MESHING 3D VOLUME

Hoi Borja

oeps, fjooeeoeo.
No, it did not check your problem. I rarely use step and iges files to read into Salome.
And I nearly always use netgen123 to mesh my constructions. Just because it is easy most of the time. Though whether this is useful for this stp/igs problem I cannot say of course.
But for once, tomorrow *) I *will* have a look at your step and iges files. So if you can bear at least one more night ....?
But maybe Claus will try tonight.

*) Tomorrow I will first install Ubuntu 10.04. So I probably have some issues for the rest of the month. So if you donot here from me the next couple of days, it is a non-operational pc. Unless someone convinces me not to upgrade, like eg:

caelinux.com/CMS/index.php?option=com_jo...=6&limitstart=24
or
caelinux.com/CMS/index.php?option=com_jo...&id=4161#msg4161

kind regard - kees<br /><br />Post edited by: Kees Wouters, at: 2010/04/30 00:19

Borja AP wrote:

Hi every body.

Is it possible that I am the unique person who experienced that problem with iges or step importation??

Come on Kees/Claus you may have some experience on it...

I am a Naval Architect and I will allways do the hull forms on specialized Naval Architecture Software so I'll allways deal with step or iges importation into salome.

Regards.


Salome-Meca_2009GPL
Salome v.4.1.4

Okay, so I played around with the bracket a bit while watching a horrible movie (The Happening, don't watch it) and my conclusion is that the netgen (with quads) is simply too flimsy to work with extrusion 3D.

I can get a pretty decent quality mesh by doing the following:
All the sides that has a normal parallel to XY plane i.e. the small faces incl. the holes are grouped and meshed with quads (as submesh). The two big surfaces are meshed with 2D tets and have 3D extrusion set for volume meshing.
That gives a reasonable mesh - combined with 'quadratic' i.e. 2nd order elements, it should be okay.

Another way, which is probably the easiest way now that I think about it, is to extrude one of the big surfaces after meshing it with netgen 2D-1D. Create a group on the lower big surface, select the group and create a new mesh (you can only select 2D now), define it as 2D-1D netgen with quads. Mesh it. Select the mesh and click extrude in the tool bar, tag 'select whole mesh/submesh' and select how many steps the extrusion should take, devide the Z-distance with this: 4 extrusion steps = Z-height of 0.0025 because you'd want a result of 0.01. Don't forget to switch to 'faces' instead of 'elements' in to top of the window, otherwise you'll just get a hollow shell.

In attachment: left is done with the first method, right, the second.

Note: Meshing on the Linux platform is shite atm., I can't find a good free mesher that'll create quality quad/hexa mesh - Salomé is actually the best one available, 'cept LS-DYNAs prepost, but that doesn't export the mesh, sadly.

I'll stop typing now.

Edit: to answer your question:

So, my question is, is it possible to set a Default Tolerance/Precision in the geometry module instead of 1e-7 which comes by default??

No, or I don't know how to at least.<br /><br />Post edited by: Claus, at: 2010/04/30 02:11