How do you troubleshoot simulation if results are not same as in Abaqus?

General Questions
1

Hello I am doing simulation of bracket in PrePoMax and got displacement magnitude at 0.14 mm, same model with same BC and Loads in Abaqus are giving me 0.24 mm. How to judge which results are correct?

2

Since Abaqus and CalculiX share mostly the same syntax, the easiest way might be to convert the input file from one solver to run it with the other. You will find some tips for Abaqus → CalculiX conversion here (the other way around, it’s actually easier): A Guide to Modifying Abaqus Input Files for Use in CalculiX - CalculiX (official versions are on www.calculix.de, the official GitHub repository is at https://github.com/Dhondtguido/CalculiX).

Moreover, dev versions of PrePoMax support Abaqus format and even submission too. But CalculiX input files are usually submitted externally in such cases: Using standalone CalculiX

You could also just compare the input decks (at least without the mesh part) - even make a diff in any text editor to find some major differences.

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3

Thanks will check it for sure and try to see what went wrong

4

check if you are using 1st order elements. If so, I would advise you to use 2nd order instead

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5

I am using 2nd order by default.
Was checking same part in SimScale and I got same result as in Abaqus but in PrePoMax I can’t achieve it :confused:. Can I share with you pmx file if you guys can check if I missed something in settings?

6

Sure, without it we can only guess what could be wrong.

7

I run it 30 min ago and I got same result as in Abaqus and SimScale :slight_smile: . Don’t know what was wrong so I am not sure if I will be able to figure it out some day :smiley: . Anyway thanks for your help, if you are still interested you can check attached file.

Bracket_Issue_Solved.pmx (6.0 MB)

8

The only remark I have is that you could refine the mesh and possibly use shell elements.

Bracket_Issue_Solved_shell.pmx (2.7 MB)

9

Great thanks a lot @FEAnalyst. Did you create shell surface with PrePoMax or with some CAD software?

10

I used FreeCAD to extract the midsurface from this part (exported to STEP from PrePoMax), then exported it to back to STEP and imported to PrePoMax.

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11

Thank you for feedback :slight_smile: