HSS to HSS sleeve connection 1

[EngrRC]

Does anyone know of any guidance relating to moment connection between two hollow steel section beams, one beam (smaller tube) snug fit inside the other (bigger tube) by some contact length?

I imagine that bolts, when used to connect the two, would only resist axial loads to prevent them from separating. Or would the bolts resist some moment due to unavoidable fabrication tolerances, i.e. snug fit in only localized areas within the contact length?

 

[BridgeSmith]

It would have to be inserted far enough so that the bearing load at the end of the larger tube doesn't tear it.

There may be some moment resistance from the bolted connections, but it would be nearly impossible to quantify.

It could be considered a moment resisting connection, but even with a very snug fit, there will be some amount of rotation of joint before full moment capacity is reached.

 

[haynewp]

If there is slip then there will be a couple produced with a magnitude of the concentrated forces based on the insertion length. I would also check local HSS wall crippling at these contact points. There may be some similar cases to check this in the HSS guide by AISC. But I don't know of any guidance that specifically addresses your scenario.

 

[dauwerda]

Moment resisting slip-fit connections are used for bent plate tapered tubular poles (8 and 12 sided) in the transmission industry all of the time. While this is not quite the same thing it may be somewhere to start at least.
ASCE 48 provides guidance on the design of these connections. To develop the full moment capacity it requires that the lap length of the two sections be at least 1.5 times the inner diameter (flat to flat) of the female section. This requirement is based on full scale testing performed by Sumitomo Steel in Japan in the 70's and by EPRI in the US in the 90's (per ASCE 48 commentary).
The connection's main difference (that I see) would be the taper, the two tapered pole sections are jacked together using around 30,000 lbs of force when assembled.

 

[OldBldgGuy]

Pre-engineered picnic shelter, gazebo, etc. type buildings use this type of connection, pursue it through them.

 

[Agent666]

This example of a telescopic boom is sort of along the lines of what you are after, though I note they don't specifically check the bearing on the tubes in combination with bending (which would be required when working to the standard noted, at least there are provisions for it). However they go through some of the general checks on the section, load transfer between the sections and various things that you can probably relate back to similar checks undertaken to whatever code you are working to.

 

[EngrRC]

Thanks Agent666 for the file. SO what they did was to resolve the moment into equivalent force-couple. They did have a long contact length though (1.7m)