roof diaphragm

huangyhg

roof diaphragm
i am fresh graduate and i am looking for simple explanation of "roof diaphragm".
thanks
kris
check out our whitepaper library.
horizontal plane that transfer the lateral forces (induced by wind or seismic) to the vertical lateral resisting system (shear walls, braced frames, etc)
think of it as a deep beam laid sideways.
the vulcraft steel deck catalog has a simple roof diaphragm design example and is available free online.  beyer's "design of wood structures" also explains diaphragm action for wood.  simpson strong-tie has some basic explanations as does the apa.
ucfse,
excellent source. i would have recommended the same. you have my thanks for valuable post.
regards,
lutfi
here's simple: think of when you are using a deck of cards to build a "house"  the cards on the sides won't really stay up by themselves until you lay card over them: the top cards would be the "diaphragm".  
roof diaphragms typically consists of sheets of plywood over the roof rafters tied into the bearing walls.
with that in mind, check out some of the references recommended above.  hope this helps!
other terms to look for in the diaphragm concept is drag members and chord members.  drag members are elements along a line of lateral resistance which collect and deliver the diaphragm forces into the lateral force resisting elements.  chord members are perpendicular to the drag   
i am interested in obtaining information concerning the design of and retrofitting of existing roof beams to handle roof anchors, forces, etc. associated with fall arrest systems.  does anyone know of a book or technical paper that might provide this information?  thanks
any references on designing diaphragms for a hip roof?