7 heat_transfer_definitions#(struct:traverse-element #<procedure:...lib/render-cond.rkt:38:12>)

7 heat_transfer_definitions (alpha)

Contains all the definitions specific to a heat transfer procedure.

Name	Type	Description	Default
boundary_conditions (alpha) [optional]	LIST	A boundary condition object defines a static or kinematic boundary condition. Boundary conditions can be applied to sets representing both boundaries and bodies.
load_conditions (alpha) [optional]	LIST	The load_conditions object defines applied loads. Loads can be applied to sets representing boundaries and bodies.
outputs (alpha) [optional]	LIST	The outputs object holds all output objects, identified by user defined identifiers. An output object defines an output for this procedure. Remark: If a chosen set was specified as an immersed set during geometry creation, that set must the only item in the sets list. If an immersed set is selected the output command will produce two separate files. The main file will include a tessellated surface representation of the boundary. The second file (with suffix envelope), will include a smooth volumetric output of the U-spline envelope domain for the immersed set. When viewing results on the envelope domain take care that only values on the interior of the model of interest are considered as values at the extremities of this representation may not exhibit physically relevant behavior. Not all elements from the original mesh used may be shown, in general only those that intersect the model of interest will be included.
probes (alpha) [optional]	LIST	The probes object holds all user defined probe_variables. Probe variables are used to track quantities of interest at specific locations in a model over time. For example, a user may want to track von Mises stress at a specific location in a model over time.
interactions (alpha) [optional]	LIST	Each object in the interaction definitions array defines an interaction for the procedure. Currently the supported interaction is tied_constraint.
interaction_search_parameters (beta) [optional]	LIST	Each object in the interaction search definitions array defines search parameters to be used in an interaction. Currently the supported search definitions is a sensor-based layout.
interaction_properties (beta) [optional]	LIST	The interaction property definition allows the user to define the type of friction and movement that occurs once contact is initiated.

7.1 boundary_conditions (alpha)

A boundary condition object defines a static or kinematic boundary condition. Boundary conditions can be applied to sets representing both boundaries and bodies.

Name	Type	Description	Default
label (alpha)	STRING	A user defined identifier for this boundary condition.
temperature (alpha)	SUB OBJECT	Defines the type of temperature boundary condition
part \| set	STRING \| STRING	Defines the set or part to be operated on
penalty [optional] (alpha)	DOUBLE	Penalty factor for weak enforcement of the boundary condition. Boundary conditions in Coreform IGA are weakly enforced. This parameter assigns a penalty that essentially dictates how "close" the computed solution should respect the desired boundary condition. This parameter is selected from the range [0, infinity] where when = infinity the enforcement is equivalent to a strongly-enforced boundary condition. In practice as the value increases, the conditioning of the resulting linear systems increases, which can result in a linear system that is more difficult to solve with iterative methods and lowers the precision of the computed solution. Thus a general rule of thumb is that a boundary condition should be chosen to be only ~100x-1000x larger than $\kappa h^{1-d}$ , where $\kappa$ is the thermal conductivity of the material involved in the boundary condition, $h$ is the length scale of the mesh resolution, and $d$ is the dimension of the constrained set (e.g., $d=2$ for a constrained surface, $d=3$ for a constrained volume, etc.).
quadrature_options (beta) [optional]	SUB OBJECT	See linked documentation

7.1.1 temperature (alpha)

Describes a fixed temperature boundary condition

Name	Type	Description	Default
scale_factor [optional] (alpha)	DOUBLE	A scalar value which scales the function.	1.0
function (alpha)	STRING	The user defined identifier of the temporal function.

7.1.2 part | set

Defines the set or part to be operated on

Name	Type	Description	Default
part	STRING	The user defined label of the part that defines the set.
set	STRING	The user defined identifier of the geometric set.

