Transferring diapragm shear forces

[PowersPE80]

Can diaphragm shear forces be transferred from WF beams to slab (on metal deck) diaphragms, and vice versa, within the same diaphragm?

Here is my situation:
I have (2) diaphragms that are interrupted by a slab opening. The girders run through the opening but they are unbraced (not attached to any slab) at the opening. Can lateral force from one diaphragm be be transferred to a collector beam, "carried" through the opening, and transferred back into the diaphragm on the other side of the opening, and eventually to the braced frames?

 

[JAE]

Based on your description I'd say yes you can transfer shear that way - just chase down the load path and make sure that everything along that path can take the loading.

A sketch of your problem might be helpful to clarify what you have.

 

[PowersPE80]

Thanks. I have followed the load path. On a related question, do the composite shear studs give my diaphragm additional capacity? I have been designing the diaphragms based on the allowable shear values in the deck catalogs. These allowable values are based on deck size and attachment of deck to the structure, but there is no mention of shear studs.

 

[KootK]

I think that the composite studs would increase your capacity in the sense that they would serve as an improved version of the flute fasteners (welds / pins). Two potential problems arise:

1) You may already be using your studs for ordinary flexure. If so, you'll need to make sure that you're not double dipping when it comes to capacity.
2) Even with composite studs in the field, you're probably counting on shear transfer at some deck edge (angle etc.) where the transfer is through your deck fasteners only. This would limit your usable capacity.

For these reasons, I usually stick to the non-composite stud capacity unless I'm trying to do something special.