How to use restart

General Questions
1

I found a way to restart in this post. I can reproduce the operation using the calculix interface, but I cannot implement it using the prepomax interface. Can someone guide me?

How to use *restart? - CalculiX (official versions are on www.calculix.de, the official GitHub repository is at https://github.com/Dhondtguido/CalculiX).

  1. Prepare 2 set of data files and name them as ex. step_1.inp and step_2.inp

  2. Copy step_1.inp to step.inp
    “step_1.inp” holds the original geometri & load for 1’st run

  3. Run ccx -i step

  4. Copy step.frd to step_1.frd
    “step.frd” holds output specified in the cards “*node file” & “*element file” for 1’st step

  5. Copy step.rout to step.rin
    “step.rout” holds the stiffness matrice, strains & deformed geometri from first run

  6. Copy step_2.inp to step.inp
    “step_2.inp” holds load for 2’nd run expected to be added to 1’st result

  7. Run ccx -i step

  8. Copy step.frd to step_2.frd
    “step.frd” holds output specified in the cards “*node file” & “*element file” for 2’nd step

Result from step 1 will be in step_1,frd and step2 in step_2.frd

2

Restart is currently not supported in PrePoMax GUI. You can add its keywords using the Keyword Editor but it also requires renaming files. Isn’t it easier to prepare the .inp files with PrePoMax, submit them using standalone CalculiX and postprocess in PrePoMax ? It’s a common approach even in the case of Abaqus which supports restart in GUI.

3

I worked 10 years with Abaqus and 8 with Ansys.

While Ansys has its limits and quirks, and quite a different “philosopy”, two features stand out strongly in the usability of the software:

  • having a result database; which allows to produce any kind of post processing results after the solution has been obtained,
  • having an integrated and straightforward restart system, which allows to stop a simulation, save everything and continue later, seamlessly. In multi-step analysis Ansys re-runs from the step where you have modified something. if it is the 6th step, it will re-run only the it, and you’ll have a single output, consistent with the input data. This makes complex non-linear solutions MUCH easyer.

In Calculix/PrePoMax it would be great to have at least some system to restart without all the complexity of checking the step, renaming files, adding keywards, command line, … joining files, …

I know it is complex, but I think it would be really a huge improvement.