JCFmat model - UCS Prediction - How "intRadius" affect the models?

Dear All,

I am currently facing a significant challenge while conducting UCS tests using the JCFmat model. The issue revolves around the parameter "intRadius," and I would appreciate your insights into its impact on the models.

The problem arises when I set "intRadius" to 1.5. At this value, the UCS measures approximately 20 MPa. However, when I increase "intRadius" to 2.0, the UCS drastically jumps to around 200 MPa.

In the second trial, the stress-strain curve deviates from the typical curve observed in our other tests. It initially exhibits an elastic stage up to 50 MPa, followed by a small peak, and then transitions into another elastic stage with a lower slope until it reaches the peak at 200 MPa. I suspect that the issue lies with the "intRadius" parameter. Does anyone have insights into what might be causing this?

For reference, I am using the approach outlined in the paper available at https://hal.science/hal-01315522/. It would be immensely helpful if someone could provide a code snippet used in this paper for simulating the UCS test.

Thank you for your assistance.

Best regards,
Mahdi