Reply To: Most simple material model for non-linear plastic in LS-Dyna Mechanical WB

[Armin]

No problem Douk.
You are correct. You need to convert your engineering stress-strain data into true stress - plastic strain and then input it into the model. Check the paper below and the references therein where this topic is discussed in more detail. The end of the linear region is typically determined using the 0.2% offset rule (you can look up 0.2% offset rule online and you'll be able to find relevant information).

https://www.sciencedirect.com/science/article/pii/S2666359722000208