Roof screen post connection

[Veer007]

Hey Guys,

See a below snap, would it arrest 15kN.m moment force shown? let me know your thoughts, somehow the connection proposed for avoiding field weld. I know if it is welded then no issue, but for bolted?

Thanks in advance!!

 

[dauwerda]

It's not clear what you are asking. I don't see a moment force shown?

 

[KootK]

Pretty sure it's this. Small moment but, then, getting it done with only two bolts closely space. I don't have a good feel for it but it should be an easy check by OP to see if it's got legs.

 

[phamENG]

15kN-m is written in small print just below where KootK put his moment arrow, so I think that's probably accurate.

I don't really like it. You say the bolts are to avoid field welding, so it sounds like you have shop welded angles on both sides. Is this a slip critical condition, or is the screen allowed to rock back and forth a bit? I don't think you can achieve slip critical with this - to do so, you have to either get the angles placed with inhuman precision, or you have to bend them in to make sufficient contact with the vertical while also not crushing the vertical (which is always a concern with through bolted connections to HSS). You may be able to achieve a semi rigid connection with sufficient rigidity under service loads but at ultimate winds it'll lean over a little and be resisted by bolt bearing. Even with that, the bolt spacing is pretty tight.

What about making it all one big shop fabricated weldment? Might make shipping a bit interesting, but I think you'll get much better performance from a weld.

 

[hokie66]

15 kN-m, but in what direction? Parallel or perpendicular to the supporting member? The girt at top would suggest perpendicular, in which case the connection doesn't do much.

 

[r13]

Check the strength of the clip angle for bolt bearing and the uplift.

 

[Veer007]

I don't get moment direction so far, but for a post, I would strongly recommend which is perpendicular to C100 running direction at the top. which can satisfy the moment?

Thanks in advance!!

 

[Veer007]

It's not clear what you are asking. I don't see a moment force shown?

Just below on HSS, 15kN.m

Thanks in advance!!

 

[r13]

This connection has zero construction tolerance, the end result will be either too loose, or the post won't fit in. It does not have moment capacity for rotation about longitudinal axis of the beam. Consider phamEng's suggestion seriously.

 

[Veer007]

This is not slip critical connection, bolts to be bearing type.


I would propose this

Thanks in advance!!

 

[EngineeringEric]

The connection, nor system, likely dont work. you may be better with a fixed end moment plate on the HSS, bolted to the W-section, then you have to brace the W because i am betting it cannot handle the torsion

 

[phamENG]

This is not slip critical connection, bolts to be bearing type.

If this is in the middle of the roof (a screen for mechanical unit, perhaps?) and not a parapet, this could easily result in a roof leak. you'll get movement in the connection before the bolt bearing is engaged and the continued movement will probably, over time, damage the pitch pocket or whatever the architect as specified to waterproof the roofing penetration.

Eric - looks like the roof beam below is a HSS254x152x9.5 (HSS10x6x3/8), not a wide flange. Along the same idea, though, you could go for a saddle type connection. A fabricated U shaped plate that slips over the 6" dimension on the HSS that has the post shop welded to it. Then you can blind bolt the saddle to the HSS beam. The blind bolt won't crush the HSS, and has the advantage of pulling the plies into contact.