Constitutive Behavior#

The constitutive layer describes what a material does, independently of the structural model that uses it. A structural model holds a MaterialBehaviorMap binding physics channels to behaviors.

Protocols#

class sgio.model.Model(*args, **kwargs)#

Protocol shared by legacy model-like objects.

get(name: str)#

Get model parameter (property) given a name.

class sgio.model.ConstitutiveBehaviorProtocol(*args, **kwargs)#

Protocol for stateless or stateful constitutive behaviors.

export_payload() → Any#

Return the payload currently backing this behavior.

property descriptor: ConstitutiveBehaviorDescriptor#

Return the static behavior descriptor.

class sgio.model.HistoryDependentBehaviorProtocol(*args, **kwargs)#

Protocol for future history-dependent constitutive behaviors.

describe_consistent_tangent() → str#

Describe the tangent quantity exposed by the behavior.

describe_update_rule() → str#

Describe the update law boundary used by the behavior.

initialize_history_state() → dict[str, Any]#

Return one initialized history-state payload.

Behaviors and Descriptors#

class sgio.model.LinearElasticConstitutiveBehavior(payload: LinearElasticBehavior)#

Bases: object

Adapter exposing current linear elasticity through the generic behavior seam.

Parameters:

payload (LinearElasticBehavior) – Linear-elastic payload snapshot.

export_payload() → LinearElasticBehavior#

Return the wrapped linear-elastic payload.

property descriptor: ConstitutiveBehaviorDescriptor#

Return the linear-elastic behavior descriptor.

class sgio.model.ConstitutiveBehaviorDescriptor(name: str, channels: tuple[PhysicsChannel, ...], is_stateful: bool, inputs: tuple[BehaviorVariable, ...] = (), outputs: tuple[BehaviorVariable, ...] = (), tangent_outputs: tuple[BehaviorVariable, ...] = (), state_variables: tuple[BehaviorVariable, ...] = (), notes: str = '')#

Static descriptor of one constitutive behavior family.

Parameters:

  • name (str) – Behavior family name.

  • channels (tuple[PhysicsChannel, ...]) – Physics channels covered by the behavior.

  • is_stateful (bool) – Whether the behavior carries history variables.

  • inputs (tuple[BehaviorVariable, ...], optional) – Input variables.

  • outputs (tuple[BehaviorVariable, ...], optional) – Output variables.

  • tangent_outputs (tuple[BehaviorVariable, ...], optional) – Tangent outputs or linearization products.

  • state_variables (tuple[BehaviorVariable, ...], optional) – History variables used by the behavior.

  • notes (str, optional) – Additional notes about the behavior boundary.

class sgio.model.MaterialBehaviorMap(mechanical: ~sgio.model.constitutive.ChannelBehaviorSlot = <factory>, thermal: ~sgio.model.constitutive.ChannelBehaviorSlot = <factory>, electrical: ~sgio.model.constitutive.ChannelBehaviorSlot = <factory>, magnetic: ~sgio.model.constitutive.ChannelBehaviorSlot = <factory>, optical: ~sgio.model.constitutive.ChannelBehaviorSlot = <factory>, couplings: tuple[~sgio.model.constitutive.ChannelCouplingDescriptor, ...] = ())#

Container reserving per-channel constitutive behavior slots.

Parameters:
get_slot(channel: PhysicsChannel) → ChannelBehaviorSlot#

Return one channel slot by enum key.

class sgio.model.BehaviorVariable(name: str, channel: PhysicsChannel, role: BehaviorVariableRole, description: str = '')#

One named constitutive variable used by a behavior descriptor.

Parameters:

  • name (str) – Variable name.

  • channel (PhysicsChannel) – Owning physics channel.

  • role (BehaviorVariableRole) – Variable role.

  • description (str, optional) – Human-readable description.

class sgio.model.ChannelBehaviorSlot(channel: PhysicsChannel, behavior: ConstitutiveBehaviorProtocol | None = None, properties: Any | None = None)#

One extensibility slot for a single physics channel.

Parameters:

  • channel (PhysicsChannel) – Slot channel.

  • behavior (ConstitutiveBehaviorProtocol or None, optional) – Attached behavior implementation.

  • properties (object or None, optional) – Auxiliary channel properties not yet promoted to full behaviors.

class sgio.model.ChannelCouplingDescriptor(source: PhysicsChannel, target: PhysicsChannel, description: str = '')#

Descriptor for one cross-channel coupling relation.

Parameters:

  • source (PhysicsChannel) – Driving channel.

  • target (PhysicsChannel) – Driven channel.

  • description (str, optional) – Human-readable description of the coupling.

class sgio.model.TensorComponent(row: int, column: int)#

Typed material tensor/matrix component selector.

Parameters:

  • row (int) – One-based row index or tensor index.

  • column (int) – One-based column index or tensor index.

to_matrix_indices() → tuple[int, int]#

Return zero-based matrix indices.

to_voigt_index() → int#

Return the zero-based Voigt index for thermal-expansion access.

Enumerations#

class sgio.model.PhysicsChannel(value)#

Supported constitutive physics channels.

ELECTRICAL = 'electrical'#
MAGNETIC = 'magnetic'#
MECHANICAL = 'mechanical'#
OPTICAL = 'optical'#
THERMAL = 'thermal'#
class sgio.model.BehaviorVariableRole(value)#

Role of one constitutive variable within a behavior descriptor.

INPUT = 'input'#
OUTPUT = 'output'#
STATE = 'state'#
TANGENT = 'tangent'#
class sgio.model.ElasticInputType(value)#

Typed elastic-input selector for material APIs.

classmethod from_value(input_type: ElasticInputType | str | int) → ElasticInputType#

Normalize legacy elastic input tokens into one enum value.

Parameters:

input_type (ElasticInputType or str or int) – Legacy or typed elastic input selector.

Returns:

Normalized enum value.

Return type:

ElasticInputType

ANISOTROPIC = 'anisotropic'#
AUTO = ''#
COMPLIANCE = 'compliance'#
ENGINEERING = 'engineering'#
ISOTROPIC = 'isotropic'#
LAMINA = 'lamina'#
ORTHOTROPIC = 'orthotropic'#
STIFFNESS = 'stiffness'#
TRANSVERSE_ISOTROPIC = 'transverse_isotropic'#
class sgio.model.MatrixKind(value)#

Typed selector for material matrix views.

COMPLIANCE = 'compliance'#
STIFFNESS = 'stiffness'#
class sgio.model.SectionMatrixKind(value)#

Typed selector for beam/shell section-result matrices.

CLASSICAL_COMPLIANCE = 'classical_compliance'#
CLASSICAL_STIFFNESS = 'classical_stiffness'#
COMPLIANCE = 'compliance'#
GEOMETRIC_STIFFNESS = 'geometric_stiffness'#
MASS = 'mass'#
MASS_CENTER = 'mass_center'#
STIFFNESS = 'stiffness'#
class sgio.model.SectionAxis(value)#

Typed selector for section-result principal axes.

BENDING = 'bending'#
INERTIAL = 'inertial'#
SHEAR = 'shear'#
class sgio.model.SectionCenter(value)#

Typed selector for section-result center locations.

MASS = 'mass'#
SHEAR = 'shear'#
TENSION = 'tension'#
class sgio.model.LocationType(value)#

Valid location types for state data.

ELEMENT = 'element'#
ELEMENT_NODE = 'element_node'#
NODE = 'node'#

Helper Functions#

sgio.model.getModelDim(model: str) → int#

Infer structural-model dimension from a legacy model label.

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