XFEM Failure Analysis Report

Introduction

The FAR for the XFEM module describes the system functional and non-functional requirements that describe the expected interactions that the software shall provide.

Dependencies

The XFEM module is developed using MOOSE and can itself be based on various MOOSE modules, as such the FAR for the XFEM module is dependent upon the following documents.

Framework Failure Analysis Report
sqa/tensor_mechanics_far.md

Failure Analysis Requirements

The following is a complete list for all the requirements related to failure analysis for the XFEM module.

xfem: Mesh Cut 2D Fracture
23.9.1
The XFEM module shall represent a propagating crack in a 2D mechanics model with XFEM, where the crack is defined using a topologically defined surface cutting mesh by MeshCut2DFunctionUserObject
1. and crack growth and direction is computed by a fracture integral with constant fracture toughness.
2. and crack growth and direction is computed by a fracture integral with fracture toughness sampled from a material at the crack tip.
3. and crack growth is a maximum stress criterion and the growth direction is in the original crack direction.
4. and crack growth and direction is computed by a fracture integral with constant fracture toughness or maximum stress criterion.
5. and produce an error when fracture toughness is specified by more than one input source.
6. and crack growth is defined by a function. The average crack tip stress changes with crack orientation and properly accounts volume averaging near surfaces.
Specification(s): 2D/k_growth, 2D/kvpp_growth, 2D/stress_growth, 2D/k_stress_growth, 2D/k_error, 2D/stress_check
Design: MeshCut2DFunctionUserObject
Issue(s): #23572 #27659 #32418
Collection(s): FUNCTIONALFAILURE_ANALYSIS
Type(s): CSVDiffRunExceptionExodiff

xfem: Nucleation Uo
23.12.4The system shall error if the nucleation length is smaller than the element being cut.
Specification(s): errorSmallCut
Design: MeshCut2DRankTwoTensorNucleation
Issue(s): #27054
Collection(s): FUNCTIONALFAILURE_ANALYSIS
Type(s): RunException

xfem: Solid Mechanics Basic
23.17.5
The XFEM module shall represent a propagating crack in a 3D mechanics model with XFEM, where the crack is defined using a topological surface cutting mesh by CrackMeshCut3DUserObject and allowed to propagate with
1. growth speeds determined by the fatigue cracking Paris law, or
2. growth speeds determined by the stress corrosion cracking constant timestep, or
3. growth speeds determined by the stress corrosion cracking maximum growth length, or
4. growth directions determined by computing the maximum hoop stress law using interaction integrals, or
5. growth directions determined by an parsed function, or
6. error when the number of points on the cutter mesh do not match the number of points in the DomainIntegralAction, or
7. properly moving crack front nodes using the maximum hoop stress growth direction, or
8. properly moving crack front nodes using SCC-driven non-uniform growth, or
9. properly moving crack front nodes for a corner crack using SCC-driven non-uniform growth, or
10. properly refining surface cutting crack front if crack front refinement occurs inside volume, or
11. not refining surface cutting crack front if crack front refinement would occur outside volume, or
12. without producing degenerate crack face elements with a prescribed function growth direction, or
13. growing the crack front and double cutting a volume element edge, or
14. keeping the crack front on the free surface when the crack front grows into a corner on the volume, or
15. keeping the crack front on a concave-up curved volume surface, or
16. keeping the crack front on a concave-down curved volume surface, or
17. keeping the crack front consistent on a concave-up curved volume surface under the maximum hoop stress growth direction, or
18. growing a tilted crack through a tetrahedral volume when two geometric cut surfaces place their intersections on the same fragment face in a single growth step.
Specification(s): mesh_cutter_3d/fatigue, mesh_cutter_3d/scc_parseVec, mesh_cutter_3d/scc_reporter, mesh_cutter_3d/mhs, mesh_cutter_3d/function, mesh_cutter_3d/num_points_error, mesh_cutter_3d/face_cut_mid_hoopStress, mesh_cutter_3d/face_cut_mid_scc, mesh_cutter_3d/face_cut_corner_scc, mesh_cutter_3d/inactive_refine, mesh_cutter_3d/inactive_no_refine, mesh_cutter_3d/face_cut_mid_function, mesh_cutter_3d/double_cut_edge, mesh_cutter_3d/tet_hit_corner, mesh_cutter_3d/tet_concave_up, mesh_cutter_3d/tet_concave_down, mesh_cutter_3d/tet_concave_up_hoopStress, mesh_cutter_3d/tet_block_tilt_14
Design: CrackMeshCut3DUserObject ParsedVectorReporter StressCorrosionCrackingExponential
Issue(s): #6320 #23572 #32418 #32779
Collection(s): FUNCTIONALFAILURE_ANALYSIS
Type(s): RunExceptionCSVDiffExodiffJSONDiff


