Johnson-Cook damage model ?

[Nir_k]

Hi, everyone. I want to ask a question about the JC damage model that has been bothering me for a while now, and I feel that it might turn my previous knowledge upside down. Is the strain value calculated by the Johnson-Cook damage model used in Abaqus software the fracture strain? Or is it the damage initiation point strain?
I found some articles that indicated that the strain calculated by the Johnson-Cook damage model was the equivalent plastic strain at the point of damage initiation. In contrast, others indicated that the equivalent plastic strain at fracture was calculated!
I'm really confused. Can you help with this? Thanks a million!

 

[FEA way]

It’s equivalent plastic strain at failure. Check the documentation chapter Materials —> Inelastic Mechanical Properties —> Metal Plasticity —> Johnson-Cook Plasticity (paragraph "Johnson-Cook Dynamic Failure").

 

[Nir_k]

FEA way, Thank you for your answer, but what is the definition of "failure"? Is it "Damage initiation" and later, or is it the final "Fracture"?

 

[FEA way]

This damage model (*SHEAR FAILURE) doesn’t distinguish between damage initiation and evolution, it’s just failure (and element deletion by default). However, there’s also progressive damage and failure model for the JC plasticity.