7.1.3 quadrature_options (beta)

Name	Type	Description	Default
quadrature [optional] (beta)	“QP1” \| “QP0” \| “Q1” \| “Q2” \| “Q3” \| “Q4” \| “Q5” \| “Q6” \| “Q7” \| “Q8” \| “Q9” \| “Q10”	Quadrature type enumeration. The quadrature type determines the point layout over a patch or patch element. The schemes following the pattern “Q#” specify that a Gauss quadrature scheme with #-points will be used. The schemes following the pattern “QP#” specify that a Gauss quadrature scheme with $(P+\#)$ -points will be used, where $P$ is the degree of the patch's or patch element's basis.	QP1
optimized_cut_quadrature_strategy [optional] (beta)	“match_uncut” \| “reduce_from_uncut” \| “match_basis”	Strategy to choose the degree of accuracy for quadrature on cut cells. The default strategy of chooses quadrature rules with similar numbers of points as those used on uncut cells, as specified by ; it has lower formal accuracy (integrating tensor products of monomials up to degree $N-1$ for uncut quadrature $N$ ), but is a good default choice for practical calculations. The strategy match_uncut matches the formal accuracy of the quadrature on uncut cells, but is significantly more costly. The strategy match_basis chooses a rule that exactly integrates the basis functions; this is equivalent to reduce_from_uncut if the uncut cells use the default quadrature of QP1, but may differ for other choices of uncut quadrature.	reduce_from_uncut
optimized_cut_quadrature_degree [optional] (beta)	NONNEGATIVE INTEGER	If provided, this value overrides optimized_cut_quadrature_strategy by specifying an explicit polynomial degree of accuracy for optimized quadrature rules on cut cells.
optimization_method [optional] (beta)	“tet_pruning” \| “grid_doubling” \| “linear_programming”	Specifies the preferred method of quadrature generation for cut cells. If the preferred method fails on a particular cell, the other methods will be used in an attempt to recover.	tet_pruning
optimization_residual_tolerance [optional] (beta)	DOUBLE	The absolute residual tolerance used in quadrature optimization on cut cells. A smaller value will result in a more accurate quadrature rule, but may increase the time to compute quadrature rules for cut cells.	1e-12
optimization_lawson_hanson_solve_completion [optional]	true\|false	An experimental option that controls the convergence behavior of quadrature optimization. For best results it is recommended to set this value to true. If set to true this causes each iteration of quadrature optimization to solve to the highest accuracy possible. The results at each iteration are then checked against the optimization_residual_tolerance to determine if a sufficient rule has been found. If this value is set to false then the optimization_residual_tolerance is passed to the solve at each iteration and can cause the solve step to terminate more quickly which can result in faster execution and a lower number of quadrature points. However the quality and accuracy of the resulting rule may be suspect.	true

7.2 load_conditions (alpha)

The load_conditions object defines applied loads. Loads can be applied to sets representing boundaries and bodies.

Name	Type	Description	Default
label (alpha)	STRING	User defined identifier for this load condition.
surface_heat_flux (alpha) \| line_heat_flux (alpha) \| point_heat_source (alpha) \| body_heat_source (alpha) \| ambient_radiation (alpha) \| convective_transfer (alpha)	SUB OBJECT \| SUB OBJECT \| SUB OBJECT \| SUB OBJECT \| SUB OBJECT \| SUB OBJECT	One of the given keywords must be defined to specify the class of heat transfer loading
part \| set	STRING \| STRING	Defines the set or part to be operated on
quadrature_options (beta) [optional]	SUB OBJECT	See linked documentation

7.2.1 surface_heat_flux (alpha)

Name	Type	Description	Default
scale_factor [optional] (alpha)	DOUBLE	A scalar value which scales the function.	1.0
function (alpha)	STRING	The user defined identifier of the temporal function.

7.2.2 line_heat_flux (alpha)

Name	Type	Description	Default
scale_factor [optional] (alpha)	DOUBLE	A scalar value which scales the function.	1.0
function (alpha)	STRING	The user defined identifier of the temporal function.

7.2.3 point_heat_source (alpha)

Name	Type	Description	Default
scale_factor [optional] (alpha)	DOUBLE	A scalar value which scales the function.	1.0
function (alpha)	STRING	The user defined identifier of the temporal function.

7.2.4 body_heat_source (alpha)

User must use the ’part’ option when defining sets for a body heat source

Name	Type	Description	Default
scale_factor [optional] (alpha)	DOUBLE	A scalar value which scales the function.	1.0
function (alpha)	STRING	The user defined identifier of the temporal function.

7.2.5 ambient_radiation (alpha)

Name	Type	Description	Default
scale_factor [optional] (alpha)	DOUBLE	A scalar value which scales the function.	1.0
function (alpha)	STRING	The user defined identifier of the temporal function.
emissivity (alpha)	DOUBLE	The emissivity of the boundary.

