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Download GUI (latest is from 2024/3/25)
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pyNastran is an interface library to the various Nastran file formats (BDF, OP2, OP4). 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 quickly and efficiently. Additionally, you can also extract a subset of the result data and write OP2/F06 result files. For a more detailed list of features, see:
Using the pyNastran GUI, you can read in Nastran models and quickly view results for a model. While it's no FEMAP/Patran, it can replace many tasks that would otherwise require a commercial program.
This is a mainly a bug fix release. There's also a couple of new acoustic cards and MSC's STRESSA table that were added to fix some errors.
The force/bending moment diagrams have also been improved:
See pyNastran release notes for details on the other changes.
It's been a while since the update, but I've had a more time lately. MSC also provided a copy of MSC Nastran free of charge to help support the project, so modern MSC Nastran support is much better.
Finally, the GUI has received a lot of work recently including:
Programmatics:
BDF:
OP2:
model.cquad4_stress
is now found in model.op2_results.stress.cquad4_stress
. Same goes for other stress, strain, force, and strain_energy components. This will hopefully make things a bit easier find.GUI:
See pyNastran release notes for details on the other changes.
This is a bug fix release mainly to address dependency changes:
Programmatics:
There are also at least 33 bugs fixed and a few features added from the 1.4 release (e.g., pathlib support, subcase limiting in the flutter F06 parser).
See pyNastran release notes for details on the other changes.
This is a bug fix only release outside of:
>>> subcase.add_set_from_values(set_id, values)
which was overly complicated to do before.
Programmatics:
See pyNastran release notes for details on the 54 bug fixes. Not too bad for 2.5 months!
With Python 2 now officially dead, it's time for a new killer feature to get the last few people to switch.
There is now support for writing OP2 files! They're difficult to create from scratch, but modifying an existing one isn't difficult. This includes geometry support.
In addition, many new OP2 results have been added. Modern NX Nastran should work much better.
Programmatics:
BDF:
bdf scale
, which takes arbitrary mass, length, time, pressure, or velocity scale factors (3 of 5) to apply a scaling lawOP2:
GUI:
F06:
Many bug fixes, and a few more details on features, can be found in the
This result has been superseded by 1.3.2. The PyPi page was fixed.
I keep saying to myself there's not much to add, but Nastran is huge. Beyond HDF5 support in the BDF, I'm a huge fan of the new ability to keep track of which include file a card came from and write it as a separate file. It's limited in usefulness, but very handy in certain cases. There's a new (still preliminary) superelement capability. I'm far from a superelement expert, but it's probably useful.
The OP2 reader now supports SORT2 along with much improved random results reading. If you're using 60+ GB OP2s, you probably have had issues with RAM usage in the past. With the new ability to dump the OP2 directly to HDF5, this should not be an as much of an issue. It's not 100% implemented, so let me know if you need it for another result.
Regarding the GUI, there are also some new features. Groups work a bit better, but aren't quite perfect. Logging has been dramatically sped up, so the GUI loads faster, and you can load Nastran models even faster if you disable additional results (e.g., element quality).
Finally, Python 2.7 is end of life. Numpy, scipy, and matplotlib have all dropped Python 2.7 support. It's time for pyNastran to as well. The OP2 reader is 30% faster in Python 3.6+ than Python 2.7, so it's not all bad!
Programmatics:
BDF:
373 cards supported (up from 343)
added abiltity to write models to separate include files
>>> model = BDF()
>>> model.read_bdf(bdf_filename, save_file_structure=True)
out_filenames = {
bdf_filename : bdf_filename_new,
include_filename : include_filename_new,
}
>>> model.write_bdfs(out_filenames, relative_dirname=None, is_windows=None)
>>> ifile = model.grids[1].ifile
HDF5 import/export
>>> model = read_bdf(bdf_filename)
>>> model.export_hdf5_filename(hdf5_filename)
>>> model_new = OP2()
>>> model_new.load_hdf5_filename(hdf5_filename)
preliminary superelement support
>>> model.read_bdf(bdf_filename)
>>> model.superelement_models[1].nodes
OP2:
reorganization of random op2 results into op2.results.psd (or ato, no, crm, rms) to aid in finding data
reorganization of op2 class to reduce number of functions in the object. This affects any custom table reading.
improved optimization response reading
limited SORT2 support
fixed CD transformation bug for BOUGV1 and BOPHIG1 tables
Improved HDF5 export/import support (e.g., matrices, random results)
Can optionally save directly to HDF5 instead of numpy (limited).
Loading OP2s to an HDF5 file to decrease memory usage
>>> op2_model = OP2()
>>> op2_model.load_as_h5 = True
>>> op2_model.read_op2(op2_filename)
OP2Geom:
GUI:
Known issues:
This result has been superseded by 1.2.1. See release notes for details.
See v1.1.0 for information regarding enhancements.
See v1.0.0 for information regarding enhancements.
See v0.8.0 for information regarding enhancements.
See v0.7.2 for information regarding enhancements.
Version 0.6 improves BDF reading. The reader is more robust and also requires proper BDF field formatting (e.g. an integer field can't be a float). Additionally, cards also have a comment() method.
Marcin Gąsiorek participated in the latest pyNastran under the European Space Agency's (ESA) "Summer of Code In Space" SOCIS program. The program provides a stipend to students to work on open-source projects. He did a great job of simplifying code and creating nicer documentation.