I am looked through the 14th edition of the AISC steel manual and see that there are two options for rectangle section moduli in Table 17-27. One is moment about the middle neutral axis and is typical but I also see this one, S = bd^2/3, for moment about the edge of a rectangle. What real world...
I am working in the US with the 2018 NDS and would like to know how what equations are needed to find what the NDS Commentary in 3.5.2 calls long term and short term deflections in wood columns?