You can also specify a diagonal grid system in Etabs by basically doing exactly what you would normally do in creating a rectangular grid system.
Simply go to edit grid system, create a new grid system (you can call it diagonal for ease of reference) then in the Edit Grid tab click on the...
I have found the following link to be useful in determining both the type of diaphragm and hence the distribution of shear forces to the various lateral load resisting elements.
http://urban.arch.virginia.edu/~km6e/arch721/content/content.html
Hope this helps
Ryan.
Under what conditions are couplers required in lateral elements to resist lateral loading (wind loads)?
My understanding is that lateral loading induces flexural tension into the core (lateral resisting element in this case) and hence as this is not defined as direct tension in AS3600 (i...