Freecad is an OpenSource cad system already integrated with calculix and other solvers. 
A nastran thread is already on its forum. 
Vittorio 
https://forum.freecadweb.org/viewtopic.php?f=18&t=12753

An interesting project is ferespost, capable to process nastran results. 
Maybe it could be used also with Mystran or Nastran-95 op2 files. 
Vittorio

https://www.ferespost.be/

An input file format converter from Nastran to Code_Aster is available at

https://sourceforge.net/projects/nastrantocodeas/

Vittorio

TBD

Here is the original source code from NASA:
https://github.com/nasa/NASTRAN-95

Based on this, Thomas Hermann (along with Harry Schaeffer), created this version:
https://github.com/OdonataResearchLLC/NASTRAN-95

Later, it seems (but not exactly sure of the timeline), that Luca created this version for Linux, which was was later distributed with Ubuntu:
https://github.com/ldallolio/NASTRAN-95
I think this is a more user friendly version that is easier to set up on the host computer, but not sure. TBD item.

Note from Vittorio:
I also compiled successfully NASTRAN-95, both under linux (Ubuntu 16.04) and Cygwin/windows. Under ubuntu the simplest way is to use the debian version already available.

Bill pointed us to the full user manual (1382 pages). The important of this manual (unlike the one on GitHub), is that is has the "Quick Reference Guide", which is what most end users are used to (as opposed to the programming related aspects).

https://ntrs.nasa.gov/search.jsp?R=19720022271

Thomas Hermann has a large collection of documents here:

https://www.odonata-research.com/referen...talog.html

https://www.odonata-research.com/referen...talog.html

A theoretical manual is here:
https://ntrs.nasa.gov/search.jsp?R=19790019360

A list of elements is shown here:
A list of elements is shown here ( https://github.com/SteveDoyle2/pyNastran/issues/583 )

The older Intel MKL sparse solver has been removed. This was done because those libraries are no longer available and it was not a good sparse solver.

However, this means that a BDF should have the line "PARAM, SOLLIB, ZZPACK" to call LAPACK as the default solver. Otherwise, it will call the Intel solver by default, which is no longer available. I think the default should change to ZZPACK, but for for the meantime be aware of this item.

In other to best develop MYSTRAN, we should be aware of the other offerings.

CalculiX is an excellent FEA solver that has an ABAQUS-like input deck (the input deck is often interchangeable in same manner as MYSTRAN and NASTRAN are similar). This is a great advantage to those already familiar with ABAQUS. It also seems to be one of the most popular open source solvers.

Here is the website:
http://www.dhondt.de/

It is split into two aspects:
1. CalculiX CrunchiX (CCX) is the solver, which is developed by Guido Dhondt
2. CalculiX GraphiX (CGX) is a pre/post, which is developed by Klaus Wittig

A distinct advantage is that the solver has nonlinear capabilities. However, something important to notes is that all elements are 3D on the solver side. A user can specify a beam or shell element, but the solver internally expands those elements into 3D. This has some advantages and some disadvantages, but is not a "classical" approach to FEA.  I think this presents a bigger challenge for beam elements than shell elements. And one advantage is that shell elements automatically have transverse shear stiffness because they are ultimately 3D. Another thing to consider is that CalculiX only reports the beam results at the integration point (center of the beam element) and the user is often interested in the results at the nodes (ends of the beam element).

I have been impressed with CalculiX and have built some specialty pre/post programs with them ( www.espcomposites.com ) and (www.structuralfea.com)

----------------

There is some carry over from CaculiX to MYSTRAN:

1. The CalculiX developers are looking to incorporate a new sparse solver. We can learn a lot from their efforts.
2. CGX is a light pre/post that has some interesting capabilities. It uses an FRD file, which seems to be relatively straightforward. MYSTRAN could export a FRD file and CGX could be used.

MYSTRAN is largely compatible with programs that support BDF files. However, it does not currently have an OP2 output (will be developed later). While there are commercial programs that can use MYSTRAN, such as MSC Patran and Femap, these programs are expensive and are usually combined with their own solvers. Instead, this thread will present low cost or free/open pre/post software that works with MYSTRAN.


-------------FULL PRE/POST OPTIONS:-------------
A "Full Pre/Post Option" is considered to be a software that can create a BDF/mesh, apply loads/constraints, run the MYSTRAN solver, read MYSTRAN output, and post-process the results.

1D Elements (https://www.structuralfea.com/ )
A program that can use beam, rod, and spring elements in 2D space (linear static analysis, buckling analysis, natural frequency analysis). It has complete documentation and series of videos that explain how the program works.


-------------PARTIAL PRE/POST OPTIONS:-------------
A "Partial Pre/Post Option" is considered to be a software that read, modify, etc. BDF files (or output files). These programs can be used to interrogate models, but are not used to create a mesh, apply loads, etc. After the OP2 option is implemented in MYSTRAN, some of these programs can read results files.

pyNastran ( https://github.com/SteveDoyle2/pyNastran )
Using the BDF interface, you can read/edit/write Nastran geometry without worrying about field formatting. Many checks are also performed to verify that your model is correct. Using the OP2 interface, you can read large result files quckly and efficiently. Additionally, you can also extract a subset of the result data and write OP2/F06 result files.

FEX ( http://www.f-e-x.com/ )
A lightweight program (only 3MB) that can read and interrogate BDF files. It can be used to visually show the model, discover issues, measure, and perform various other operations. It has a built in tutorial and low learning curve. I found this to be a simple tool that is quite useful. It does not have post processing capabilities.


-------------TBD:-------------
M3DFEA ( http://www.m3dfea.com )
CalculiX GraphiX (F06 capability pending evaluation)
GMSH
Salome-Meca
Paraview

Dear all,
have a look at 
http://www.f-e-x.com/
FEX is a free program that can read  Nastran INPUT and view/check the model
Bye
Vittorio