C-Shaped Wall with Fiber Section

[joseacs]

Hi everyone,

I want to model a C-Shaped wall using 3 displacement-based B-C elements (1 for web and 2 for flanges). Thus, the entire section of the wall is conformed by 3 rectangular sections. I have some questions about this:

1.- At the corner of the wall (intersection of web and flange), is there a problem if the flange fibers are overlapped with those of the web?
2.- The flanges section is not symmetric, because there are more rebar at the edge far from the web. So, the section centroid is not in the middle. However, I have defined the nodes in OpenSees in the middle of the flange length. Should I draw it in the centroid of the flange section? Or that does not matter?
3.- In gravity analysis, I have defined a load in the node of the top of wall, this load is applied in the section centroid or the (0,0)?

As additional info, the (0,0) of the fiber sections are defined in the middle of each section.

Thank you very much!