7.2.6 convective_transfer (alpha)

Name	Type	Description	Default
scale_factor [optional] (alpha)	DOUBLE	A scalar value which scales the function.	1.0
function (alpha)	STRING	The user defined identifier of the temporal function.
heat_transfer_coefficient (alpha)	DOUBLE	The heat transfer coefficient of the boundary.

7.2.7 part | set

Defines the set or part to be operated on

Name	Type	Description	Default
part	STRING	The user defined label of the part that defines the set.
set	STRING	The user defined identifier of the geometric set.

7.2.8 quadrature_options (beta)

Name	Type	Description	Default
quadrature [optional] (beta)	“QP1” \| “QP0” \| “Q1” \| “Q2” \| “Q3” \| “Q4” \| “Q5” \| “Q6” \| “Q7” \| “Q8” \| “Q9” \| “Q10”	Quadrature type enumeration. The quadrature type determines the point layout over a patch or patch element. The schemes following the pattern “Q#” specify that a Gauss quadrature scheme with #-points will be used. The schemes following the pattern “QP#” specify that a Gauss quadrature scheme with $(P+\#)$ -points will be used, where $P$ is the degree of the patch's or patch element's basis.	QP1
optimized_cut_quadrature_strategy [optional] (beta)	“match_uncut” \| “reduce_from_uncut” \| “match_basis”	Strategy to choose the degree of accuracy for quadrature on cut cells. The default strategy of chooses quadrature rules with similar numbers of points as those used on uncut cells, as specified by ; it has lower formal accuracy (integrating tensor products of monomials up to degree $N-1$ for uncut quadrature $N$ ), but is a good default choice for practical calculations. The strategy match_uncut matches the formal accuracy of the quadrature on uncut cells, but is significantly more costly. The strategy match_basis chooses a rule that exactly integrates the basis functions; this is equivalent to reduce_from_uncut if the uncut cells use the default quadrature of QP1, but may differ for other choices of uncut quadrature.	reduce_from_uncut
optimized_cut_quadrature_degree [optional] (beta)	NONNEGATIVE INTEGER	If provided, this value overrides optimized_cut_quadrature_strategy by specifying an explicit polynomial degree of accuracy for optimized quadrature rules on cut cells.
optimization_method [optional] (beta)	“tet_pruning” \| “grid_doubling” \| “linear_programming”	Specifies the preferred method of quadrature generation for cut cells. If the preferred method fails on a particular cell, the other methods will be used in an attempt to recover.	tet_pruning
optimization_residual_tolerance [optional] (beta)	DOUBLE	The absolute residual tolerance used in quadrature optimization on cut cells. A smaller value will result in a more accurate quadrature rule, but may increase the time to compute quadrature rules for cut cells.	1e-12
optimization_lawson_hanson_solve_completion [optional]	true\|false	An experimental option that controls the convergence behavior of quadrature optimization. For best results it is recommended to set this value to true. If set to true this causes each iteration of quadrature optimization to solve to the highest accuracy possible. The results at each iteration are then checked against the optimization_residual_tolerance to determine if a sufficient rule has been found. If this value is set to false then the optimization_residual_tolerance is passed to the solve at each iteration and can cause the solve step to terminate more quickly which can result in faster execution and a lower number of quadrature points. However the quality and accuracy of the resulting rule may be suspect.	true

7.3 outputs (alpha)

The outputs object holds all output objects, identified by user defined identifiers. An output object defines an output for this procedure. Remark: If a chosen set was specified as an immersed set during geometry creation, that set must the only item in the sets list. If an immersed set is selected the output command will produce two separate files. The main file will include a tessellated surface representation of the boundary. The second file (with suffix envelope), will include a smooth volumetric output of the U-spline envelope domain for the immersed set. When viewing results on the envelope domain take care that only values on the interior of the model of interest are considered as values at the extremities of this representation may not exhibit physically relevant behavior. Not all elements from the original mesh used may be shown, in general only those that intersect the model of interest will be included.

Name	Type	Description	Default
label (alpha)	STRING	The user defined identifier for this output definition.
tessellate [optional] (alpha)	true\|false	The output should be tessellated to hdf5 files for consumption by third party tools.
field (alpha) \| history (alpha)	SUB OBJECT \| SUB OBJECT	One of the given keywords must be defined to specify the class of output

Example Usage:
outputs: [ { label: "field_results", field: { database_name: "results", interval: "output_interval", part: "cframe", variables: { displacement: [ "x", "y", "z" ], stress: [ "all" ] }, element_variable_output_strategy: "interpolate", include_integration_point_output: false } }, { label: "probe_results", history: { interval: "output_interval", probe_variables: [ "stress_probe", "load_reaction_force" ] } } ]

7.3.1 field (alpha)

The field object is primarily useful for visualization and explorative analysis of the results. In addition to the result values, field output exports information needed to construct a visualization of the model.

