer connection.

Ian Riley, PE, SE
Professional Engineer (ME, NH, VT, CT, MA, FL) Structural Engineer (IL, HI)

 

[Orsted]

Thank you all for the responses. I proceeded in using the single angle and designed the weld including the load induced by the eccentricity.

 

[sbisteel]

If it were me I'd weld an end plate to the end of the coped section, and extend the end plate to the side with (2) holes for the eccentric bolted connection. This way you would have both vertical walls of the tube engaged in the end connection.

 

[BAretired]

An eccentric end plate is definitely an improvement on a single HSS vertical wall connection.

BA