[k_growth]
  type = Exodiff
  input = 'edge_crack_2d_propagation.i kcrit_based_meshCut_uo.i'
  exodiff = 'kcrit_based_meshCut_uo_xfemcutter_XFEMCutMeshOutput.e-s0004'
  abs_zero = 1e-8
  map = false
  # XFEM requires --enable-unique-ids in libmesh
  capabilities = 'unique_id'
  detail = ' and crack growth and direction is computed by a fracture integral with constant fracture toughness.'
[]


[kvpp_growth]
  type = Exodiff
  input = 'edge_crack_2d_propagation.i kvpp_based_meshCut_uo.i'
  exodiff = 'kvpp_based_meshCut_uo_xfemcutter_XFEMCutMeshOutput.e-s0004'
  abs_zero = 1e-8
  map = false
  # XFEM requires --enable-unique-ids in libmesh
  capabilities = 'unique_id'
  detail = ' and crack growth and direction is computed by a fracture integral with fracture toughness sampled from a material at the crack tip.'
[]


[stress_growth]
  type = Exodiff
  input = 'edge_crack_2d_propagation.i stress_based_meshCut_uo.i'
  exodiff = 'stress_based_meshCut_uo_xfemcutter_XFEMCutMeshOutput.e-s0004'
  abs_zero = 1e-8
  map = false
  # XFEM requires --enable-unique-ids in libmesh
  capabilities = 'unique_id'
  detail = ' and crack growth is a maximum stress criterion and the growth direction is in the original crack direction.'
[]


[k_stress_growth]
  type = Exodiff
  input = 'edge_crack_2d_propagation.i kcrit_stress_based_meshCut_uo.i'
  exodiff = 'kcrit_stress_based_meshCut_uo_xfemcutter_XFEMCutMeshOutput.e-s0004'
  abs_zero = 1e-8
  map = false
  # XFEM requires --enable-unique-ids in libmesh
  capabilities = 'unique_id'
  detail = ' and crack growth and direction is computed by a fracture integral with constant fracture toughness or maximum stress criterion.'
[]


[k_error]
  type = 'RunException'
  input = 'edge_crack_2d_propagation.i kvpp_based_meshCut_uo.i'
  cli_args = "UserObjects/cut_mesh2/k_critical=100"
  expect_err = 'Fracture toughness cannot be specified by both k_critical and k_critical_vectorpostprocessor.'
  detail = ' and produce an error when fracture toughness is specified by more than one input source.'
[]


[stress_check]
  type = CSVDiff
  input = crack_front_stress_function_growth.i
  csvdiff = 'stress_check_CrackFrontNonlocalStress_0001.csv stress_check_CrackFrontNonlocalStress_0002.csv stress_check_CrackFrontNonlocalStress_0003.csv stress_check_CrackFrontNonlocalStress_0004.csv'
  # XFEM requires --enable-unique-ids in libmesh
  capabilities = 'unique_id'
  detail = ' and crack growth is defined by a function.  The average crack tip stress changes with crack orientation and properly accounts volume averaging near surfaces.'
[]


[errorSmallCut]
  issues = '#27054'
  type = RunException
  input = nucleate_bulkCrack.i
  cli_args = 'UserObjects/nucleate/nucleation_length=.001'
  expect_err = 'Trying to nucleate crack smaller than element length'
  # XFEM requires --enable-unique-ids in libmesh
  capabilities = 'unique_id'
  requirement = 'The system shall error if the nucleation length is smaller than the element being cut.'
[]


[fatigue]
  type = Exodiff
  input = 'edge_crack_3d_domain.i edge_crack_3d_fatigue.i'
  exodiff = 'edge_crack_3d_fatigue_out.e-s002'
  abs_zero = 1e-8
  map = false
  capabilities = 'unique_id'
  detail = ' growth speeds determined by the fatigue cracking Paris law, or'
[]


