The response of Abaqus is a little different from the model

[ptignol]

Hello,

I wonder why, when I enter the comportement of concrete in the "concrete smearded cracking", and when I make a simulation of compression, the response given by Abaqus doesn't supperpose to the initial law.
It doesn't differ by incremental step, and when I use a result as a model, the second result is also a bit different.

Do someone know why?

thanks