If you run the numbers, in one direction the plywood
diaphragm does in fact calculate out to be rigid.
In the other direction, it calc's out as flexible.
This is another thing engineers have never had to
deal with before, a diaphragm flexible in one
direction, rigid in the other.
Answer me this, if the diaphragm is rigid, then it
will distribute loads by rotation to walls
perpendicular to the forces if the center of gravity
and center of rotation are not coincidental.
However, the as in the other direction the diaphragm
is flexible, it is not not capable of transmitting
the loads by rotation. The design theory breaks
down at this point.
How in the world to you figure this one? One can or
worms after another!!