Name	Type	Description	Default
database_name (alpha)	STRING	The file name prefix of the output file that will be written to disk. The field output is written out in the ParaView *.pvd format.
interval (alpha)	STRING	The user defined identifier of the interval to use for this output. This interval will specify when the output should be written, as determined by the time_increment or step_increment values within the interval. A time_increment of 0 acts the same as a step_increment of either 0 or 1, writing output after each intermediate solution step. A negative value for time_increment or step_increment will output only at the bounds of the interval.
part \| set	STRING \| STRING	Defines the set or part to be operated on. If nothing is specified, it is equivalent to including every part.
variables (alpha)	SUB OBJECT	See linked documentation
element_variable_output_strategy [optional] (alpha)	“max” \| “min” \| “average” \| “interpolate”	This specifies how values are calculated within each cell. min, max, and average take the minimum, maximum, or average component point values at the integration points and report them across the entire cell. interpolate interpolates the component values from the integration points.

7.3.1.1 part | set

Defines the set or part to be operated on. If nothing is specified, it is equivalent to including every part.

Name	Type	Description	Default
part	STRING	The user defined label of the part that defines the set.
set	STRING	The user defined identifier of the geometric set.

7.3.1.2 variables (alpha)

The variable to output.

Name		Type		Description		Default
temperature (alpha) \| heat_flux (alpha)		[ “value”, ... ] \| [ “all” \| “x” \| “y” \| “z” \| “magnitude”, ... ]		Any of the given options can be defined

7.3.1.3 temperature | heat_flux

Any of the given options can be defined

Name	Type	Description	Default
temperature (alpha)	[ “value”, ... ]
heat_flux (alpha)	[ “all” \| “x” \| “y” \| “z” \| “magnitude”, ... ]

7.3.2 history (alpha)

Define a history object to extract time-history data from specific regions of interest. The history object is primarily useful for analysis at known regions of interest (ROI), especially when a high-temporal resolution is required to gain useful information from the results. Field output on the entire domain of the model is often intractable in these situations as writing the entire field at a high sample rate can negatively impact performance, especially when using explicit time-integration, and can quickly generate enormous files that are cumbersome to process. History output writes a minimal set of information at user define probe_variable locations to an HDF5 file format that is easy to process in any number of downstream tools such as Excel, Matlab, or Python.

Name	Type	Description	Default
interval (alpha)	STRING	The user defined identifier of the interval to use for this output.
probe_variables (alpha)	[ STRING, ... ]	The user-defined probe_variables that should be included in the output file.

7.4 probes (alpha)

The probes object holds all user defined probe_variables. Probe variables are used to track quantities of interest at specific locations in a model over time. For example, a user may want to track von Mises stress at a specific location in a model over time.

Name	Type	Description	Default
label (alpha)	STRING	The user defined identifier for this probe definition.
field (alpha) \| integrated_surface_quantity (alpha) \| l2_error_norm (alpha)	SUB OBJECT \| SUB OBJECT \| SUB OBJECT	One of the given keywords must be defined to specify the class of probe

Example Usage:
probes: [ { label: "stress_probe", field: { single_point: { location: [ 0, -1.5, -4.25 ] }, location_configuration: "reference", field_variable_configuration: "reference", variables: { stress: [ "max_principal" ] } } }, { label: "load_reaction_force", integrated_surface_quantity: { variables: { reaction_force: [ "x", "y", "z" ] }, part: "cframe", use_set_from_load_condition: "push_top" } } ]

7.4.1 field (alpha)

Defines a probe that extracts field variable data.

