calculate if glulam beam to I-beam

[Granngubben]

I perceive it as a beam with a 5 m span that needs to carry a load of 121 kN, (41 kN point load in the middle, the remaining evenly distributed).

Structurally, a beam in steel S355 of approximate dimension HEB180 or VKR220x120x10 is required.

The deflection for these steel beams is likely close to your glulam beam 90x450, (depending on the glulam quality).

Each support should bear just over 60 kN. They would be steel columns, right?

 

[Fredrik Olofsson]

Initially, there are two openings in the load-bearing wall with a pillar/wall stump in the middle. 41 kN is the total load on the pillar/wall stump in the middle. Then there is a kertobalk on each side. Half of the load from the beam goes to the pillar/wall stump from each side. Line load 16kN/m. House module width 2.55m (Älvsbyhus). 2x2.55/2 x 16 = 40.8 = 41 kN.

And then the pillars at each outer end should bear the same amount (41 kN) if I interpret the calculation correctly, or am I wrong?

 

[Locke]

So it's not a point load in the middle but a support?

With 41k N on a total of three supports, the total load becomes 123 kN. A span of five meters and 16 kN distributed load, however, only gives 80 kN.

I can't quite make sense of it. Do you perhaps have a sketch to share?

 

[Fredrik Olofsson]

I have a drawing of how it looks from the beginning at each opening. How do you attach a PDF?

 

[Granngubben]

Do you mean that two Kertobalks, (L = 2.55 m), each carrying 41 kN should be replaced with a simply supported beam with a span of 5.1 m and a distributed load of 82 kN?
The column/wall stub is removed?
No point load?

 

[Fredrik Olofsson]

Yes, there are two kertobalkar beams supported by a pillar at each end. They meet on each side of the module joint in the house and are constructed together as a wall stub. If I calculate with a line load of 16kN per meter, I get 2.55*16=20.4kN (the house modules are 2.55m wide) on each pillar. And since in this case there are four pillars bearing 20.4kN each, it becomes approximately 41kN that the beam will carry in the middle if you remove the wall stub. And then, of course, the pressure increases on the two new pillars that are supposed to bear a 5m span, and it should then be double what it is today, or am I wrong?

 

[Granngubben]

I have a drawing of what it looks like from the beginning at each opening. How do you attach a PDF?

Click on "extended reply box", browse to the file, upload it.

Where does 16 kN/m come from?

 

[Fredrik Olofsson]

16kN comes from the manufacturer of the house.

Attached is a drawing of what an opening with a relieving kertobalk looks like. There are two such side by side that are joined in the middle, forming a wall stub in the middle.

 

[Granngubben]

Did I get it right?
1. The house manufacturer says that the Kertobalkarna beams are dimensioned for 16 kN/m.
2. You want to remove the wall stub and have a steel beam with a span of 5.1 m instead of the two Kertobalkarna beams.

I calculate that the new beam should carry 16x5.1 = 82 kN, distributed load.

 

[Fredrik Olofsson]

1. Yes
2. Exactly

and as point 3, each pillar according to the drawing carries, if I calculate correctly, 20.4kN because they take half the load each at a 2.55m span.

 

[Granngubben]

Several questions:
You wrote that you made a calculation for a glulam beam 90x450, do you still have it?
What deflection did the calculation give?
Does it recommend a max deflection of L/400?
What column load did the calculation give?

Just asking to reduce the risk of misunderstandings.

 

[Fredrik Olofsson]

That is precisely the problem. That calculation is no longer valid today. Apparently, a beam of 115*450 is required today. According to the previous standards, I could use a beam that was only 90mm wide. If a guide value for a glulam beam is needed according to the new standards, using Moelven's beam stock program, it provides a deflection of 12mm and L/426 on a beam that is 115*450mm. The calculated sizing of the column load is 46.7kN.

 

[Granngubben]

Possible beam dimensions are:

IPE270, the lightest, narrowest, tallest
HEA220, the widest
HEB200, the heaviest, lowest

All three are wider than 90 mm. If you absolutely want a beam that is maximum 90 mm wide, you need to go to the blacksmith and ask him/her to weld a beam with flanges 90x20 and a beam height of 260 mm, preferably a box beam with double web plates to avoid the risk of buckling.

 

[Locke]

That will be a proper beam! Also consider how you transfer the loads to the ground. Then there's the matter of fixed-end supports which might be interesting to consider.

Neighbor guy: Can't you do the equivalent calculation you did for the other beam guy?

It's really a shame to place it freely.

 

[Fredrik Olofsson]

That will be a solid beam! Consider how you will transfer the loads to the ground as well. Then there's the matter of fixed-end supports that could be interesting to think about.

Granngubben: Can't you do the equivalent calculation you did for the other beam guy?

It's really a shame to simply lay it down freely.

What do you mean by fixed-end supports? Why is it a shame to lay it down freely? Now I'm not following...