Shear flow in cracked reinforced concrete composite section 1

[StrM]

Hi
I need help in calculating shear flow at interference of flange and web of T section. both web and flange are reinforced concrete sections, web is in compression and flange is in tension. concrete is assumed to be cracked.(need to use Icr instead of Ig). not sure what to take as Q since concrete is cracked in web itself above the interference where I need to calculate shear flow.
I am trying to calculate dowels required in order to keep web and flange fully composite.

If it helps here are the specification:
tw=36"
dw=14"
tf=48"
df=7"
Layer of steel = 8-#6 @12.25 from top of web and 3-#4 at 17.5" from top of web.

Thanks

 

[GC_Hopi]

Here is a good explanation with examples. Link

 

[KootK]

It's worth noting that your situation is actually a plastic design shear flow problem rather than the usual VQ/It elastic design business. Sometimes the elastic analysis can be used conservatively for the plastic situation but it's best, I think, to really understand the differences before diving in. This recent thread discusses this topic at length: Link. Also, see steveh49's post for what I consider to be an excellent method for handling this exact problem.

 

[r13]

I don't quite understand the reason for calculating shear flow on a concrete T beam, if the flange and the web are cast integrally. If the flange and the web are cast separately, then you shall perform the calculation the usual way, on the full cross section without reinforcement, to determine the shear stress at the interface, and design the connectors required for composite action.