hfcNASTRAN95 - Pre/Post processing for NASTRAN95

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johnwang
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hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by johnwang » Fri Jul 17, 2020 5:32 am

Hi,

The project is at https://github.com/ceanwang/hfcNastran95

Some case photos could be seen from this post:
https://forum.freecadweb.org/viewtopic.php?f=18&t=39234

and demo case:
https://forum.freecadweb.org/viewtopic.php?f=18&t=48982

Regards,

John
Last edited by johnwang on Sun Jul 26, 2020 10:45 pm, edited 1 time in total.
Pre/Post processing CAE workbenches for FreeCAD (hfcNastran95, hfcMystran, hfcFrame3DD, hfcSU2)
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Kunda1
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by Kunda1 » Fri Jul 17, 2020 11:15 am

johnwang wrote:
Fri Jul 17, 2020 5:32 am
Hi,

The project is at https://github.com/ceanwang/hfcNastran95

Some case photos could be seen from this post:
https://forum.freecadweb.org/viewtopic.php?f=18&t=39234
Very cool.
Can you add a short summary to the first post so users have a context (besides linking to another post)?
Also can you add a mention of your vision for this solver? What are targets on the Roadmap?
How can Nastran95 help in the scheme of things especially with FEM moving forward?
Thanks!
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by vocx » Fri Jul 17, 2020 1:29 pm

Kunda1 wrote:
Fri Jul 17, 2020 11:15 am
...
Can you add a short summary to the first post so users have a context (besides linking to another post)?
...
Not to discourage the conversation but Nastran is old as hell. I'm willing to bet that Nastran is older than most FreeCAD users (although there is certainly a lot of 60 year olders using FreeCAD).

Nastran95 was recently open sourced (in 2015?), so it's a novelty, but that's about it; the solver code hasn't been touched in 25 years or so. It's like Microsoft open sourcing a 1992 version of DOS/Windows. It's ok, but it's not particularly impressive when you have more modern solvers actively being developed in present day (like CalculiX which already works with the FEM Workbench).

So, this workbench is okay, but it's mainly for old users of Nastran who want to use that old piece of software. Nastran95 is essentially a dead end. It has no active development and has no support, so there is no "future" to speak of. It would be like implementing an emulator for a 1990 DOS system; if people do it, it's just for the fun of it, as a learning experience, although it may not have a practical use nowadays. Of course, open sourcing Nastran95 is helpful for students of mechanical engineering and mathematics who want to learn more about the practical implementations of the finite element method (FEM). So there is that, mathematics don't change, so it's nice to see the theoretical concepts being applied.
Last edited by vocx on Fri Jul 17, 2020 2:57 pm, edited 1 time in total.
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by nic » Fri Jul 17, 2020 2:24 pm

vocx wrote:
Fri Jul 17, 2020 1:29 pm

Not to discourage the conversation but Nastran is old as hell.
Still widely used at least in Aircraft industries (Airbus, Boeing, and a good proportion of sub-contractors as I am).
I'd love to be able to run an open-source Nastran!
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by Kunda1 » Fri Jul 17, 2020 2:53 pm

nic wrote:
Fri Jul 17, 2020 2:24 pm
vocx wrote:
Fri Jul 17, 2020 1:29 pm

Not to discourage the conversation but Nastran is old as hell.
Still widely used at least in Aircraft industries (Airbus, Boeing, and a good proportion of sub-contractors as I am).
I'd love to be able to run an open-source Nastran!
TIL ("Today I Learned")
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by nic » Fri Jul 17, 2020 3:27 pm

Actually, Nastran's world is quite active. Three main "branches" co-exist (there are more of them, but those are the most widespread):

* MSC Nastranhttps://www.mscsoftware.com/fr/product/msc-nastran
* NX Nastran (siemens) https://www.plm.automation.siemens.com/ ... stran.html
* NEI Nastran (Autodesk)https://www.autodesk.com/products/nastran/overview

Femap (Siemens) and Patran (MSC) are the main legacy pre/post softwares for Nastran.

The trend is actually to integrate more and more the Nastran's solver in the core of CAD/PLM softwares such as the name of "nastran" can look more "hidden" than before.

One thing I really miss in other solvers I had the occasion to try is MPC constraints abstracted as 1D-like elements (cf. https://www.predictiveengineering.com/s ... -and-cbush)
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by vocx » Fri Jul 17, 2020 3:35 pm

nic wrote:
Fri Jul 17, 2020 2:24 pm
Still widely used at least in Aircraft industries (Airbus, Boeing, and a good proportion of sub-contractors as I am).
But that doesn't mean it's exactly the same Nastran95 that is open sourced. The still proprietary versions have probably grown more complex.

The basic source code is there, free; the problem is there is not much more than that; it's basically just a collection of Fortran files, some test files, and a couple of manuals.

https://github.com/nasa/NASTRAN-95
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by bernd » Tue Jul 21, 2020 5:11 am

nic wrote:
Fri Jul 17, 2020 2:24 pm
vocx wrote:
Fri Jul 17, 2020 1:29 pm

Not to discourage the conversation but Nastran is old as hell.
Still widely used at least in Aircraft industries (Airbus, Boeing, and a good proportion of sub-contractors as I am).
I'd love to be able to run an open-source Nastran!
But not the nastran from 1995 ?!?
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bernd
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by bernd » Tue Jul 21, 2020 5:14 am

This workbench supports nastran mesh reader as well as nastran result reader.

Support for these file formatts would be very handy in master FreeCAD too! How about integrating them into FEM inout modules? https://github.com/FreeCAD/FreeCAD/tree ... m/feminout
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by nic » Tue Jul 21, 2020 7:08 am

bernd wrote:
Tue Jul 21, 2020 5:11 am
But not the nastran from 1995 ?!?
Well, I don't know where to find the list of cards available in NASTRAN95. I just had a quick look on the user manual, and I could'nt find some important cards (at least to me):

* CQUAD4 !! (isoparametric membrane-bending or plane strain quadrilateral plate element) - I'm surprised this one wasn't existing at this time :-)
* PCOMP (Layered Composite Element Property)
* RBE2/RBE3 (Rigid Body elements)
* CBUSH (Generalized Spring-and-Damper Connection)

I'll check further once I'm back at home in two days. Cloning the repo takes too much time with my current connection.
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