Perforated Roof Diaphragm
Perforated Roof Diaphragm
(OP)
I've got a one story commercial structure (metal deck, bar joists, steel girders), and the roof is essentially perforated with sky lights all over the place. How many penetrations (maybe as a percent of the overall roof area?) are allowed before you have to reevaluate the diaphragm strength? Or can you make the frame around the openings rigid enough to transfer the diaphragm forces?






RE: Perforated Roof Diaphragm
Hence it may turn cozier directly analyze with membrane or so elements and see what is happening.
RE: Perforated Roof Diaphragm
On the stiffness/deflection side you can break down the diaphragm into individual pieces and add together their individual portion of stiffness to get a somewhat accurate prediction of diaphragm deflection.
So lots of openings do reduce the shear capacity and stiffness, its just the means to calculate it all that get a little tricky.
RE: Perforated Roof Diaphragm