Elmer Discussion Forum

Hi all,

I'm new at this forum, so I'm sorry if this is a repost, I tried to search for it, and couldn't find an answer.

I'm a university student, and in my classes we use ProEngineer. I know that ProEngineer can save their files as .igs formatted files for use by other analysis programs.

My question is, how do I get ProEngineer files, or .igs files into a compatible file or mesh formatted file to use for analysis.

Any links, tips, and walk throughs would be appreciated.

Thanks in advance.

Hi, You could try Gmsh which eats .igs and writes .msh that may be opened by Elmer tools. -Peter

If it doesn't work well with igs, try to save your geometry in step format. gmsh often handles step better than igs.

Matthias

If the case is 3D, then exporting in STEP format is in my opinion the best and ElmerGUI can perform the meshing directly. If on the other hand the case is 2D, then export in IGES and perform meshing in Gmsh.

Hi,

I just have tried to mesh a 3D STEP geometry in Elmer. Opening it with ElmerGUI and selecting mesh->remesh resulted in a crash. Is this supposed to work? I would be most interested in a possibility to mesh a 3D geometry directly in Elmer, as in gmsh there are many problems with overlapping faces.
As for IGES and gmsh, I have made the experience that the IGES export was not handled correctly in gmsh, whereas the STEP export was represented correctly.

Matthias

I've managed to mesh quite complex solid models in elmergui, exported as STEP (from Catia). Anytime I need to run a 2D simulation and especially if the surface has trimmed regions, I always export in iges and mesh in Gmsh. There's a difference in how edges are treated between step and iges. Iges will give you more resolution around corners and curved geometry whereas Step surfaces will mesh much more uniformly. These are my experiences with NURBS patches made in Alias Studiotools.

Sometimes I do get issues with 3d STEP file meshing but then again these situations often arise from modeling too freely/lavishly in Cad. I think you have to keep your modeling simple enough to ensure meshing compatibility..

Hi pamakela,

here is a 3D geometry in STEP format. Could you test if you manage to mesh it with Elmer? If so, how exactly do you proceed?

Thank you in advance,

Matthias

Hi,

I tried meshing your Step file but meshing crashed here as well. How did you build your geometry? Looking at the isoparms and other curves it seems you made it in a surface-modeler? If so, I would recommend stitching the surfaces into a solid in a solids-modeler and then only STEP-export surfaces, nothing else.

Hi,

thank you for testing my test case.
So at least there was no trivial error on my side.
The geometry was built with Solidworks in our mechanical department, and I do not know much of how 3D-CAD programs represent geometries. So I have no idea if Solidworks is a solids-modeler or a surface-modeler (I would guess, however, that it is a solids-modeler). I don't know if your recommendation is feasible with Solidworks, but I will ask my colleagues.
However, if I only export the surfaces, wouldn't I have to rebuild the solids manually?
The problem is also that every solid has its own outer faces, so if two solids touch, there are duplicate faces resulting in a nonconformal mesh. Do you think this would not be the case if I export only surfaces?

Thank you,

Matthias

SW can do both solids and surfaces but IMO is considered primarily a solid-modeling software. I tried to mesh your step file in Gmsh as well, but that failed also. I did however notice there's a smaller duplicate of the object contained inside of the model and I'm fairly convinced that this is the source of the problem (view your Step file in Gmsh and see for yourself).