It highly depends what you are after ...saso wrote:Funny thing, I was just today thinking (wondering) how the reinforced concrete FEM calculations work (the logic/methods behind it)

first:

If you are in an structural engineering office designing reinforced concrete structures every day. A face mesh of the whole concrete building is taken and calculated by FEM. No reinforcement and no cracks are considered in the FEM analysis. The reinforment is calculated afterwards with the results of the FEM analysis.

second:

If you are at university and like to calculate what you have (or would like to) test or really destroy in an fracture test. Mostly simple geometry like a loaded beam. You would make a solid mesh off the beam including the reinforcement. Contact between reinforcement and concrete as well as cracks in concret should be considered in the analysis.