[scc_parseVec]
  type = CSVDiff
  cli_args = 'Executioner/end_time=11'
  input = 'edge_crack_3d_domain.i edge_crack_3d_scc.i'
  csvdiff = 'edge_crack_3d_scc_out_II_KI_1_0012.csv'
  capabilities = 'unique_id'
  detail = ' growth speeds determined by the stress corrosion cracking constant timestep, or'
[]


[scc_reporter]
  type = JSONDiff
  cli_args = 'Executioner/end_time=2'
  input = 'edge_crack_3d_domain.i edge_crack_3d_scc_crit.i'
  jsondiff = 'edge_crack_3d_scc_crit_out.json'
  capabilities = 'unique_id'
  detail = ' growth speeds determined by the stress corrosion cracking maximum growth length, or'
[]


[mhs]
  type = Exodiff
  input = 'edge_crack_3d_domain.i edge_crack_3d_mhs.i'
  exodiff = 'edge_crack_3d_mhs_out.e-s003 edge_crack_3d_mhs_out_XFEMCutMeshOutput.e-s0004'
  abs_zero = 1e-4 #crack face is normal to z so this gets rid of exodiffs caused by z-direction variables
  map = false
  partial = true
  capabilities = 'unique_id'
  detail = ' growth directions determined by computing the maximum hoop stress law using interaction integrals, or'
[]


[function]
  type = Exodiff
  input = 'edge_crack_3d_domain.i edge_crack_3d_propagation.i'
  exodiff = 'edge_crack_3d_propagation_out.e edge_crack_3d_propagation_out.e-s002'
  abs_zero = 1e-8
  map = false
  capabilities = 'unique_id'
  detail = ' growth directions determined by an parsed function, or'
[]


[num_points_error]
  type = RunException
  input = 'edge_crack_3d_domain.i edge_crack_3d_mhs.i'
  cli_args = 'DomainIntegral/number_points_from_provider=3'
  expect_err = 'This must match the number of points provided by the XFEM mesh cutter object.'
  capabilities = 'unique_id'
  detail = ' error when the number of points on the cutter mesh do not match the number of points in the DomainIntegralAction, or'
[]


[face_cut_mid_hoopStress]
  type = Exodiff
  input = 'face_crack_3d_domain.i face_crack_3d_xfem_hoopStress.i'
  cli_args = 'fname=hex_block'
  exodiff = 'face_crack_hoopStress_off_0_spin_0_XFEMCutMeshOutput.e'
  map = true # only matching cutter mesh, not xfem volume mesh
  capabilities = 'unique_id'
  detail = ' properly moving crack front nodes using the maximum hoop stress growth direction, or'
[]


[face_cut_mid_scc]
  type = Exodiff
  input = 'face_crack_3d_domain.i face_crack_3d_xfem_scc.i'
  cli_args = 'fname=hex_block'
  exodiff = 'face_crack_scc_off_0_spin_0_XFEMCutMeshOutput.e'
  map = true # only matching cutter mesh, not xfem volume mesh
  capabilities = 'unique_id'
  detail = ' properly moving crack front nodes using SCC-driven non-uniform growth, or'
[]


[face_cut_corner_scc]
  type = Exodiff
  input = 'face_crack_3d_domain.i face_crack_3d_xfem_scc.i'
  cli_args = 'fname=hex_block offset=0.21'
  exodiff = 'face_crack_scc_off_0.21_spin_0_XFEMCutMeshOutput.e'
  map = true # only matching cutter mesh, not xfem volume mesh
  capabilities = 'unique_id'
  detail = ' properly moving crack front nodes for a corner crack using SCC-driven non-uniform growth, or'
[]


[inactive_refine]
  type = Exodiff
  input = 'face_crack_3d_domain.i face_crack_3d_xfem_scc.i'
  cli_args = 'fname=hex_block spin=25 Executioner/end_time=2'
  exodiff = 'face_crack_scc_off_0_spin_25_XFEMCutMeshOutput.e'
  map = true # only matching cutter mesh, not xfem volume mesh
  capabilities = 'unique_id'
  detail = ' properly refining surface cutting crack front if crack front refinement occurs inside volume, or'
[]


