Data Structure: Util_set_boundary_data |
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Settings for generation of boundary data for restoration to forward analysis model creation. |
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Util_set_boundary_data NUM=ival where ival is the data structure number |
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Overview Util_set_boundary_data structure may be used to specify the settings for generation of boundary data for restoration to forward analysis model creation. The data settings comprise: •Definition of the type of side boundaries •Definition of the type of basal boundary conditions •Top surface load
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![]() | Side_boundary_flag Type of side boundary condition |
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Flag to indicate the type of side boundary. Valid types of side boundary are: • 1 - Vertical side boundaries defined by the motion of the basal boundary surface (Default) • 3 - Non vertical side boundaries fully defined by the restored geometry
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![]() | Basal_boundary_flag Type of basal boundary condition |
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Flag to define the type of basal boundary condition. The basal boundary is defined by part geometry which is updated over the step to represent the prescribed movement of the basal surface. The boundary condition is applied to the basal horizon (which is represented by geometry and is therefore meshed) by either a prescribed boundary condition ( Prescribed_boundary) or via contact (2-D only). The advantage of the contact method is that different friction coefficients can be assigned to the segments of the basal horizon representing the sediment horizon and the fault surfaces. The valid types of basal boundary are: • 1 - Prescribed boundary (Default in 3D) • 2 - Contact boundary condition (Default in 2D) • 3 - Prescribed boundary for basal horizon and Contact boundary condition for faults • 4 - Prescribed boundary for basal boundary with contact at faults and Basal_displacement (2D only)
Notes •If fault offset inversion occurs, or the fault offset becomes zero, boundary type 3 is only suitable for the case where faults intersecting the basal surface are discretised with discrete contact. If a continuum representation were to be used for the faults, then the prescribed boundary displacement would try to enforce a zero volume element when zero offset is achieved
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![]() | Side_lagrangian_algorithm Type of Lagrangian boundary surface for side boundaries |
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Allows to define the type of lagrangian algorithm that will be used in the forward simulation for the prescribed side boundaries. Generally side boundaries would use the "Normal" algorithm to allow compaction to occur freely (displacement tangential to the boundary is unconstrained). The available options are: • "Prescribed" - All the displacement components in side boundaries are prescribed according to restoration displacements • "Normal" - Only displacement normal to the side boundaries will be constrained from restoration displacements (Default)
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![]() | Basal_lagrangian_algorithm Type of Lagrangian boundary surface for basal boundaries |
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Allows to define the type of lagrangian algorithm that will be used in the forward simulation for the prescribed basal boundary. The available options are: • "Prescribed" - All the displacement components in the basal boundary are prescribed according to restoration displacements (Default) • "Normal" - Only displacement normal to the basal boundary will be constrained from restoration displacements
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![]() | Side_boundary_geometry_sets List of geometry sets defining side boundaries |
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Specifies the list of geometry sets defining side boundaries (maximum 32 characters each).
Notes •If a list of boundary geometry sets is not defined all sets with 'Edge' will be assumed to be side boundaries
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![]() | Basal_boundary_geometry_sets List of geometry sets associated with the prescribed basal boundary |
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List of geometry sets associated with basal prescribed boundary
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![]() | Basal_edge_fixity_flags Basal edge_fixity flags (1-Prescribed, 0-Free) |
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Optional keyword to write Edge_element_fixity_flags keyword data to the\k Prescribed_boundary_data structures in the forward analysis data file. Note that this data is only applicable to geometry sets defining the basal boundary and when the\k Prescribed_boundary_data is used in conjuction with\k Basal_displacement data structure.
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![]() | Applied_stress Mechanical surface pressure |
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Defines the value of the mechanical surface pressure. This may be defined either as an instantaneous load or with a load curve assigned using a time curve via Time_curve_stress
Notes •In most of the problems a prescribed small surface stress is recommended in order to prevent near surface material flow problems (e.g. when the stresses become positive). The stress is usually set to be equivalent to the load that exerts the top 50 m - 100 m of sediment.
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![]() | Side_boundary_extension Vertical side boundary extension distance |
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The vertical side boundary extension distance increases the height of the side boundary to prevent loss of contact due to under-considation i.e. increased elevation of the sediment in the forward model relative to the restoration. Side_boundary_extension is specified as an absolute value with the default being 0.5 * side boundary height
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![]() | Side_boundary_name_flag Flag indicating the naming convention for side boundaries |
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Flag indicating the name convention for side boundaries in 2D problems. Valid values are: • 1 - "East", "West" • 2 - "lhs_boundary", "rhs_boundary"
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![]() | Spatial_groups List of groups to be used for spatial boundary constraints |
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List of groups to be used for spatial boundary constraints (maximum 32 characters each).
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![]() | Spatial_entity_type Entity type to be used for spatial boundary conditions ("Line" or "Surface") |
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Entity type to be used for spatial boundary conditions in the forward model. Valid values are: • "Line" - Spatial boundaries will be defined by lines • "Surface" - Spatial boundaries will be defined by surfaces (Default in 2-D)
Notes •If type "Line" is specified without a list of Spatial_lines then all external lines corresponding to the surfaces used in the group list will be prescribed. •If type "Surface" is specified then all external surfaces used in the group list will be prescribed.
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![]() | Spatial_lines List of lines with spatial boundary conditions |
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List of lines with spatial boundary conditions
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![]() | Side_boundary_reorder_flag Flag indicating the order of the lines defining side boundaries should be ordered automatically |
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Flag indicating the order of the lines defining side boundaries should be ordered automatically. Valid values are: • 0 - No reordering of side boundary lines • 1 - Reorder side boundary lines if required
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![]() | Time_curve_side_bound Time curve for side boundary constraints |
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Time curve number for side boundary constraints |
![]() | Time_curve_basal_bound Time curve for basal boundary constraints |
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Time curve number for basal boundary constraints |