ProjectParameter.json file description

Note: The user is responsible for giving all material parameters a consistent set of parameters.

Process description template

{
  "python_module": "Python_module_name",
  "kratos_module": "Kratos_module_name",
  "process_name": "C++_process_name",
  "Parameters": {
    "List_of_all_process_parameters": "..."
  }
}

Main ProjectParameters structure

Parameters	Description
`"problem_data": {`	Problem data
`"problem_name": "DSettlement_stage0"`	Name of this problem case
`"start_time": -1E-06`	Start time of this stage in seconds
`"end_time": 0.0`	End time of this stage in seconds
`"echo_level": 1`	Level of logging
`"parallel_type": "OpenMP"`	Method of parallel computation
`"number_of_threads": 1`	Number of threads for parallel computation
`"solver_settings": {`	Steering parameters of the analysis
`"solver_type": "U_Pw"`	Analysis type (OpenMP: u_pw/geomechanics_u_pw_solver/twophase/pw/geomechanics_pw_solver/dynamic/scipy, MPI: dynamic)
`"model_part_name": "PorousDomain"`	Selection of model parts to use for computation
`"domain_size": 2`	Working space dimension
`"model_import_settings": { "input_type": "mdpa", "input_filename": "mesh_stage0" }`	Model input format and file
`"material_import_settings": { "materials_filename": "MaterialParameters.json" }`	Material parameter file
`"time_stepping": { ... }`	Time-stepping information
`"time_step"`	Initial time step size
`"max_delta_time_factor"`	Maximum scaling factor for next time step
`"minimum_allowable_value"`	Tolerance to avoid very small final time steps
`"buffer_size": 2`	Number of solution vectors to keep
`"clear_storage": false`	Solver storage behavior
`"compute_reactions": false`	Compute stress/internal/reaction forces
`"move_mesh_flag": false`	Update nodal positions with displacement
`"reform_dofs_at_each_step": false`	Rebuild system at each step
`"block_builder": true`	Builder and solver block mode
`"solution_type": "K0-Procedure"`	Calculation type: quasi_static, dynamic, k0_procedure, transient_groundwater_flow, steady_state_groundwater_flow
`"scheme_type": "Newmark"`	Time integration scheme: newmark, backward_euler
`"reset_displacements": true`	Reset total displacements/rotations at stage start
`"strategy_type": "line_search"`	Iterative strategy: newton_raphson, newton_raphson_with_piping, line_search, arc_length
`"convergence_criterion": "displacement_criterion"`	Convergence criterion type
`"water_pressure_relative_tolerance"`	Relative tolerance
`"water_pressure_absolute_tolerance"`	Absolute tolerance
`"displacement_relative_tolerance"`	Relative tolerance
`"displacement_absolute_tolerance"`	Absolute tolerance
`"residual_relative_tolerance"`	Relative tolerance
`"residual_absolute_tolerance"`	Absolute tolerance
`"min_iterations": 6`	Increase next step if converged below this iteration count
`"max_iterations": 15`	Maximum number of iterations
`"number_cycles": 100`	Maximum number of scaled-down retry cycles
`"reduction_factor": 0.5`	Time-step reduction factor
`"increase_factor": 2.0`	Time-step increase factor
`"desired_iterations": 4`	Arc-length parameter
`"max_radius_factor": 10.0`	Arc-length parameter
`"min_radius_factor": 0.1`	Arc-length parameter
`"calculate_reactions": true`	Reaction calculation toggle
`"max_line_search_iterations": 5`	Line-search parameter
`"first_alpha_value": 0.5`	Line-search parameter
`"second_alpha_value": 1.0`	Line-search parameter
`"min_alpha": 0.1`	Line-search parameter
`"max_alpha": 2.0`	Line-search parameter
`"line_search_tolerance": 0.5`	Line-search parameter
`"rotation_dofs": true`	Include rotational degrees of freedom
`"linear_solver_settings": { ... }`	Linear equation solver settings
`"linear_solver_settings.solver_type": "LinearSolversApplication.sparse_lu"`	Supported options include amgcl, bicgstab, cg, sparse_lu, sparse_qr, tfqmr and others
`"linear_solver_settings.scaling": true`	Solver scaling setting
`"problem_domain_sub_model_part_list"`	List of elements (soil, beams, anchors, interfaces)
`"processes_sub_model_part_list"`	List of conditions (BCs, loads, water conditions, etc.)
`"body_domain_sub_model_part_list"`	List of body elements
`"newmark_beta": 0.25`	Newmark parameter
`"newmark_gamma": 0.5`	Newmark parameter
`"newmark_theta": 0.5`	Time integration parameter for water pressure DOF
`"rayleigh_m": 0.0`	Mass contribution to damping
`"rayleigh_k": 0.0`	Stiffness contribution to damping
`"output_processes": {`	Post-process settings
`"gid_output": [...]`	Write output files for GiD postprocessor
`"GiDPostMode": "GiD_PostAscii"`	Write results in GiD binary or ASCII
`"nodal_results": [...]`	Nodal output results
`"gauss_point_results": [...]`	Gauss-point output results
`"processes": {`	Begin process lists
`"constraints_process_list": [...]`	Constraint process list
`"loads_process_list": [...]`	Load process list
`"auxiliar_process_list": [...]`	Auxiliary process list