[inactive_no_refine]
  type = Exodiff
  input = 'face_crack_3d_domain.i face_crack_3d_xfem_scc.i'
  cli_args = 'fname=hex_block spin=15 Executioner/end_time=2'
  exodiff = 'face_crack_scc_off_0_spin_15_XFEMCutMeshOutput.e'
  map = true # only matching cutter mesh, not xfem volume mesh
  capabilities = 'unique_id'
  detail = ' not refining surface cutting crack front if crack front refinement would occur outside volume, or'
[]


[face_cut_mid_function]
  type = Exodiff
  input = 'face_crack_3d_domain.i face_crack_3d_xfem_function.i'
  cli_args = 'fname=hex_block'
  exodiff = 'face_crack_function_off_0_spin_0_XFEMCutMeshOutput.e'
  map = true # only matching cutter mesh, not xfem volume mesh
  capabilities = 'unique_id'
  detail = ' without producing degenerate crack face elements with a prescribed function growth direction, or'
[]


[double_cut_edge]
  type = Exodiff
  input = 'face_crack_3d_domain.i face_crack_3d_xfem_radialFunc.i'
  cli_args = 'fname=hex_block spin=4'
  exodiff = 'hex_block_offset_0_spin_4_XFEMCutMeshOutput.e'
  map = true # only matching cutter mesh, not xfem volume mesh
  capabilities = 'unique_id'
  detail = ' growing the crack front and double cutting a volume element edge, or'
[]


[tet_hit_corner]
  type = Exodiff
  input = 'face_crack_3d_domain.i face_crack_3d_xfem_radialFunc.i'
  cli_args = 'fname=tet_corner offset=-0.05'
  exodiff = 'tet_corner_offset_-0.05_spin_0_XFEMCutMeshOutput.e'
  map = true # only matching cutter mesh, not xfem volume mesh
  # tet meshes are slightly over 1500MB valgrind memory limits
  capabilities = 'unique_id & method=opt'
  detail = ' keeping the crack front on the free surface when the crack front grows into a corner on the volume, or'
[]


[tet_concave_up]
  type = Exodiff
  input = 'face_crack_3d_domain.i face_crack_3d_xfem_radialFunc.i'
  cli_args = 'fname=tet_concave_up spin=10'
  exodiff = 'tet_concave_up_offset_0_spin_10_XFEMCutMeshOutput.e'
  map = true # only matching cutter mesh, not xfem volume mesh
  # tet meshes are slightly over 1500MB valgrind memory limits
  capabilities = 'unique_id & method=opt'
  detail = ' keeping the crack front on a concave-up curved volume surface, or'
[]


[tet_concave_down]
  type = Exodiff
  input = 'face_crack_3d_domain.i face_crack_3d_xfem_radialFunc.i'
  cli_args = 'fname=tet_concave_down spin=5'
  exodiff = 'tet_concave_down_offset_0_spin_5_XFEMCutMeshOutput.e'
  map = true # only matching cutter mesh, not xfem volume mesh
  # tet meshes are slightly over 1500MB valgrind memory limits
  capabilities = 'unique_id & method=opt'
  detail = ' keeping the crack front on a concave-down curved volume surface, or'
[]


[tet_concave_up_hoopStress]
  type = Exodiff
  input = 'face_crack_3d_domain.i face_crack_3d_xfem_hoopStress.i'
  cli_args = 'fname=tet_concave_up spin=12'
  exodiff = 'face_crack_hoopStress_off_0_spin_12_XFEMCutMeshOutput.e'
  map = true # only matching cutter mesh, not xfem volume mesh
  # tet meshes are slightly over 1500MB valgrind memory limits
  capabilities = 'unique_id & method=opt'
  detail = ' keeping the crack front consistent on a concave-up curved volume surface under the maximum hoop stress growth direction, or'
[]


[tet_block_tilt_14]
  type = Exodiff
  input = 'face_crack_3d_domain.i face_crack_3d_xfem_radialFunc.i'
  cli_args = 'fname=tet_block tilt=14 Outputs/file_base=tet_block_tilt_14'
  exodiff = 'tet_block_tilt_14_XFEMCutMeshOutput.e'
  map = true # only matching cutter mesh, not xfem volume mesh
  # tet meshes are slightly over 1500MB valgrind memory limits
  capabilities = 'unique_id & method=opt'
  detail = ' growing a tilted crack through a tetrahedral volume when two geometric cut surfaces place their intersections on the same fragment face in a single growth step.'
[]

Introduction
Dependencies
Failure Analysis Requirements