We’ve got permission from a user to post this question about quad meshing and the desired refinement.
The user ended up with a mesh as seen in the upper representation but desired was the lower representation.
The base journal file of the problem.
forum_desired_refinement.jou (5.5 KB)
@karl did a great job showing a couple of ways to get a good refinement. So i will repeat his answer.
The quad refinement is a 1-to-2 element refinement, so while you can refine that way it will not give you the exact pattern you want, but it may be sufficient.
delete mesh
reset surface all
surface all size .02
mesh surface all # This gives a uniform mesh over all surfaces.
refine surface 3 4 numsplit 1 bias 1 depth 1
This gives four elements instead of 3 across the layers. Note that in the GUI I had to click the smooth option off.
Hex elements have the desired 1-to-3 refinement pattern. We can get the desired mesh by refining hexahedra and exporting only the surface mesh.
del mesh
regularize surface 6 7 # get rid of some construction curves
sweep surface all perpendicular distance .02 switchside .02
compress
imprint all
merge all
reset vol all
Curve 8 interval 1
Curve 6 interval 1
Curve 5 interval 1
Curve 1 interval 4
Curve 4 interval 3
Curve 30 interval 2
mesh vol all
# only select the interior hexes so the bias doesn't propagate too far.
refine hex in volume 3 4 numsplit 1 bias 1 depth 0 # again make sure the smooth option is off and the depth is set to 0
# create an element block to export only the quads
block 1 surface 1 to 8 # create blocks as needed for your material types.
export mesh 'refined_quads.exo'
Finally, we can get exactly the mesh you desired by inserting geometric constraints on the mesh. The paver will insert the 1-to-3 pattern in a single surface. We must set those surfaces to scheme pave.
del mesh
split surface 6 through vertex 71 44
split surface 10 through vertex 41 68
split surface 11 through vertex 38 14
Curve 12 copy move y -.02
create vertex on curve 51 47 segment 4
imprint volume 2 with curve 51
imprint volume 2 5 with vertex 97 99 98 101 100 102
split surface 5 skew
split surface 16 skew
imprint volume 2 with curve 51
del vert all
del curve all
imprint all
merge all
Surface 20 17 18 19 12 14 24 22 21 23 scheme pave
Curve 28 interval 3
mesh surf all
