Hello all,
I’m using Coreform Cubit 2020.2 on Windows 10.
I would like to create a smooth fillet between two adjacent cylinders that touch at one point. Is there a series of commands that can achieve this? I don’t see a fillet option and would eventually like to automate fillet creation of different radii with Python. Thank you for your time and please let me know if I can provide further information.
David H.
Fillets are called “blends” in Cubit, and are applied to curves that join surfaces. The command is:
Modify Curve <id_list> {Blend|Chamfer} Radius <value>
And can be found in the GUI
Here’s an example journal file
reset
cylinder r 1 height 4
cylinder r .75 height 4
rotate Volume 2 angle 90 about Y include_merged
unite vol all
modify curve 6 5 blend radius .1
Before:
After:
Hi Greg,
Thank you for the information. I am attempting to blend two parallel, tangent cylinders like the picture below.
The curve that is shared between the two cylinders is non-manifold. The topology is the same as two cubes connected by a single curve. Which of the four surfaces connected at the curve define the fillet?
The best I can do in this situation is fall back to manual construction.
reset
create cylinder radius 1 z 10
volume 1 copy move x 2
unite volume all
create cylinder radius .5 z 10
volume 3 move x 1
compress
create vertex AtIntersection curve 7 5
create vertex AtIntersection curve 7 2
create curve location vertex 5 direction on surface 4 at location vertex 5 length 1
create curve location vertex 7 direction on surface 1 at location vertex 7 length 1
create vertex AtIntersection curve 8 9
create surface circle center vertex 11 5 7
webcut body 2 sweep surface 10 perpendicular outward through_all
delete volume 4
body 3 move y -{2*Vy(11)}
webcut body 2 sweep surface 10 perpendicular outward through_all
delete volume 5
delete body 3
delete curve all
delete vertex all
unite body all
Karl
One option would be to move the cylinders so that they just barely overlap, and are thus manifold:
reset
create cylinder radius 1 z 10
volume 1 copy move x 1.99999
unite vol all
modify curve 5 7 blend radius .25
After unite:
Zooming in:
After blend:
Another option is to make the cylinders just barely larger for the same purpose
reset
create cylinder radius 1.00001 z 10
volume 1 copy move x 2
unite vol all
modify curve 5 7 blend radius .25
Then, if it really matters, you could “undo” the slightly larger cylinders by using offset surfaces to create slightly smaller cylinders:
create sheet offset from surface 12 11 9 7 offset -0.00001
create surface curve 25 26 29 21
create surface curve 23 19 30 27
stitch body 3 4 5
delete vol 1
compress