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  1. Dave442

    Downgrade .odb version from 6.14 to 6.10/6.12?

    There is capability to build a new odb from an existing odb. It's described in the scripting manual, with an example. These guys made a plug in for doing it: https://info.simuleon.com/blog/abaqus-odb-extractor-and-builder-tool-oebt-plug-in However, I don't know if it's possible to build a new...
  2. Dave442

    Downgrade .odb version from 6.14 to 6.10/6.12?

    re-run the analysis with an older installation?
  3. Dave442

    Dynamic implicit analysis error

    1073741795 is a windows error code not an Abaqus error. Your model is trying to do something that the operating system doesn't like. There are many reasons why this could happen so it will be hard to diagnose here. If you scroll down through this thread, there's a post by Luca Di Stasio with...
  4. Dave442

    impact contact force

    be careful using CFN history output. If I remember it correctly: CFN1, CFN2 and CFN3 are the scalar sum of contact force components in the three global directions. For certain geometries (e.g. cylindrical) equal and opposite forces will cancel each other.
  5. Dave442

    UMAT of beam B23

    Check for UMAT in the "User Subroutines" guide in the 2018/2019 Abaqus documentation: "DDSDDE(I,J) defines the change in the Ith stress component at the end of the time increment caused by an infinitesimal perturbation of the Jth component of the strain increment array." This section also...
  6. Dave442

    ABAQUS CFD verification with Darcy Pressure equation

    i think if you can just neglect the entrance length, which can be calculated. you should be able to calculate dP between the start/end of the fully-developed region. then use that for your validation - saves having to extend your domain. glad you got sorted anyhow!
  7. Dave442

    ABAQUS CFD verification with Darcy Pressure equation

    Maybe I am thinking of a slightly different form of the equation: dP = L*(128/pi)*[(mu*Q)/D^4] I guess just double check you're using an appropriate mean velocity. Rather than the value you define at the inlet. Since it varies as a function of tube radius.
  8. Dave442

    ABAQUS CFD verification with Darcy Pressure equation

    I might be wrong but I think you're meant to use flowrate in m3/s rather than velocity in m/s for v. Also, I think Darcy equation applies only to fully-developed laminar flow and doesn't take into account that you have an entrance length where the flow develops. You could use an equation to...
  9. Dave442

    An-out-of-memory error

    to reduce the size of your model can you reduce the mesh or exploit symmetry or planar conditions? alternatively, if you have the resources, can you run the analysis in parallel?
  10. Dave442

    An-out-of-memory error

    Right click on your job in CAE and select Edit. There is a "memory" tab in the window that appears. It allows you to specify the memory allocation for the job. Is your model huge? If not, have you tried restarting your machine?
  11. Dave442

    Nonlinear analysis - failure to converge

    what's the purpose of the analysis? Is the balloon compliant, semi-compliant or non-compliant - this dictates what assumptions you can make to simplify the model. You also said the balloon is inflated by specifying a displacement - how does that work? Surely it should be pressurized? I've...
  12. Dave442

    Reading & comparing Input files

    ExamDiff - Freeware Visual File Comparison Tool https://www.prestosoft.com/edp_examdiff.asp Also Notepad++ with Compare plug-in as FEA-way suggested.
  13. Dave442

    Wrong force values

    i create a single element and verify the stress-strain output matches the test data for each deformation mode (uniaxial, biaxial etc.). this verifies the defined correctly and behaving as expected. if the FE output doesn't match test data something may be defined incorrectly. Abaqus has a...
  14. Dave442

    Wrong force values

    if you're confident in your analysis and your output I would query the test data: was material processing and/or pre-conditioning taken into account? were temperature and rate effects taken into account? could the materials have anisotropic properties? was the hyperelastic material model...
  15. Dave442

    What's wrong with Abaqus.inaccurate results without errors/warnings (seam crack)

    when you performed your merge you must have a section where the nodes on opposing faces are not coincident. when you do the merge CAE will highlight the nodes that will be merged together in purple. I would check that these problem nodes are highlighted at this stage. You may have to adjust...
  16. Dave442

    training/workshop analyzing fea models.

    i use a commercial FE code called abaqus a lot. i've found their training courses to be very helpful over the years. they offer courses on a wide variety of topics and the instructors have always impressed. they have also been willing to deliver bespoke courses covering a range of topics...
  17. Dave442

    Wrong force values

    A couple of suggestions: CFN is total contact force due to contact pressure. CFS is total contact force due to friction, and CFT is total contact force due to CFN + CFS. Are you looking at the right output variable? Is friction a factor in your test? Also, i think CFN and CFS are resultant...
  18. Dave442

    Wrong force values

    How are you extracting/summing the contact forces?
  19. Dave442

    Modelling one geometry several times due change in one dimension

    Yes - I've only ever used this approach for 3D modelling. Most 3D parts are created using 2D sketches that define extrusions/revolutions/cuts and can be parameterized/constrained. Using this approach you can update sketch parameters and geometric operations, partitions, seeds and assembly...
  20. Dave442

    Modelling one geometry several times due change in one dimension

    The parameter manager in the sketch module can be used to do this. You need to constrain your 2D sketch well for this to work. If done correctly you can update your dimensions using the parameter manager and the geometry, partitions, seeds and assembly will update automatically. Then you just...

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