Ductile Failure using Gurson model Abaqus: Implicit and Explicit

Hi all

I am using Gurson model embedded in Abaqus. I almost simulate the softening part using implicit. however when I tried to simulate the elements removal to simulate the last sudden drop on load, I have to go for explicit.

The problem that the explicit takes long time.

And the main issue that the hardening part has been changed and the model could not catch the maximum load and fail too early.

The image down show the problem ( red:experiment, Blue:implicit, yellow:explicit).

Could anyone tell me why this happen?

Additionally, the total energy increased during the explicit.

Thank you.