MultiPointContact: The skip-argument is ignored

[adtzlr]

add a test to verify the results.

Example

import felupe as fem
import numpy as np

mesh = fem.Cube(n=6)
mesh.update(points=np.vstack([mesh.points, [1.1, 0, 0]]))
region = fem.RegionHexahedron(mesh)
field = fem.FieldContainer([fem.Field(region, dim=3)])

boundaries = fem.dof.symmetry(field[0])
boundaries["move"] = fem.Boundary(field[0], fx=1.1, skip=(0, 1, 1))
boundaries["control-y"] = fem.Boundary(field[0], fx=1.1, skip=(1, 0, 1))
boundaries["control-z"] = fem.Boundary(field[0], fx=1.1, skip=(1, 1, 0))

umat = fem.NeoHooke(mu=1, bulk=2)
solid = fem.SolidBody(umat=umat, field=field)
right = np.arange(mesh.npoints)[mesh.x == 1]
plate = fem.MultiPointContact(field, points=right, centerpoint=-1, skip=(0, 0, 0))

move = fem.math.linsteps([0, -0.3], num=3)
ramp = {boundaries["move"]: move}
step = fem.Step(items=[solid, plate], ramp=ramp, boundaries=boundaries)

job = fem.Job(steps=[step])
job.evaluate()

ax = solid.imshow("Principal Values of Cauchy Stress")

[adtzlr]

skip behaves differently in MPC and its contact variant. In the contact mode, skip means not considered detection directions. The contact itself is always frictionless.

[adtzlr]

That example should be added to the docs.