New Neper command to cut a tessellation by a rounded cube

[rquey]

Neper (version 4.8.2-1) now has a -transform "cut(cube(...))" option that cuts a tessellation by a cube with rounded corners. This can be used, for instance, to model tensile specimens with flat edges and rounded shoulders:

neper -T -n 1000 -morpho gg -morphooptistop "val=1e-2" -domain "cube(1,0.2,4)" -transform "cut(cube(-10,0.25,-10,10,1,3,0.27),cube(0.75,10,-10,10,1,3,0.27))" -reg 1                                                                                          
neper -M n1000-id1.tess -rcl 0.8
neper -V n1000-id1.tess,n1000-id1.msh -dataedgerad "((domtype==1)?0.006:0.004)" -showelt1d all -dataelt1drad "((domtype==1)?0.006:0.004)" -dataelt3dedgerad 0.001 -imagesize 500:1000 -cameraangle 8.5 -showtess 1 -showmesh 0 -print tess -showtess 0 -showmesh 1 -print mesh
convert +append tess.png mesh.png tess-mesh.png

As cutting in "experimental" (i.e., not 100% stable), it may fail sometimes. In such cases, increasing -n of changing -id can help.

[charanjo]

Hi, Can a cylindrical torsion specimen be created like this?

[Zdmire]

Hi, thanks for your sharing. However, i encountered a problem when i tried to cut a tessellation by a round cube in 2D. There were always errors, so following your instructions, I increased the number of -n and was able to successfully divide it. However, a new problem emerged. The grains at the division boundary became distorted and formed very large grains. How can we improve this step?. I haven't been able to solve this kind of cutting problem in 2D for several days. @rquey Could you help me?

neper -T -n 2000 -morpho gg -morphooptistop "val=1e-2" -domain "square(1,4)" -transform "cut(cube(0.45,0.55
,-2,2,-3,3,0.27))" -dim 2 -reg 1

neper -V n2000-id1.tess -datacellcol id -imagesize 1200:1200 -print img