Stiffener Spacing

[ToadJones]

I am analyzing girders that have web stiffeners staggered on opposite sides of the girder. On each side the space is 7'-0 but they are staggered 3'-6".
What would you consider the spacing to be?
7'-0?
3'-6?
somewhere in between?

 

[SAIL3]

I would use 3'-6...assuming the stiffeners were designed as single stiffeners.

 

[a2mfk]

I think it depends on the loading and how that relates to the stiffener locations. These are stiffeners for flange bracing due to point loads?

 

[JAE]

For resistance to web buckling or crippling, I'd go with the 3'-6" per SAIL3...assuming that the stiffeners meet the design specification.

 

[ToadJones]

JAE-
The spec is AISC.
Problem is, I am using AIST 13 for mill buildings, which basically requires that the stiffeners are used in pairs.
You say "For resistance to web buckling or crippling" and I guess they are. I am assuming they are there for shear capacity.

 

[ToadJones]

JAE-
Excuse my ignorance....I have honestly never designed a single stiffener. I just looked in the Spec and found the design for single stiffeners.
I'll check if the stiffeners meet the single stiffener requirement.

 

[csd72]

RE:'You say "For resistance to web buckling or crippling" and I guess they are. I am assuming they are there for shear capacity.'

For a plate girder these pretty much amount to the same thing, the only difference is the source of the loads.

 

[ToadJones]

CSD...after re-reading that, I don't even know what I was thinking when I typed it.