Hi Alejandro,

What you obtained experimentally is likely engineering stress versus engineering strain curve. You should convert it to true stress versus true plastic strain before providing it to the model.

Please note that your resulting hardening curve should only be increasing with plastic strain, i.e., if your experimental data is noisy, an error message may appear when you solve the model. In such a case, it might be a good practice to fit a mathematical function (such as power-law or Voce functions) to your data so that it becomes smooth with true stress only increasing by plastic strain.