Name	Type	Description	Default
set (alpha) \| single_point (alpha) \| along_line (alpha) \| along_curve (alpha) \| extremum (alpha)	STRING \| SUB OBJECT \| SUB OBJECT \| SUB OBJECT \| SUB OBJECT	One of the given keywords must be defined to specify the class of field probe
location_configuration (alpha)	“reference”	Defines the configuration of the probe location. The reference configuration will track the same material point through time. The current configuration will track the field_variable at a specific spatial location. If no part of the model covers the location when tracking the current configuration then zero values will be returned. Currently, only reference is supported.
field_variable_configuration (alpha)	“reference”	The configuration of the output coordinate system. Currently, only reference is supported.
variables (alpha)	SUB OBJECT	See linked documentation

7.4.1.1 set | single_point | along_line | along_curve | extremum

One of the given keywords must be defined to specify the class of field probe

Name	Type	Description	Default
set (alpha)	STRING	Specifies the user defined identifier of the set in the Flex model.
single_point (alpha)	SUB OBJECT	See linked documentation
along_line (alpha)	SUB OBJECT	See linked documentation
along_curve (alpha)	SUB OBJECT	See linked documentation
extremum (alpha)	SUB OBJECT	See linked documentation

7.4.1.2 single_point (alpha)

Name		Type		Description		Default
location (alpha)		[ DOUBLE, DOUBLE, DOUBLE ]		The coordinate location of the probe.

7.4.1.3 along_line (alpha)

Name	Type	Description	Default
start_location (alpha)	[ DOUBLE, DOUBLE, DOUBLE ]	The coordinate location of the first probe.
stop_location (alpha)	[ DOUBLE, DOUBLE, DOUBLE ]	The coordinate location of the last probe.
num_points (alpha)	NONNEGATIVE INTEGER	The number of probes between the first and last probe location (minimum 2).

7.4.1.4 along_curve (alpha)

Name		Type		Description		Default
locations (alpha)		[ [ DOUBLE, ... ], ... ]		The evaluated coordinate locations of all probes along the curve

7.4.1.5 extremum (alpha)

Name	Type	Description	Default
set [optional] (alpha)	STRING	Specifies the user defined identifier of the set in the Flex model in which the extremum value is to be found. If not defined then the entire model will be used.
minimum (alpha) \| maximum (alpha)	SUB OBJECT \| SUB OBJECT	One of the given keywords must be defined to specify the type of extremum probe

7.4.1.6 minimum (alpha)

The variable to track for the extremum.

Name		Type		Description		Default
temperature (alpha) \| heat_flux (alpha)		“value” \| “x” \| “y” \| “z” \| “magnitude”		One of the given keywords must be defined to specify the type of variable to output.

7.4.1.7 temperature | heat_flux

One of the given keywords must be defined to specify the type of variable to output.

Name	Type	Description	Default
temperature (alpha)	“value”
heat_flux (alpha)	“x” \| “y” \| “z” \| “magnitude”

7.4.1.8 maximum (alpha)

The variable to track for the extremum.

Name		Type		Description		Default
temperature (alpha) \| heat_flux (alpha)		“value” \| “x” \| “y” \| “z” \| “magnitude”		One of the given keywords must be defined to specify the type of variable to output.

7.4.1.9 temperature | heat_flux

One of the given keywords must be defined to specify the type of variable to output.

Name	Type	Description	Default
temperature (alpha)	“value”
heat_flux (alpha)	“x” \| “y” \| “z” \| “magnitude”

7.4.1.10 variables (alpha)

The variable to output.

Name		Type		Description		Default
temperature (alpha) \| heat_flux (alpha)		[ “value”, ... ] \| [ “all” \| “x” \| “y” \| “z” \| “magnitude”, ... ]		Any of the given options can be defined

7.4.1.11 temperature | heat_flux

Any of the given options can be defined

Name	Type	Description	Default
temperature (alpha)	[ “value”, ... ]
heat_flux (alpha)	[ “all” \| “x” \| “y” \| “z” \| “magnitude”, ... ]

7.4.2 integrated_surface_quantity (alpha)

Sum a variable on a specified surface.

Name	Type	Description	Default
variables (alpha)	SUB OBJECT	See linked documentation
part [optional] (alpha)	STRING	Specifies the user-defined label of the part in the FRM model in which the surface for integrating is on.
use_set_from_boundary_condition (alpha) \| use_set_from_load_condition (alpha) \| use_set_from_interaction (alpha)	STRING \| STRING \| STRING	The set for this probe must come from a user defined boundary condition, load condition or interaction.

Example Usage:
integrated_surface_quantity: { variables: { reaction_force: [ "x", "y", "z" ] }, part: "cframe", use_set_from_load_condition: "push_top" }

7.4.2.1 variables (alpha)

The variables to integrate.

Name		Type		Description		Default
reaction_flux (alpha)		[ “value”, ... ]		Definitions of the type of variables to integrate.

