Yes, I will check it out. But the rib patter doesn't go all around the rebar, it is stop start. nI tried running the model with contact sizing of 5mm and face sizing of 2mm but I get an error (An unknown error occurred during solution. Check the Solver Output on the Solution Information object for possible causes) at this stage:nWould you know why this is the case? The force in the experiment is applying the force incrementally until the stress in the rebar reaches 500MPa over a 2 minute period and holding this load for a further of 2 minutes. So, since I am only modelling half the model due to symmetry, I have created 240 steps, which the force incrementally going up every step to around 28kN and then holding it there for another 120 steps. nWhat would you recommend to fix this issue/are there any other alternatives? I am just trying to see what is the slip between the rebar and concrete during the loading I described before. nThanks again for your help and time! n