Copy mesh with surfaces issue

Coreform Cubit Meshing
#1

Hello.

The image included shows the surface I have imported in orange (vertices > curves > surface) and behind that surface is an identical surface in blue.

I am attempting to copy the mesh from one surface to another identical surface by exporting the unmeshed surface then importing that surface and then meshing it, then I am using the ‘copy mesh’ functionality to create mesh on the 2nd imported surface.
The problem is these artifacts in Blue between the two sides of the orange surface walls (a “v-shaped” geometry). To my eye, it appears that Trelis is having difficulty in picking points in the mesh to copy and it jumps from one side of the surface to the other. Any help is much appreciated.

image
image355×537 53.5 KB

#2

Hello @bwtco8!

That certainly doesn’t look right! Would you be able to provide a Trelis file of this problem so I can look into this in more detail?

#3

Sure, @gvernon.
ashare.trelis (648.1 KB)

I have set up the geometry and imported it again (so there are 2 identical surfaces in the workspace), and am leaving them unmeshed.

The commands below give the same result:
volume all size {dx}
volume all scheme tetmesh
mesh surface 1
copy mesh surface 1 onto surface 2 source curve 1 source vertex 1 target curve 5 target vertex 5

I hope it’s manageable.

#4

So there definitely is something off with the copy mesh command, if I had to guess off-the-cuff I’d say it’s probably because of high curvatures in the spline surface and roundoff issues… I’ll log an issue to look into this.

Good news is that, for this Trelis file, there is a workaround (which also happens to be the preferable approach). You want to imprint the surfaces on each other, but not merge them. Here’s a journal file for inspiration:

## Original approach
#{dx=1}
surf all size {dx}
surf all scheme trimesh
mesh surface 1
draw surface 1

## This method doesn't work
copy mesh surface 1 onto  surface 2 source curve 3  source vertex 3  target curve 7  target vertex 7  
draw surface 2

## Instead, let's to an "imprint"
delete mesh
imprint surface 1 2
surf all scheme trimesh

## We could mesh both at same time, but lets mesh one at a time for dramatic effect
mesh surface 1
draw surface 1

mesh surface 2
draw surface 2
#5

Good going! I had an old line of code I was using that had imprint but also merge, I hadn’t though of removing the merge. Thanks for you help.

#6

So in continuation of this thread, I am trying to surround those two surfaces above (let’s call them slabs) with a brick and then mesh it all and create nodes.

I have it set so the brick is flush with the top and bottom of those slabs in the z-plane.

I’m trying to separate element connectivity in the two sets of surfaces above (essentially to track as one surface moves one way and the duplicate meshed surface in the other), and I want the mesh of the brick to be enhanced around areas where it interacts with these slabs.

I also need the Surface meshes of the slabs to be consistent with the Volume mesh of the brick, and to be identical along slabs.

I’ve been experimenting more with Merge and imprint.

Recently, I tried importing the slab geometries, then imported the brick (block), then merged / imprinted and meshed the volume (merging is allowing the brick mesh enhancement along slab interactions), and then unmerged (deleted the slab meshes created here - then created the slab meshes as above with imprint) and set up nodes. I am noticing differences in nodes, that is they are not co-located between the volume mesh and that of the two identical pairs of surfaces.
image

The three nodes above are for the fault pairs, very close to them are the Volume mesh nodes. They are not identical though. That’s what’s I’m trying to achieve here…