Example Usage:
variables: { reaction_force: [ "x", "y", "z" ] }

7.4.2.2 reaction_flux

Definitions of the type of variables to integrate.

Name		Type		Description		Default
reaction_flux (alpha)		[ “value”, ... ]

7.4.2.3 use_set_from_boundary_condition | use_set_from_load_condition | use_set_from_interaction

The set for this probe must come from a user defined boundary condition, load condition or interaction.

Name	Type	Description	Default
use_set_from_boundary_condition (alpha)	STRING	Specifies the set used in the boundary condition with this user-defined label. Used to get reaction forces associated with boundary conditions.
use_set_from_load_condition (alpha)	STRING	Specifies the set used in the load condition with this user-defined label. Used to get net forces from load conditions.
use_set_from_interaction (alpha)	STRING	Specifies the set used in the interaction with this user-defined label. Used to get contact reaction forces.

7.4.3 l2_error_norm (alpha)

Calculate an L2 error norm, over a given set, between the computed solution and a user-provided solution. The error is calculated from the difference between a given user function and the computed values for stress or displacement components. The error is defined as the square root of the sum of the squares of the given components

Name	Type	Description	Default
part \| set	STRING \| STRING	Defines the set or part to be operated on. If nothing is specified, it is equivalent to including every part.
function (alpha)	STRING	The user defined identifier of the function to use for this error calculation. The function should return the reference values that the solution will be compared with in an array ordered to match the provided components of displacement or stress.
variable (alpha)	SUB OBJECT	See linked documentation

7.4.3.1 part | set

Defines the set or part to be operated on. If nothing is specified, it is equivalent to including every part.

Name	Type	Description	Default
part	STRING	The user defined label of the part that defines the set.
set	STRING	The user defined identifier of the geometric set.

7.4.3.2 variable (alpha)

The variable to output.

Name		Type		Description		Default
temperature (alpha) \| heat_flux (alpha)		[ “value”, ... ] \| [ “all” \| “x” \| “y” \| “z” \| “magnitude”, ... ]		One of the given keywords must be defined to specify the type of variable to output.

7.4.3.3 temperature | heat_flux

One of the given keywords must be defined to specify the type of variable to output.

Name	Type	Description	Default
temperature (alpha)	[ “value”, ... ]
heat_flux (alpha)	[ “all” \| “x” \| “y” \| “z” \| “magnitude”, ... ]

7.5 interactions (alpha)

Each object in the interaction definitions array defines an interaction for the procedure. Currently the supported interaction is tied_constraint.

Name	Type	Description	Default
label (alpha)	STRING	User defined identifier for this interaction definition.
quadrature_options (beta) [optional]	SUB OBJECT	See linked documentation
tied_constraint (alpha) \| material_interface (alpha)	SUB OBJECT \| SUB OBJECT	One of the given keywords must be defined to specify the type of interaction

7.5.1 quadrature_options (beta)

Name	Type	Description	Default
quadrature [optional] (beta)	“QP1” \| “QP0” \| “Q1” \| “Q2” \| “Q3” \| “Q4” \| “Q5” \| “Q6” \| “Q7” \| “Q8” \| “Q9” \| “Q10”	Quadrature type enumeration. The quadrature type determines the point layout over a patch or patch element. The schemes following the pattern “Q#” specify that a Gauss quadrature scheme with #-points will be used. The schemes following the pattern “QP#” specify that a Gauss quadrature scheme with $(P+\#)$ -points will be used, where $P$ is the degree of the patch's or patch element's basis.	QP1
optimized_cut_quadrature_strategy [optional] (beta)	“match_uncut” \| “reduce_from_uncut” \| “match_basis”	Strategy to choose the degree of accuracy for quadrature on cut cells. The default strategy of chooses quadrature rules with similar numbers of points as those used on uncut cells, as specified by ; it has lower formal accuracy (integrating tensor products of monomials up to degree $N-1$ for uncut quadrature $N$ ), but is a good default choice for practical calculations. The strategy match_uncut matches the formal accuracy of the quadrature on uncut cells, but is significantly more costly. The strategy match_basis chooses a rule that exactly integrates the basis functions; this is equivalent to reduce_from_uncut if the uncut cells use the default quadrature of QP1, but may differ for other choices of uncut quadrature.	reduce_from_uncut
optimized_cut_quadrature_degree [optional] (beta)	NONNEGATIVE INTEGER	If provided, this value overrides optimized_cut_quadrature_strategy by specifying an explicit polynomial degree of accuracy for optimized quadrature rules on cut cells.
optimization_method [optional] (beta)	“tet_pruning” \| “grid_doubling” \| “linear_programming”	Specifies the preferred method of quadrature generation for cut cells. If the preferred method fails on a particular cell, the other methods will be used in an attempt to recover.	tet_pruning
optimization_residual_tolerance [optional] (beta)	DOUBLE	The absolute residual tolerance used in quadrature optimization on cut cells. A smaller value will result in a more accurate quadrature rule, but may increase the time to compute quadrature rules for cut cells.	1e-12
optimization_lawson_hanson_solve_completion [optional]	true\|false	An experimental option that controls the convergence behavior of quadrature optimization. For best results it is recommended to set this value to true. If set to true this causes each iteration of quadrature optimization to solve to the highest accuracy possible. The results at each iteration are then checked against the optimization_residual_tolerance to determine if a sufficient rule has been found. If this value is set to false then the optimization_residual_tolerance is passed to the solve at each iteration and can cause the solve step to terminate more quickly which can result in faster execution and a lower number of quadrature points. However the quality and accuracy of the resulting rule may be suspect.	true

