Webcut failed for volume with nonplanar sheet

Dear everyone,

I am trying to cut the volume with a nonplanar sheet but it is failed. I have tried to read other problems in this forum but it is still not fixed.

I get an error notification as follow:

Cubit>webcut volume v_domain with sheet surface s_topo

Performing webcut operation…

Preserving undo information…done

ERROR: /home/umarf/Documents/Alvina/mesh/mesh big/cggv20_geometri_cubit_body_fix.jou (69). Error in webcutting volume with sheet.

ERROR: /home/umarf/Documents/Alvina/mesh/mesh big/cggv20_geometri_cubit_body_fix.jou (69). ACIS API error number 21040

ACIS API message = internal inconsistency in boolean operation

No volumes were webcut.

How can I solve this problem?

Thank you for your assistance.


-Alvina K K

How did you define the surface?
The cutter has exhibited wonky issues for me cutting complex volumes with complex surfaces.

I find the loop tool and loft tool are limited in their handling of complex/natural curves and defining sheets based on them.

One solution that has been robust for me is if you can build a volume incorporating your cutting surface. If you can build a solid volume the program seems to then be able to handle the cutting operation without issue (I’m guessing the volume-volume intersection testing is more robust/less path dependent).

Thank you for your reply.

I choose low opacity option (for visualization) only to show that the surface is lying inside the volume. The volume is actualy solid. But the sheet failed to cut the volume.

-Alvina K K

Right, I figured you’re tying to cut the solid with a sheet body.

What I am suggesting is to build a solid from that sheet body (ie a simple projection ‘vertically’).

Then once that sheet body is part of a new solid, go back and cut your original solid with the face of the ‘new’ solid.

Given the simple example you’re showing I’m assuming you’re trying to cut a complex solid with a complex surface.
My suggestion comes from trying to do blade grid blocking in Coreform. The above method allowed me to be partially successful before giving up and doing the blocking in my CAD program.

Bon chance.

Daniel

Dear Daniel,

Thank you for your advice.

“Given the simple example you’re showing I’m assuming you’re trying to cut a complex solid with a complex surface”
Yes, you are right.

I would like to clarify some parts,

"What I am suggesting is to build a solid from that sheet body (ie a simple projection ‘vertically’).

I never try to use projection. Do you mean that it is like the “sweep” command?

Then once that sheet body is part of a new solid, go back and cut your original solid with the face of the ‘new’ solid."

So it means that the main volume will be cut by the new volume?

Thank you in advance.

-Alvina

Hi @alvinakk,

Can you reply with a “minimum working example” journal script that replicates this error? Or, if you can’t provide the journal file (i.e. can’t send an imported geometry file) could you instead provide a stripped down Cubit file that replicates the error? For example, you could delete all the volumes except for the culprit volume and surface.

Have you tried the sheet extended from surface or tool webcuts? e.g.

reset
bri x 1
create vertex -.75 -.75 -.25 
create vertex .75 -.75 .25 
create vertex .75 .75 0 
create vertex -.75 .75 .2 
create curve polyline vertex 10 11 12 9 10
create surface curve 15 16 13 14  
webcut volume 1  with sheet extended from surface 7  
reset
bri x 1
create vertex -.75 -.75 -.25 
create vertex .75 -.75 .25 
create vertex .75 .75 0 
create vertex -.75 .75 .2 
create curve polyline vertex 10 11 12 9 10
create surface curve 15 16 13 14  
webcut Volume 1  tool Body 2  

It is true that very complicated surfaces and/or very nasty geometry can cause even these methods to fail, which is why it would be helpful to see your specific problem, but let’s try this out first.

I have tried your suggestions but it does not work.

With the extended sheet :
Cubit>webcut volume v_domain with sheet extended from surface s_topo

Performing webcut operation…

  • if the surface to extend is a spline surface,*
    it may not extend far enough to cut the volume.
    Preserving undo information…done
    ERROR: /home/umarf/Documents/Alvina/mesh/mesh big/cggv20_geometri_cubit_body_fix.jou (69). Unable to extend spline surface
    WARNING: A cutting sheet could not be made that
  •     intersects the bodies to be webcut.*
    

No volumes were webcut.

With tool body :
webcut Volume v_domain tool Body b_topo

Performing webcut operation…

Preserving undo information…done

ERROR: /home/umarf/Documents/Alvina/mesh/mesh big/cggv20_geometri_cubit_body_fix.jou (70). Error in webcutting volume with sheet.

ERROR: /home/umarf/Documents/Alvina/mesh/mesh big/cggv20_geometri_cubit_body_fix.jou (70). ACIS API error number 21040

ACIS API message = internal inconsistency in boolean operation

No volumes were webcut.

Please find here the attachment for the jou file.alvina_problem.tar.gz (583.7 KB)

Thank you for your assistance.
-Alvina