nasa / nastran-95

NASTRAN-95

NASTRAN has been released under the
NASA Open Source Agreement version 1.3.

NASTRAN is the NASA Structural Analysis System, a finite element analysis program (FEA) completed in the early 1970's. It was the first of its kind and opened the door to computer-aided engineering. Subsections of a design can be modeled and then larger groupings of these elements can again be modeled. NASTRAN can handle elastic stability analysis, complex eigenvalues for vibration and dynamic stability analysis, dynamic response for transient and steady state loads, and random excitation, and static response to concentrated and distributed loads, thermal expansion, and enforced deformations.

NOTE: There is no technical support available for this software.

nastran-95's Issues

What are the ouput files formats I can create?

Nastran substracting

Hi, I am trying to understand substracting in Nastran.
I am studying verification example 2-2 (Windmill panel sections for Automated Multi-stage Substructuring....).
When I run "run1"(folder D02-02-1A) I am getting output, as in verification folder, but when I do run 2, (folder D02-02-2A), I am getting error in out file. I do not understand how can I use input files with separate runs , which are in separate folders. Every time it looks that sof file is created in different folder, so how next run knows that result data are stored in sof in other folder? I cannot see in inp files any reference to other folders. What binds all separate runs results together?
I stacked at this step, and cannot find answer in manuals.
Kris

Nastran-95 input file extension

Nastran file extension: *.nas
Abaqus file extension: *.inp

Nastran-95 file extension: seams *.inp ?

If the above would be true, it would be very confusing ...

How best to contribute?

Hi,

I would like to contribute to this project but don't know how best to get involved. Is there any consensus on what is needed / where to start?

Specific items I think are needed:
FAQs: simple instructions on how to compile; stable version identification; summary of key features; summary of 'missing' features; discussion of how documentation relates to current version; good pre/post processors.

Long term issues: discussion of any licence issues; test problem library; plans for new features...

Are there mechanisms for doing this via Githib without forking to add documentation?

Thanks in advance!

NASTRAN Discord channel

Hello everyone,

Recently we created a Discord channel for NASTRAN to get the community together and revive some of the underappreciated projects out there. So far we have the developers of pyNASTRAN, MYSTRAN, and some FreeCAD folks over there:

https://discord.gg/h9zDcHH

you are welcomed to join and invite the rest fo the community.

Best,
Foad

limiting number of elements

Hi,
I have been using Nastran to analyse plates.
It seems to work below 11000 elements,
When I use mesh sizes where I reach 11000 elements and I have single subcase, Nastran does not show in output file all supports results, and internal forces seem also to be wrong.
If I have two subcases, then Nastran does not show any results.
I am assuming this is related to number of elements or size for output file.
Is there any flag or way I can change max elements number limit ?
The same plate with eg. 10000 elements works fine (the same size, loads, supports)
Regards,
Kris

Modal Effective Mass

Does anyone know how modal effective masses were calculated when using NASTRAN95 please?

Looking at various sources from around this time it looks like it can only be done with a bit of DMAP?

If that's the case does anyone know how the rigid body displacements can be calculated automatically?
I think more modern versions use the VECPLOT DMAP module to do this:

Performs utility functions on g-set size matrices, including computation of resultants, transformation from one coordinate system to another, and generation of rigid body matrices.

Compiling instruction

Can someone explain how to compile this marvel? Will it work on a PC compiled with GNU Fortran? There are no makefile nor instructions for compiling. Thanks in advance!

Are there any instructions on how to install and run Natran-95?

I need to install this package on Window 10

but searching on the web there is no clear tutorial on installation. while I click on the nastran.exe on this package, I get windows error the file not found in directory.

could anyone tell me if there is a compiling step missing ? just if you know how to install it, and also use it, please write an answer? it will be a great source for internet

add topics

I suggest adding topics such as finite-elements, finite-element-analysis, nastran in the About section.

Nastran original

NastHelp.exe Windows 10 Version User's Manual

https://github.com/ceanwang/NASTRAN-95/tree/master/um

Just run nasthelpWin.exe in that um folder.

Please consider using a FSF-accepted free license

This project uses a license which is not recognized by the FSF ( http://www.gnu.org/licenses/license-list.html#NASA )
As many GNU/Linux distributions uses this list to accept/reject software, this limits the diffusion of this great software.

Please consider using a more standard license (GPL, BSD, MIT, MPL, Apache, etc).

Error while running examples

Hi everybody,
I am at the very beginning in using nastran-95 on my Ubuntu system, so I thought starting from the provided examples could be a good idea.
The problem is that I can not run successfully even the examples included in the installation folder!

Am I doing anything wrong?
What I did is:
install the nastran package with "sudo apt install nastran", then go to the examples directory "/usr/share/doc/nastran/examples", chose one random example like "d01011a.inp.gz", extract it to a generic folder and run from the terminal "nastran d01011a.inp" in that folder.

I got some output files but they are always containing a bunch of string like those. Does anybody knows how to run at least the provided examples?

0*** USER FATAL MESSAGE 8020, SYNTAX ERROR NEAR COLUMN 16 IN THE FOLLOWING CARD-
*SBST 1, 3
0 1 2 3 4 5 6 7 8
1 0 0 0 0 0 0 0 0
0 USER FATAL MESSAGE 8020, SYNTAX ERROR NEAR COLUMN 16 IN THE FOLLOWING CARD-
*SBST 1, 3
0 1 2 3 4 5 6 7 8
1 0 0 0 0 0 0 0 0
0 USER FATAL MESSAGE 8020, SYNTAX ERROR NEAR COLUMN 16 IN THE FOLLOWING CARD-
****SBST 1, 3
0 1 2 3 4 5 6 7 8
1 0 0 0 0 0 0 0 0

op2 file

Do anyone know how to output op2 file?
I am confused on how to get op2 file.

Equivalent DMAP commands

Does anyone know the equivalent NASTRAN-95 DMAP commands for the following please?

1. MESSAGE - e.g. MESSAGE//P1/P2/.../Pn$ or a command to write arbitrary messages to the output file

2. Piecewise matrix multiplication of whole matrices - possible in other versions using DIAGONAL A/B/OPT/POWER$ where OPT is WHOLE.

BEAM and BAR are not supported, Is it limited in capability or there is a workaround?

I have observed that this version of NASTRAN does not support, BEAM and BARs , the same way, PLOAD1 other NASTRAN feature which is there in commercial versions are missing here.
Is it a limitation or my understanding is not correct? Is there any workaround to do analyse a Beam ?

Error running large problem

Hi, I tried to run a large problem available from freeBSD distribution of NASTRAN-95. It runs and completes the eigenvalue extraction but seems to fail when writing the results in the output file. Anyone has a clue about what could be the problem?

Input and output files attached in a zip file.

Running latest nastran distribution of Ubuntu.
large_problem3.zip

Regards.

Why plt file is empty?

After solving a case, I got the result in F06 file. But the plt file is always empty. What is the setting to output result into plt file?
Which FORTRAN subroutine writes result into F06 file?
Thanks.