Converting code from version 5.2 to version 7

Dear colleagues,

I have written a code in 3DEC version 5.2 for simulating fallout at deep underground mines. The code ran correctly on this version, and I then converted it to 3DEC version 7 using the same parameters. However, while the code on version 5.2 reached equilibrium after one day, the version 7 code did not after 1 week.
I assigned high-strength joint parameters before excavation for both models. once it reaches equilibrium, I will change the joint parameters to their real values before excavation. For ‘block contact material-table default prop’, I assigned real joint parameters or low-strength parameters for discontinuities.
I would appreciate any assistance in understanding why the version 7 code did not reach equilibrium.

Based on that small amount of information it is hard to guess what the problem might be. If you can share your data publicly, then please add more information. If it is more sensitive data, then send it to Itasca for inspection.

Some usual suspects:

  • some property names have changed, which maybe the autoconvert made a mistake on
  • same with boundary conditions, stress initialization etc.

It’s hard to tell for sure without the whole data file, but it looks like you have an initial stress state with some non-zero shear stresses. Since all of the boundaries are stress boundaries, it is possible (likely) that the whole block will rotate. If you have shear stresses, you probably want to fix at least one boundary to prevent this.

I would send the data file to technical support if this doesn’t solve it.