hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Info about new community or project announcements, implemented features, classes, modules or APIs. Might get technical!
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johnwang
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by johnwang » Tue Jul 21, 2020 7:33 am

nic wrote:
Tue Jul 21, 2020 7:08 am
the user manual, and I could'nt find some important cards (at least to me):
The user manual is the um folder. All text file. For bulk data, read bulk. txt.

There is CQUAD4, PCOMP.

There is no RBE2/RBE3. But there is CRBE2/CRBE3. Are they the same?

No CBUSH found. You could use MYSTRAN. That program has CBUSH card.
crbe2.jpg
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Last edited by johnwang on Thu Jul 23, 2020 1:19 am, edited 2 times in total.
Pre/Post processing CAE workbenches for FreeCAD (hfcNastran95, hfcMystran, hfcFrame3DD, hfcSU2)
https://github.com/ceanwang
janpl
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by janpl » Tue Jul 21, 2020 7:46 pm

vocx wrote:
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
Hello everybody ,

Dear @vocx , NASTRAN is common name family of probably most famous FEM solvers on the world.
history of its evolution from NASA and MC Neal partner is fantastic lession to learn not only from engineering and CAE side .
Small resaearch by google can spot more interesting materials forexample academic and comercial papers ...
I admire calculix features but for many engineeers and me also NASTRAN is rock.

Dear @nic , you are perfectly right. Main stream incarnations of NASTRAN are now (after court fight) available commerciallyand are in many industries ( also maritime ) standard an primary tools.

I add to your list also Hyperwork package with Optistruct solver with >100 cards fully compatible with NX,NeI and MSC Nastran .

Dear @johnwang . Thanks for you effort. You done very interesting work. I want to try testing NASTRAN-95 with your module but have small problem...:
where can I found compiled EXE of NASTRAN-95 ? is there any repository linked for Windows ?

Revive and implementing in FreeCAD pre/post processing opensorce version of NASTRAN-95 may be my opinion very usefull for many students. Big list educationalmaterials is available in public domain based on NASTRAN solver decks (static/modal/buckling and also dynamic)
Thanks in advance ,
Jan
FEA_Stress
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by FEA_Stress » Wed Jul 22, 2020 12:07 am

A few additional comparisons:

CalculiX is a great solver. Perhaps the biggest disadvantages are that it does not have "true" beam, shell, and spring elements. Rather, all of those elements are internally expanded into 3D. There are a variety of challenges with this, but it still a great solver (and especially great for solid elements since it has nonlinear capability).

On the other hand, all major commercial solvers has a suite of "true" elements (rods, beams, shells, MPC's, solids, springs, etc.). From there, there are only handful of options in the open source arena (especially for those with "classical" style input decks - as opposed to Code_Aster). NASTRAN-95 is one option, but has its own challenges. Alternatively, MYSTRAN (www.mystran.com) is a NASTRAN-like program that is more modern and still in development. Here is a comparison between the two:

https://www.mystran.com/forums/showthread.php?tid=4
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johnwang
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by johnwang » Wed Jul 22, 2020 3:47 am

Test case with PCOMP card

https://github.com/nasa/NASTRAN-95/blob ... 01321a.inp
pcomp1.jpg
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Pre/Post processing CAE workbenches for FreeCAD (hfcNastran95, hfcMystran, hfcFrame3DD, hfcSU2)
https://github.com/ceanwang
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bernd
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by bernd » Wed Jul 22, 2020 10:25 am

a reference ... FEM_Solver
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by FEA_Stress » Wed Jul 22, 2020 4:28 pm

bernd wrote:
Wed Jul 22, 2020 10:25 am
a reference ... FEM_Solver
There are many solver options. The challenge is knowing which ones are still being developed, which have good documentation, strong user base, pre/post support options, open vs closed, etc.

One practical perspective is that CalculiX is largely compatible with ABAQUS. This means those who have spent months/years learning ABAQUS can transition to CalculiX with little effort...and vice versa. The same is true for NASTRAN (MSC/Nastran, Siemens, AutoCad), which is very similar to NASTRAN-95 and MYSTRAN. For the commercial programs, the documentation is very extension and there is a large user base, so the open source versions can piggy back off that.

As a long time user of ABAQUS and NASTRAN (aerospace industry), both CaculiX and NASTRAN-95/MYSTRAN are easy to work with. And if you were to work with those open source versions, it might be more attractive to a potential employer. It may also make sense for small businesses that don't have the funding for the commercial versions but want to be able to work with larger companies (the input decks are the same/similar).
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bernd
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by bernd » Wed Jul 22, 2020 5:35 pm

FEA_Stress wrote:
Wed Jul 22, 2020 4:28 pm
bernd wrote:
Wed Jul 22, 2020 10:25 am
a reference ... FEM_Solver
There are many solver options. The challenge is knowing which ones are still being developed, which have good documentation, strong user base, pre/post support options, open vs closed, etc.
+1

BTW: Have you tested FreeCAD FEM? Main solver of FreeCAD FEM is CalculiX. Furthermore Elmer is well supported too.
janpl
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by janpl » Wed Jul 22, 2020 6:06 pm

Is there a place with precompiled NASTRAN-95 binaries for windows ?
I can't find any for testing.
FEA_Stress
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Re: hfcNASTRAN95 - Pre/Post processing for NASTRAN95

Post by FEA_Stress » Wed Jul 22, 2020 7:01 pm

I need to learn FreeCAD and look into the options further (my main interest is in pre/post support for MYSTRAN). While CalculiX is a great solver (and one of best open source solvers), it is does not have true beam and shell elements. This can present major issues, but CaclculiX is great if you want to use only solid elements. In the aerospace industry, the beam, shell, and connector elements are the workhorse elements (not the solid elements), so NASTRAN-95 or MYSTRAN are better for that.

Regarding NASTRAN-95, there is some information here ( https://www.mystran.com/forums/forumdisplay.php?fid=11 ). The main issue is that it is hard to find developers, it has some old elements, and there isn't much of a community in support of it.

However, if you look at this thread ( https://github.com/nasa/NASTRAN-95/issues/5 ), you will find Harry Schaeffer's email. He has a compiled Windows version that has a lot of improvements over NASTRAN-95. There is also documentation for it and it is only $100. From what I have seen, NASTRAN-95 is going to be quite difficult to work with (and documentation is not good). So either ComLab or MYSTRAN might be better choices.
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