Importing from Solidworks IGES with Mesh Problems

Chris

I drew several surfaces in Solidworks and imported to Mecway as an IGES file (both attached). Every time I generate a mesh, the perpendicular interfaces do not generate nodes at the same locations, and the surfaces cannot connect. My questions are below. Knitting the surfaces in Solidworks didn't resolve the issue, and introduced many skewed elements.

What can I do in Solidworks to get these surfaces joined and automatically mesh nicely in Mecway?
What could Mecway do to mesh this IGES file differently and connect the perpendicular surfaces? Bonded contacts might function, but would seem to alter the stiffness matrix.
Any other suggestions?

Thanks,

Chris

Victor

All IGES files have this problem with Mecway. Please use STEP instead. IGES support is only really there for very old CAD software that somehow doesn't export STEP. I might remove that in future versions.

Chris

I saved thee same Solidworks part as a STEP file, but i get the same result. Do you have any other suggestions?

Thank you,

Chris

disla

¿Have you tried to create a unique component (surface) before exporting (Insert > Surface > Knit.)?.
Salome has some free tools to build such a unique component.

Sergio

As is a relatively simple geometry, I would work with a solid mesh. I'm not sure how must be treated the unions between two crossing surfaces using shells.

Anyway, as Disla says, with Salome you can join the surfaces and create a mesh with coincident nodes at the intersections. If you want to upload the stps/igs I could make a try, looks like an interesting problem to solve.

Chris

Thanks for your input. I tried to upload the STEP file for Sergio's review, but it could not complete the upload for several hours. I emailed it direct for assistance.

I do not have Salome on my machine, but will try to load it for Windows. I tried to knit the surface in Solidworks, but it did not actually join the perpendicular surfaces.

Question, with a solid mesh, how could I generate brick or shell elements for these thin surfaces? When I have tried "surface mesh" on a solid, get a shell that surrounds the solid.

Thanks again,

Chris

Victor

You could try to use an actual solid mesh made from tet10 elements. You might need more than one element in the thickness direction for good accuracy but since it's fairly simple, you might get by without having too many elements.

Sometimes you can use the Surface mesh option like you did then delete the extra surfaces leaving just one for each plate then set a Shell offset to compensate for the half-thickness. However, in this case, the intersections still won't be connected properly.

If it was me, I'd probably make it by hand in Mecway. Starting with two curved lines, then extrude everything else off them as well as using some Mesh tools -> Create -> Element and Refine -> Custom. I began that in the attachment. There's fair bit of labor there though so only if you can't get any CAD software to do it.

Sergio

This the model meshed with coincidents nodes in Salome, now I would like to see the results!

Chris

Sergio - Thanks, the model was able to run modals with a couple element adjustments from tri3 to quad8. Did you use Salome, or something else?

Victor, thanks for your suggestion and start of a model from scratch. I was hoping to avoid building it all in Mecway, but realize that it is possible.

Thanks again for your help,

Chris

Sergio

I have done the mesh in Salome. Just explode all the surfaces, then join again to make the mesh coincident at the intersections. There was one horizontal surface that was not exploded, so I divide it using the vertical ones.

Chris

Sergio and Victor,

I still have more details to add to the model, but the attached is where I am going with it. I was not able to get Salome loaded, so I started manually building the model from my existing node locations.

I had difficulties extruding the shells into bricks at the connection points. It seems like I would need to nearly rebuild the model for brick based approach. Do you have any thoughts on making these connections with less effort?

My first goal is to get modes from the model, and then to look at stress as a result of some applied forces.

Thanks again for your help,

Chris

Victor

You could make it double thickness by extruding from both sides of each surface as shown in the attached picture. The corner nodes will end up a bit out of place so you'd have to reposition them manually.

It should work pretty well using shells though.

Beware that this mesh has a lot of incompatible connections between elements so it won't work correctly. It looks like you might have refined some parts while they weren't connected to other parts. There should be no joints like the ones circled in the other attached picture. If you use View -> Open cracks, you can see the elements come apart where they're not properly connected.