Wood Diaphram Shape

[TimmyH76]

We have a fairly long narrow diaphram. The shear loads are going to be a problem at the ends of the diaphram. Has anyone ever designed a diaphram so that the ends are "flared" so that the shear per foot is less than if the diaphram was a rectangle.

 

[msquared48]

I suppose that you could angle the edges of the roof framing by the opening at the exterior walls to increase the length, but that would really screw up the framing layout.

Are you sure there are no other interior shearwall locations you could drag the forces to, breaking up the size of the diaphragm into smaller pieces?

Mike McCann
McCann Engineering

 

[csd72]

TimmyH76,

Can you explain the situation a bit more so that we can give you a more informed answer.

 

[111213]

hi,
are the long sides free edges ? what about the opening ?
in general, flared edges have in this case an very little
effect because the main trajectories of the moments are not changed, they dont spread !