Recent content by staffengw

I think I found my problem. I was choosing a value of a, then getting the values of c, the compression area (Acomp), the distance to the compression area centroid (y'), the stress in the steel (fs = (0.003/c)*(d-c)), then the phi factor (relating to the c / d ratio), then phi*Pn =...

I did not consider both bars for the diagram. I neglected the bar when it was on the compression side since there are no ties.

I used f'c = 5000 psi, the full 24" width as effective, and 2) #4 bars. Attached is a sketch to clarify further.http://files.engineering.com/getfile.aspx?folder=d377cb77-dba2-4cd2-88e7-7461297692d9&file=Section.pdf

I have been trying to come up with an interaction diagram for a wall section with a 24" wide, 2" thick outside face with a rib that projects out from the face 4.875" and is 3.5" wide. I usually do interaction diagrams for rectangular sections and am really concerned that I am getting wrong...