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[Jan Stránský <question669827@xxxxxxxxxxxxxxxxxxxxx>]

Question #669827 on Yade changed:
https://answers.launchpad.net/yade/+question/669827

    Status: Open => Answered

Jan Stránský proposed the following answer:
Hello,

> I see their contact is point-point

always try to get also some numerical evidence. E.g. if you print the
i.geom.penetrationDepth, it should be some positive value, corresponding
to face (maybe a "little", but not exactly point-point)

1. yes, just try to make the force 10x, 100x, 1000x ... higher

2. yes, of course, the amount of deformation depends on stress/forces
values

3. I am most familiar with CpmMat, but other materials can be used, too. An example of a ball composed by overlapping smaller spheres:
###
from yade import pack
# initial packing and a wall
R = 1.
r = .2
mat = CpmMat(young=1e6,poisson=.2,sigmaT=1e20,epsCrackOnset=1e20,relDuctility=2) # a cohesive elastic material
O.materials.append(mat)
sphs = pack.regularHexa(pack.inSphere((0,0,0),R),r,-.6*r) # -.6r = to create overlaps
O.bodies.append(sphs)
O.bodies.append(wall((0,0,-2*R),2))
O.engines = [
  ForceResetter(),
  InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Wall_Aabb()]),
  InteractionLoop(
    [Ig2_Sphere_Sphere_ScGeom(), Ig2_Wall_Sphere_ScGeom()],
    [Ip2_CpmMat_CpmMat_CpmPhys()],
    [Law2_ScGeom_CpmPhys_Cpm()],
  ),
  NewtonIntegrator(damping=.1,gravity=(0,0,-9.81)),
]
O.dt = 0.
# O.step() creates initial cohesive interactions with defined stiffness.
# Further material change does not influence existing interactions
O.step()
#
mat.young = 1e10 # increase stiffness for new contacts
O.dt = PWaveTimeStep()
###

cheers
Jan

PS: until now your description is about elastic behavior, please
consider to modify the title of the question

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