Load-bearing capacity of aluminum L-beam

[Violina]

Pure "bending stiffness per kilo" is probably best with IPE. There are several alternatives. If we now "agree" on which moment of inertia is required, it is easy to check tables.

But.. I still vote for prebending.. and then it's easiest with pipes

 

[Erik Lindroos]

I would have placed a rod at the far end and one in the middle, letting one long side be supported by the edge (as it is now)

So each rod only needs to hold "just" 1/3 of the deck's weight..

Hence my lighter dimensioning..

More reflection: the middle beam would then have to take more than a third (closer to half?) of a distributed load, and the outer beams less. Or? Am I thinking crooked? Probably depends on the cross beams.

 

[Derbyboy]

What a damn project it will be (both expensive and cumbersome) if the original poster insists that the entire roof should be able to retract under the terrace with a span of over 8 meters. I'll be insanely impressed if you, the original poster, manage to finish it.

At this point, I would probably have bought a pool cover or filled in the pool and grown potatoes.

 

[Erik Lindroos]

Sure.. I'm still voting for pre-bending.. and then it's easiest with tubes

Absolutely, I think it would be cool, but is it worth the trouble if you can keep the deflection under 15 mm without it? I have no idea how complicated it is...

 

[Violina]

More reflection: the middle beam should then take more than a third (closer to half?) of a distributed load, and the outer beams less. Or? Am I thinking incorrectly? It probably depends on the cross beams.

Now I'm getting puzzled myself

But I would think that since the other long side always has support, the most sensitive point is the long side that is free..

If it only had support under the short sides, then the middle would probably be "most exposed," but now one long side has support.. so if you throw in nog between the long sides, a lot of the load is taken up by it..

 

[Violina]

Absolutely, I think it would be cool, but is it worth the trouble if you can keep the bending under 15 mm without it? I have no idea how complicated it is...

It's super easy...

Just heat a few points on the radius of the pipe with the gas

 

[Erik Lindroos]

Shares the previous post's view that one might not consider snow load…

In the examples I've calculated, it seems that you get immunity to snow load as a bonus. The requirement for a maximum deflection of 15 mm is so tough that the beams can withstand a lot of load.

 

[Violina]

In the examples I've calculated, it seems that you get immunity to snow load for free. The requirement of a maximum deflection of 15 mm is so tough that the beams can withstand a lot of load.

But it also becomes quite heavy...

Right?

Edit: And in my world, 15 mm deflection is A LOT

I usually design with a maximum of 1 mm per meter span

 

[Erik Lindroos]

Now I'm getting confused myself

But I would think that since the other long side always has support, the most sensitive point is the free long side...

If it only had support under the short sides, then the middle would probably be "most exposed," but now one long side does have support... So, if you put nog cross braces between the long sides, quite a bit of the load is probably taken up by that..

I think the extremes are between a) a super rigid floor that distributes the load equally -> 1/3, and b) a "flimsy" floor (like a tarpaulin) that puts half in the middle and a quarter on each side.

But certainly, you should make use of the support on one side and not waste a large beam there.

 

[Huggedugge1]

In the examples I calculated, it seems that you get immunity to snow load as a bonus. The requirement for max deflection of 15 mm is so tough that the beams can withstand a lot of load.

Thank you so much for your calculation!!! That sounds good! I checked VKR on Montano.se. They didn't have that exact dimension, but from what I understand, a 12m beam should cost around 20ksek.

Then I'm unsure about how many beams you think I need?

 

[Violina]

I think the extremes lie between a) a super stiff floor that distributes the load equally -> 1/3, and b) a "flimsy" floor (like a tarp) that puts half in the middle and a quarter on each side.

But sure, you should utilize the support on one side and not waste a huge beam there.

No.. I mean.. no pipes there.. just wood..

 

[Violina]

Thank you so much for your calculation!!! That sounds good! I checked VKR at Montano.se. They didn't have that exact dimension, but from what I understand, a 12m beam should cost around 20ksek.

Then I'm unsure about how many beams you think I need? [image]

You need two.

One on the free long side and one in the middle.

 

[Huggedugge1]

How do you attach them in printed 195*45?

 

[Violina]

Then you can buy pre-cut from many suppliers...

Since you need two, you might be able to get it from something like Tibnor or BE Group or a similar supplier.

 

[Violina]

How do you attach them to pressed 195*45?

I would drill them and the wood, then use screws and nuts with a large washer on the side that's in the wood.