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Spurious Contact/ Incorrect Penetration detection #29777

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maxnezdyur opened this issue Jan 31, 2025 · 2 comments · May be fixed by #29802
Open

Spurious Contact/ Incorrect Penetration detection #29777

maxnezdyur opened this issue Jan 31, 2025 · 2 comments · May be fixed by #29802
Labels
P: normal A defect affecting operation with a low possibility of significantly affects. T: defect An anomaly, which is anything that deviates from expectations.

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@maxnezdyur
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Bug Description

Found example of spurious contact when working on explicit contact. MWE below shows incorrect penetration values.

Steps to Reproduce

[Problem]
  solve = false
[]
[Mesh]
  [block_one]
    type = GeneratedMeshGenerator
    dim = 3
    nx = 3
    ny = 3
    nz = 1
    xmin = 4.5
    xmax = 5.5
    ymin = 4.5
    ymax = 5.5
    zmin = 0.001
    zmax = 1.001
    boundary_name_prefix = 'ball'
    elem_type = TET4
  []
  [block_two]
    type = GeneratedMeshGenerator
    dim = 3
    nx = 10
    ny = 10
    nz = 1
    xmin = 3
    xmax = 7
    ymin = 3
    ymax = 7
    zmin = -2
    zmax = 0
    boundary_name_prefix = 'base'
    boundary_id_offset = 10
    elem_type = TET4
  []
  [block_one_id]
    type = SubdomainIDGenerator
    input = block_one
    subdomain_id = 1
  []
  [block_two_id]
    type = SubdomainIDGenerator
    input = block_two
    subdomain_id = 2
  []
  [combine]
    type = MeshCollectionGenerator
    inputs = ' block_one_id block_two_id'
  []
[]

[AuxVariables]
  [penetration]
    order = FIRST
    family = LAGRANGE
  []
  [closest_point_x]
    order = FIRST
    family = LAGRANGE
  []
  [closest_point_y]
    order = FIRST
    family = LAGRANGE
  []
  [closest_point_z]
    order = FIRST
    family = LAGRANGE
  []
[]

[AuxKernels]
  [penetrate]
    type = PenetrationAux
    variable = penetration
    boundary = base_front
    paired_boundary = ball_back
    quantity = distance
  []

  [penetrate11]
    type = PenetrationAux
    variable = closest_point_x
    boundary = base_front
    paired_boundary = ball_back
    quantity = closest_point_x
  []

  [penetrate13]
    type = PenetrationAux
    variable = closest_point_y
    boundary = base_front
    paired_boundary = ball_back
    quantity = closest_point_y
  []

  [penetrate15]
    type = PenetrationAux
    variable = closest_point_z
    boundary = base_front
    paired_boundary = ball_back
    quantity = closest_point_z
  []
[]

[Executioner]
  type = Steady

  solve_type = 'PJFNK'
[]

[Outputs]
  exodus = true
  execute_on = TIMESTEP_END
[]

Figure below is from running the above file.
Image

MWE came from work with explicit contact. Spurious contact below happened with a penalty node face method.
Image

Impact

Spurious contact prevents users from trusting results.

[Optional] Diagnostics

No response
@maxnezdyur maxnezdyur added P: normal A defect affecting operation with a low possibility of significantly affects. T: defect An anomaly, which is anything that deviates from expectations. labels Jan 31, 2025
@maxnezdyur
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@recuero
Do you know if the _closest_point in PenetrationInfo is always supposed to be on the face of the element that the node is using to compute its distance? PenetrationInfo doesn't have a lot of documentation, so having trouble finding what each of the members are supposed to be.

maxnezdyur added a commit to maxnezdyur/moose that referenced this issue Feb 3, 2025
@maxnezdyur
fix tang check (idaholab#29777)
77ebc15
@maxnezdyur maxnezdyur linked a pull request Feb 3, 2025 that will close this issue
Open
maxnezdyur added a commit to maxnezdyur/moose that referenced this issue Feb 3, 2025
@maxnezdyur
fix tang check (idaholab#29777)
d572a3b
@recuero
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recuero commented Feb 4, 2025

It's supposed to as far as I recall. There may be an issue with tets and close projections. I think I ran into something like this years ago.

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P: normal A defect affecting operation with a low possibility of significantly affects. T: defect An anomaly, which is anything that deviates from expectations.
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Check tangential tolerances in PenetrationThread maxnezdyur/moose
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@recuero @maxnezdyur