DXF Import feature?

Feature Requests
1

Hi,
Is there a possibility of add a DXF import feature for 2D simulations?

2

DXF format would be good for beams but for 2D (plane stress/strain, axisymmetric) simulations one would also have to convert the wires to faces.

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3

point, line, surface and solid element could be possible to be imported to another readable format.

using available opensource DXF library may it make less complicate in the task.

4

Is there a possibility of add a DXF import feature for 2D simulations

What for?

  1. Practically any CAD can convert a DXF file to one of the formats acceptable by PrePoMax.
  2. There a lot free online CAD format converters for the same purpose.

Due to these reasons even some proprietary FEM pre- and postprocessors do not accept DXF. IMHO PrePoMax is not and should not be a CAD substitution program.

5

Just for opening DXF file as a model for 2D analysys- not for using PrePomaX as CAD,

didn’t known that:

But this gave me an idea, to how to make a model in my 3D cad software, for that kind of analyses- extraction of one of surface from solid model, and exporting this in IGES format works.

Thanks!

6

DXF is an old format, many CAD programs supported and it less complex than IGS/STP. To my understanding not all CAD supported these format i.e AutoCAD LT and IntelliCAD standard versions.

many pre-processor FE also supported a DXF files, mostly in line and surface object for example: Nastran, SAP2000, GiD, Midas etc.

but for me it’s only good alternative file format for completeness, not a must have feature.

7

Look at this problem a bit realistically. Just now we have only one PrePoMax developer. His free time is quite limited and very valuable for all us. In my opinion, it is not a good idea to waste this time in order to implement the simplest operation that can be done easily using either free tools like FreeCAD or on-line converters.

PrePoMax is an excellent pre- and postprocessor for CalculiX first of all. Unfortunately, not all CalculiX cards are implemented in PrePoMax. Again, only in my opinion, improving CalculiX support in PrePoMax is more important for most users at the moment then addition of one more CAD format.

BTW, much more mature CGX also does not support DXF, although a free DXF2FBD converter is available at Github for those who need it. Similarly, GMSH also does not support DXF directly.

3 Likes
8

Yeah, to prepare 2D models for PrePoMax I often use Downgrade in FreeCAD which breaks a solid model into separate faces. Then I can delete the unnecessary faces and export the needed ones.

9

Thanks!
It will solve my problem.

10

dxf2fbd is my first time to understand dxf file formats, i learn much from original codes of GMSH developer. the code has been try to porting to python codes, to parse point, line and surface object, text, layer,etc but not finished yet.

actually these small codes can read point, line and arch/circle in 3d coordinate inputs not only 2d. but it’s not working well for arch/circle objects since difficulty in defining it’s normal plane in 3d.

i did not continue to make some improvement since there’s another interesting ways using an available opensource dxf libraries. it have many advantages including the capabilities to writing, not only reading or parsing.

11

At the moment, I agree with @i_rokach. There simply are too many other things I have to implement. And I primarily try to add features that are helpful to as many people as possible and are not possible to perform using other tools out there.

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