Replace glulam with steel beam?

[Panelmannen]

I'm working on the planning of a possible carport with the opening on the long side (6.5x10m).

The designer of the roof trusses has drawn a massive glulam beam measuring 6.8 m long and 115x630.

My question now is what steel beam I can replace this with? I have support reactions (to the right in the picture).

 

[justusandersson]

You can use a glulam beam with dimensions 215x495 instead. The equivalent among steel is either HEA 260 or IPE 300.

 

[Panelmannen]

You can use a glulam beam with dimensions 215x495 instead. The equivalent in steel is either HEA 260 or IPE 300.

Thank you very much! Do you know where I can find that info?

 

[justusandersson]

It was something I figured out. You need to know a bit of basic mechanics of materials to do it. You can't easily read up on it.

 

[Panelmannen]

Just out of personal interest, which column are you using for the calculation? i.e., is it LK P, LK M, or LK K that is the dimensioned one? I studied structural engineering in the early '90s but don't remember everything..
I need to dimension a pillar for the right support as well.

 

[justusandersson]

I just did a recalculation based on the glulam dimension you were informed about, i.e., 115x630. To find other glulam dimensions, I compare the moment of inertia, calculated according to the formula I = (b*h*h*h)/12. To compare with steel dimensions, I compare the bending stiffness, i.e., the product of the modulus of elasticity and the moment of inertia. Then I look in a steel table to see which dimensions have the correct moment of inertia.