From: Roger Turk <73527.1356(--nospam--at)compuserve.com>
Date: Fri, 7 May 1999 12:10:17 -0400
These comments are based only on a visualization approach.
It seems to me that the definition of what constitutes a rigid and flexible
diaphragm is reversed. It seems to me that a flexible diaphragm would be one
whose "... maximum lateral deflection is *less* than ?? times the average
story drift ... ." (Actually, why is it even related to story drift?)
This is because the diaphragm does not even start to behave as a rigid
element *until* the sheathing panels come in contact with each other. Since
the panels are/should be installed with 1/8 inch spacing between them, a lot
of movement can occur before the diaphragm starts to act as a rigid diaphragm.
A. Roger Turk, P.E.(Structural)