ElmerGUI crashes opening large .unv file

[thiennz]

I have been running into problems opening a .unv mesh I've create in SALOME (~80MB). I would attach it here but it's too big. I am also running Elmer and SALOME on Windows 11.

When I try to open the .unv file in ElmerGUI the program becomes unresponsive and crashes abruptly after a few seconds. I have also tried converting the .unv mesh into an elmer mesh using ElmerGrid but it hasn't been able to produce an output file. The command line output is below:

Code: Select all

Elmergrid 8 2 .\Diamond.unv

Starting program Elmergrid
Elmergrid reading in-line arguments
Output will be saved to file .\Diamond.

Elmergrid loading data:
-----------------------
Reading mesh from universal mesh file .\Diamond.unv.
First round for allocating data
Units dataset content is currently omitted!
Part UID = 1
Part name = SMESH_Mesh
Coord system name = Global
There are 281539 nodes in the mesh
Element type range in mesh [203,510]
Allocating mesh with 281539 nodes and 244629 10-node elements in 3 dims.
Physical index interval is [2,2]
Group index interval is [1,1262]
Using offset 1261 for physical indexes
Second round for reading data
Reading Coordinate system information
Reading node coordinates
Reading element topologies
Reading element groups in mode 2467
Reading 1:th group with index 1 with 2039 entities: rx1
Element type range in group is [510 510]
...
Reading 1262:th group with index 1262 with 14 entities: Face_45
Element type range in group is [306 306]
Moving bulk elements to boundary elements
Leading bulk elementtype is 510
Trailing bulk elementtype is 203
Checking that different dimensions have unique boundary tags!
Tag interval for boundaries: [1 1263]
No overlap, no offsets needed!
There are 31677 (out of 244629) lower dimensional elements.
Node 13095 belongs to maximum of 70 elements

Is there a limit to how large and complex a mesh can be before Elmer isn't able resolve it? I am able to open a smaller version of the mesh (~16MB) and run simulations without any issues. I am also able to convert it into an Elmer mesh using ElmerGrid as well.

[raback]

Hi,

How old is the ElmerGrid version? This should certainly not be too big. Maybe you can share a link to it.

-Peter

[kevinarden]

The output mentions only 203 elements, 3 noded beams, and 510 elements 10 noded tets. There are no boundary elements which would be 306, 6 noded triangles. I went to salome and purposely created such a mesh. Although not as large as yours.

Opening the unv in ElmerGUI, ElmerGUI recognizes there are no boundary face elements, and generates them using its meshing tool. Not so bad on my test model, but it would choke and crash, try to mesh a large complicated model.

Using ElmerGrid to convert the file, like your output doesn't report any errors. But there are mesh files generated. Loading this mesh into ElmerGUI shows nothing. It shows nothing because ElmerGUI uses the boundary elements to show the bodies. Without boundary elements nothing to show by default.
Going to view, checking volume elements on shows the volume elements, the body, that has no boundary elements.

This is my test unv.

testp.unv

(138.35 KiB) Downloaded 35 times

[Rich_B]

Hello,

Perhaps try to capture the output messages from ElmerGUI while opening the large unv file?

Open a command prompt in the case folder.
type in 'elmergui > log-elmergui.txt' and press enter.
ElmerGUI will start, so load the unv file. If the file loads successfully, just exit. If it doesn't load, then ElmerGUI will crash. Either way, the text file will capture the steps of the loading attempt.

Take a look at the text file for clues.

For an example, the log file when loading Kevin's sample unv file is attached.

Rich.

[thiennz]

Hi,

How old is the ElmerGrid version? This should certainly not be too big. Maybe you can share a link to it.

-Peter

I'm using what I believe is the latest version of Elmer downloaded from the ElmerFEM website (https://sourceforge.net/projects/elmerfem/).

Hello,

Perhaps try to capture the output messages from ElmerGUI while opening the large unv file?

Open a command prompt in the case folder.
type in 'elmergui > log-elmergui.txt' and press enter.
ElmerGUI will start, so load the unv file. If the file loads successfully, just exit. If it doesn't load, then ElmerGUI will crash. Either way, the text file will capture the steps of the loading attempt.

Take a look at the text file for clues.

For an example, the log file when loading Kevin's sample unv file is attached.

Rich.

I tried capturing the output messages from ElmerGUI but haven't gotten anything written in the file. When I attempt loading the .unv file, ElmerGUI will not respond for a few minutes before closing and leaves an empty .txt file with no output messages.

I was thinking it might have to do with how thin some of my features are. I am modelling some electrodes that are are on the order of 10 to 100mm in length and width but the thickness is 1um. I don't run into any errors meshing on SALOME with these dimensions but it's my guess as to what I might be running into the problems I have.

[kevinarden]

ElmerGUI recognizes there are no boundary face elements, and tries to generate the boundary elements using its meshing tool. However its meshing tool can not handle large complicated files.

[Rich_B]

Hello,

If you are running under Windows, the latest installer is located here:

https://www.nic.funet.fi/pub/sci/physics/elmer/bin/

The version on Sourceforge is over a year old, it would be good to install the latest version.

Also, the latest documentation is located here:

https://www.nic.funet.fi/pub/sci/physics/elmer/doc/

As Kevin mentioned, the meshing tool in ElmerGUI is old. It uses nglib from Netgen, but the version is quite old.

Rich.

[kevinarden]

It is possible to turn off the automesh feature in ElmerGUI so that it just loads the file without trying to do any meshing.