Displacement boundary conditions process

Placed in constraints_process_list.

Used for displacement boundary conditions such as fixities, sliders, rollers, and hinges.

{
  "python_module": "apply_vector_constraint_table_process",
  "kratos_module": "KratosMultiphysics.GeoMechanicsApplication",
  "process_name": "ApplyVectorConstraintTableProcess",
  "Parameters": {
    "model_part_name": "PorousDomain.xxx",
    "variable_name": "DISPLACEMENT",
    "active": [true, true, true],
    "is_fixed": [true, true, true],
    "value": [0.0, 0.0, 0.0],
    "table": [0, 0, 0]
  }
}

Parameter	Description
`model_part_name`	Body part to apply the process to. `PorousDomain.` is required
`variable_name`	Kratos vector variable
`active`	Activation per vector component (X, Y, Z)
`is_fixed`	Fix/free per vector component (X, Y, Z)
`value`	Prescribed value per component
`table`	Time-table reference per component

Hydrostatic water pressure boundary conditions process

Placed in constraints_process_list.

Used for pore water pressure boundary conditions with hydrostatic increase in depth direction.

{
  "python_module": "apply_scalar_constraint_table_process",
  "kratos_module": "KratosMultiphysics.GeoMechanicsApplication",
  "process_name": "ApplyScalarConstraintTableProcess",
  "Parameters": {
    "model_part_name": "PorousDomain.xxx",
    "variable_name": "WATER_PRESSURE",
    "is_fixed": true,
    "fluid_pressure_type": "Hydrostatic",
    "gravity_direction": 1,
    "reference_coordinate": -25.0,
    "table": 0,
    "pressure_tension_cut_off": 0.0,
    "specific_weight": 9810.0
  }
}

Parameter	Description
`model_part_name`	Body part to apply the process to. `PorousDomain.` is required
`variable_name`	Kratos scalar variable
`is_fixed`	Dirichlet (`true`) or initial value (`false`)
`fluid_pressure_type`	`Hydrostatic`, `Uniform`, etc.
`gravity_direction`	0, 1, 2 for X, Y, Z
`reference_coordinate`	Phreatic surface coordinate in gravity direction
`table`	Time-table reference
`pressure_tension_cut_off`	Threshold value to eliminate suction
`specific_weight`	Density of water times gravity

Gravity load process

Placed in loads_process_list.

Used for gravity/self-weight/body-acceleration loads.

{
  "python_module": "apply_vector_constraint_table_process",
  "kratos_module": "KratosMultiphysics.GeoMechanicsApplication",
  "process_name": "ApplyVectorConstraintTableProcess",
  "Parameters": {
    "model_part_name": "PorousDomain.xxx",
    "variable_name": "VOLUME_ACCELERATION",
    "active": [false, true, false],
    "value": [0.0, -9.81, 0.0],
    "table": [0, 0, 0]
  }
}

Parameter	Description
`model_part_name`	Body part to apply load conditions to
`variable_name`	Kratos vector variable
`active`	Activation per component (X, Y, Z)
`value`	Prescribed value per component
`table`	Time-table reference per component

K0 procedure process

Placed in auxiliar_process_list.

Used for K0 procedure after stress initialization.

{
  "python_module": "apply_k0_procedure_process",
  "kratos_module": "KratosMultiphysics.GeoMechanicsApplication",
  "process_name": "ApplyK0ProcedureProcess",
  "Parameters": {
    "model_part_name": "PorousDomain.xxx",
    "variable_name": "CAUCHY_STRESS_TENSOR"
  }
}

Parameter	Description
`model_part_name`	Body part to apply the K0 procedure to
`variable_name`	Kratos tensor variable for K0, usually `CAUCHY_STRESS_TENSOR`

References

More general information can be found on the Kratos website:

https://github.com/KratosMultiphysics/Kratos/wiki/Kratos-input-files-and-IO#3-the-project-parameters-file