hHi Pablo

you try doing the following

1- creat solid model for concrete

2- creat solid cylinder as it will be subtracted from concret to make hole

3- creat solid cylinder to be a steel bar

4- assymble the steel solid cylinder inside the hole

5- use connector type translator to model load slip curve between inside surface of whole and outside surface of steel cylinder bar

let me know your progress

regards

How would you validate the results?

Please see:

Bond slip model for the simulation of reinforced concrete structures

A.Casanova, L.Jason and L.Davenne