Questions and discussion for this lecture live here. Fire away by hitting Reply below 
Hi Sean, I have a question about your D_s notation. Why D_s with a line above the D? You then said the reason for it is the notational consistency, but I haven’t seen you place a line above \epsilon_s or \sigma_s.
The D_s (with the overbar) simply denotes the base shear constitute matrix - i.e. G x the 2x2 identity matrix. There is no special significance to the overbar - I guess you could drop it, especially since the equivalent bending matrix doesn’t have an overbar. We don’t actually apply an overbar decorator to any other quantity.
One thing to be aware of is that the decorators don’t necessarily mean the same thing when applied to different quantities - for example, sigma_hat (carrot or hat symbol on top) denotes stress resultants whereas epsilon_hat denotes generalised strains.
Just something to be aware of.
S
1 Like