Direct torsion is taken care of, but "accidental torsion" is not. Both wind and seismic have accidental torsion in them per the new codes. These have to be modeled as a separate load case.
In the case of wind, you just apply the torsional load cases. In the case of seismic, you have to hand...
I just put a message in the 'wood/residential' thread that pertains to this. (See it for more info.)
While I was addressing wood in particular, any flexible diaphragm with fasterner slip (plywood, or steel deck), has the same requirements for getting an accurate model.
As soon as you get...
A quick word of caution in case you were thinking about using plate elements for modeling wood shear walls (say, for force transfer). Without a lot of care, you can get grossly inaccurate results.
1) you MUST model for the shear stiffness "G", rather than "E". (You cannot model for both. The...
If you go the the strap bracing option, be sure to check seismic. Because of the extremely low R value for the system, and the additional requirement that tension-only bracing has to be designed with the Omega multiplier, you will find that seismic will often control for the strap bracing even...
Shear transfer is handled by the moment couple in the two nails used to attach the skip sheathing boards to the rafters.
It isn't a very big moment capacity per connection, but there are a lot of them, and it adds up. AITC has an example calculation in their Handbook.
It's a perfectly fine method. As mentioned above, IBC covers gyp, plywood/osb, and gauge metal steel panels. Be sure to read the text. The table is full nominal strength before factor of safety reduction. The seismic R value for such systems limits you to 4 stories.
There is also a listed (ER...