7.5.2 tied_constraint (alpha)

Defines interaction properties for a surface to surface tied constraint.

Name	Type	Description	Default
target_set (alpha)	STRING	Specifies the target interaction surface.
source_set (alpha)	STRING	Specifies the source interaction surface.
region_search_method (alpha)	STRING	Specifies the object in interaction-search-parameters to define the constraint search method.
penalty (beta) [optional]	SUB OBJECT	See linked documentation
offset [optional] (alpha)	true\|false	A tied constraint property if true will use a formulation that approximately maintains gap distance. If false, the tied constraint formulation will not maintain gap distances under rotation, but is less expensive to compute.	true

7.5.2.1 penalty (beta)

Options for penalty enforcement of a boundary condition or other type of constraint. When penalty values are calculated from a dimensionless scale using material properties and element size on two sides of a material or contact interface, the smaller of the two values is selected.

Name	Type	Description	Default
value (beta)	DOUBLE	The value of the penalty parameter, in the range $[0,\infty)$ , determining how strongly the constraint is enforced. The precise interpretation of this value depends on the choice of the parameter dimensionless, whose documentation provides a more detailed discussion. Note that the default value assumes that dimensionless is also set to its default value of true.	1e1
dimensionless (beta)	true\|false	If this parameter is true, then the penalty value is interpreted as the dimensionless constant $C$ in the formula $\beta = CEh^{c-2}$ , where $E$ is a scalar estimate of the material stiffness (i.e., the Young's modulus in elasticity or the thermal conductivity in heat conduction), $h$ is a measure of element size (with units of length), and $c$ is the co-dimension of the constrained set, i.e., 0 for volumes, 1 for surfaces, 2 for curves, or 3 for points. If this parameter is false, then the penalty value is instead interpreted as the dimensional value of $\beta$ directly. The dimensionless option is recommended for most use cases. To interpret the dimensionless penalty value for the common case of constrained boundaries and interfaces ( $c=1$ ) in elasticity, it is roughly the ratio of a single element's change in length under a given tensile load to the error allowed in the consraint. Note that, for any positive value, the constraint error will go to zero as the mesh is refined, since the specimen's overall change in length is distributed over more elements. Selecting too large of a penalty value makes the discrete problem harder to solve. The default value represents a good balance between accuracy and efficiency for most practical applications, but higher values may be appropriate for certain situations, such as calibrating material models with single-element patch tests.	true

7.5.3 material_interface (alpha)

Name	Type	Description	Default
interface (alpha)	STRING	The label of the interaction in the geometry/interactions array.
region_search_method [optional] (alpha)	STRING	The search paramaters to use.
penalty (beta) [optional]	SUB OBJECT	See linked documentation

Example Usage:
material_interface: { interface: "all_interfaces", penalty: {value: 28000000000, dimensionless: false} }

7.5.3.1 penalty (beta)

Options for penalty enforcement of a boundary condition or other type of constraint. When penalty values are calculated from a dimensionless scale using material properties and element size on two sides of a material or contact interface, the smaller of the two values is selected.

