Need connectiona dvice: I beam to vertical hollow section 1

[kingnero]

See attached sketch:

I need to attach a horizontal I-beam (point load in the middle = 2000 N, length = 4 m) to two vertical members with a hollow section of 120/40/3 mm.

This is a home project, and I'm using what I have lying around, so I'd prefer using these hollow sections but if what I suggest in the attached sketch isn't really feasible, please feel free to advise.

The setup is symmetric, and the vertical members will be attached to both walls (the walls are made of lightweight bricks, so I can't put fasteners in 'em to hold up the horizontal beam).

I don't know how bolted connections are designed for this type of combination, so don't shoot me if I'm thinking totally wrong about this one...

as for the drilled and tapped holes, I'd drill the plates first (all four in one stack), have two of 'em welded on the vertical members, drill through the 3mm of wall thickness, and thread them. in that order. + drill again with a bigger drill for the clearance holes, and have them welded on the I beam.

your opinions on this connection please?

 

[dik]

2000N = 2 kN = 500 lbs+/-... not much of a load. Reaction from the beam weight is likely comparable...

Use a 3/8" plate welded to the face of the HSS... of can you rest the beam on the HSS and bolt...

Dik

 

[kingnero]

Indeed, the load is rather small, own weight of the beam is almost negligible (8.5 kg/m)(I did take that into the 2 KN load).

but I don't understand your following comment: (HSS = hollow structural section, right?)
See attached sketch, that's what you mean?
If so, how to fasten the angle iron to the vertical members? Bolting or welding?

thanks in advance...

 

[dik]

If you can shorten the HSS (yes) and weld a cap/crown plate to the tube and sit the beam on top and bolt the beam in place it would be a better detail. The thin tube is quite flexible in the direction shown.

For 1/8" tube, you can use a 1/8" fillet weld for connection or possibly 3/16 (4mm). Some codes do not recommend using a weld greater than the thickness... CIDET research indicates that goint 15% or so greater provides weld capacities similar to full penetration welds.

With the small loads, welding should not be an issue.

Dik

 

[kingnero]

OK. thanks for that, I appreciate your opinion.
I'll do it that way (another sketch...).

One last question: cap plate thickness = ?
3mm (1/8") will be too thin I guess?
Would 1/4" be good?

 

[ukengineer58]

you could. use hollow bolts. instead of welding. do a Google search

 

[dik]

I typically use 3/8 as a minimum conn plate thickness...

Dik

 

[rb1957]

so you're welding a plate to the top of the column, and picking up the I-beam with two bolts away from the NA of the column ?

i'd rather see the attachment to the column being symmetric around the column NA.

you could weld an angle to provide a step for the I-beam to sit on.

 

[dik]

The beam should be bearing on the column...

Dik

 

[kingnero]

@ rb1957: I beam is only 55mm wide, the HSS is 120 mm wide.
Unless I'll find hollo-bolts here, I can't really fasten the beam on the capplate.
As I only need 4 of those bolts, I doubt I'll find small quantities for sale.

@ ukengineer58: thanks for the tip, I didn't know they existed. It's good to know.

@ dik: thanks again.

 

[rb1957]

so the I-beam can't sit on top of the column ? (it has to be placed to the side of the column.)

if the I-beam can't sit on top of the column, can you weld a bracket to the column that'll provide a rest for the I-beam ?

if the I-beam can sit on top of the column, why can't you bolt symmetrically about the column ? (your pic shows fasteners only on one side of the column, why not both sides ?)

if the I-beam flange is wide enough, why not just weld it to the column ? if it isn't, why not weld a plate to the I-beam flange to make it wide enough ?

 

[kingnero]

so the I-beam can't sit on top of the column ? (it has to be placed to the side of the column.)
I-beam will sit on top of the vertical HSS (which will have a cap plate welded on top of it).
All the way until it's also against the wall (see explanation in first post).


if the I-beam can sit on top of the column, why can't you bolt symmetrically about the column ? (your pic shows fasteners only on one side of the column, why not both sides ?)
because the HSS will be bolted against a wall, I only have access at the "open" side.

 

[rb1957]

if the column is bolted to wall, why not the beam as well ? that'd help balance the load on the plate.

why not weld the beam directly onto the column ? yes, i know the beam is narrower, so weld a plate on the beam's lower flange. the idea should be to get the most direct loadpath from the beam to the column, yes?

the two bolts into the plate, offset from the column, look really (IMHO) ugly. could you tap the holes in the plate and so bolt within the hollow column ? you could add a couple holes to the plate and weld a couple of bolts so their threads protrude.

there are many ways to skin this cat, but IMHO the 2nd pic (of the plate) is possibly the most torturous.

 

[kingnero]

if the column is bolted to wall, why not the beam as well ?
see first post. the HSS transfers the load to the foundation.

why not weld the beam directly onto the column ?
Needs to be bolted for erection reasons. Can't weld in situ. Can't place the welded construction in one piece.

the two bolts into the plate, offset from the column, look really (IMHO) ugly.
appearance is not important. the design (and safety and such) of course is.

could you tap the holes in the plate and so bolt within the hollow column ?
I could do that, but that means a 1/2 inch or thicker plate has to be welded to a 1/8 thickness HSS.
Which is also not an ideal solution.

there are many ways to skin this cat
I would gratefully receive a better solution.

the 2nd pic (of the plate) is possibly the most torturous
2nd attachment has an angle iron, third has a cap plate drawn ?

 

[CANPRO]

Small loads and short spans...I'd do this in timber unless you have a practical reason for using steel.

 

[rb1957]

my apologies, i missed the 2nd pic, supporting the beam witha an angle welded to the column. this seems to me to be the neatest connection.

 

[kingnero]

2nd and 3rd pic are the same principle: the beam rests on the HSS,
with the cap plate it spreads the load a bit more.
Both their primary purpose is to fasten the bolt in position. The bolting does not serve to act as a load path.

@ CANEIT: Cannot do. I don't know the translation, but see attachment.