I’m interested in 3D setups with multiple adjacent parts with different materials, so as a simple preliminary demonstration task I have a pair of concentric, adjoining cylinders. I figured I’d have to remove duplicate nodes while keeping the different material regions as separate blocks. I noticed in the “Merge Nodes” documentation that you have to be careful doing this, which I presume means you can screw up information related to associated blocks or other data structures.
How do you do this? That is, how do you remove overlapping nodes, keeping the blocks separate for assignment as different material regions. Do I need to remove the duplicate nodes, even if I’m not using that as a slip surface?
To ensure adjacent volumes share nodes, just make sure you use the “imprint” and “merge” commands after creating your geometry. This has the effect of sharing surfaces where the volumes meet. Only one set of nodes will be generated on the shared surfaces. To ensure you have a slip connection, just make sure you do not use the “merge” command.
The first example generates a contiguous mesh
reset
Cylinder rad 5 height 10
Cylinder rad 4 height 10
Subtract vol 2 from vol 1 keep
Delete vol 1
Merge all
Mesh vol all
The second example generates a slip/contact interface
reset
Cylinder rad 5 height 10
Cylinder rad 4 height 10
Subtract vol 2 from vol 1 keep
Delete vol 1
Mesh vol all
To be sure you can use the following command to see where the coincident nodes are (2 nodes created at the same location)
topology check coincident node node all tolerance 1.0e-6 draw