Name	Type	Description	Default
value (beta)	DOUBLE	The value of the penalty parameter, in the range $[0,\infty)$ , determining how strongly the constraint is enforced. The precise interpretation of this value depends on the choice of the parameter dimensionless, whose documentation provides a more detailed discussion. Note that the default value assumes that dimensionless is also set to its default value of true.	1e1
dimensionless (beta)	true\|false	If this parameter is true, then the penalty value is interpreted as the dimensionless constant $C$ in the formula $\beta = CEh^{c-2}$ , where $E$ is a scalar estimate of the material stiffness (i.e., the Young's modulus in elasticity or the thermal conductivity in heat conduction), $h$ is a measure of element size (with units of length), and $c$ is the co-dimension of the constrained set, i.e., 0 for volumes, 1 for surfaces, 2 for curves, or 3 for points. If this parameter is false, then the penalty value is instead interpreted as the dimensional value of $\beta$ directly. The dimensionless option is recommended for most use cases. To interpret the dimensionless penalty value for the common case of constrained boundaries and interfaces ( $c=1$ ) in elasticity, it is roughly the ratio of a single element's change in length under a given tensile load to the error allowed in the consraint. Note that, for any positive value, the constraint error will go to zero as the mesh is refined, since the specimen's overall change in length is distributed over more elements. Selecting too large of a penalty value makes the discrete problem harder to solve. The default value represents a good balance between accuracy and efficiency for most practical applications, but higher values may be appropriate for certain situations, such as calibrating material models with single-element patch tests.	true

7.6 interaction_search_parameters (beta)

Each object in the interaction search definitions array defines search parameters to be used in an interaction. Currently the supported search definitions is a sensor-based layout.

Name	Type	Description	Default
label (beta)	STRING	User defined identifier for this interaction search definition.
sensor_based (beta)	SUB OBJECT	See linked documentation

7.6.1 sensor_based (beta)

Defines properties for sensor-based interaction search method. The layout of sensors is determined by the quadrature rule specified in the material interface or tied constraint using these search parameters. For each sensor (quadrature point) on the source surface, the nearest point is found on the target surface using the given parameters.

Name	Type	Description	Default
max_iterations (beta)	NONNEGATIVE INTEGER	Specifies the maximum iterations for the search.	10
relative_tolerance (beta)	DOUBLE	Specifies the relative search tolerance.	1e-8
bounding_box_extension (beta)	DOUBLE	Specifies the extension of the bounding box for the interaction search.	1e-3

7.7 interaction_properties (beta)

The interaction property definition allows the user to define the type of friction and movement that occurs once contact is initiated.

Name	Type	Description	Default
label (beta)	STRING	The user defined identifier for this interaction property definition.
frictionless (beta) \| coulomb_friction (beta)	SUB OBJECT \| SUB OBJECT	One of the given keywords must be defined to specify the class of interaction property

7.7.1 frictionless (beta)

A tangential interaction property, signifying no friction will be enforced. This object has no input variables.

Name

Type

Description

Default

7.7.2 coulomb_friction (beta)

A tangential interaction occurs, governed by the coulomb friction.

Name		Type		Description		Default
coefficient_with_regularization (beta)		SUB OBJECT		Defines how the friction is described.

7.7.2.1 coefficient_with_regularization (beta)

A constant friction coefficient is applied with regularization.

Name	Type	Description	Default
friction_coefficient (beta)	DOUBLE	Friction coefficient.
regularization_velocity (beta)	DOUBLE	The friction_coefficient is multiplied by a regularization factor. The regularization factor is zero when the tangential velocity is zero. It monotomically increases and reaches to one when the magnitude of the tangential velocity becomes regularization_velocity. regularization_velocity can be interpreted as the maximum slip velocity allowed during what should nominally be static friction.

contents ← prev up next →

1	An Overview of Coreform IGA
2	General Terminology
3	iga
4	procedures (release)
5	flex_ models (release)
6	solid_ mechanics_ definitions (release)
7	heat_ transfer_ definitions (alpha)
8	structural_ modal_ analysis_ definitions (alpha)
9	materials (release)
10	time_ steppers (release)
11	nonlinear_ equation_ solvers (beta)
12	linear_ equation_ solvers (release)
13	functions (release)
14	intervals (release)

7.1	boundary_ conditions (alpha)
7.2	load_ conditions (alpha)
7.3	outputs (alpha)
7.4	probes (alpha)
7.5	interactions (alpha)
7.6	interaction_ search_ parameters (beta)
7.7	interaction_ properties (beta)