pressure_independ_multi_yield

Pressure-independent multi-yield soil plasticity (OpenSees PressureIndependMultiYield).

Attributes

all `module-attribute`

__all__ = ['PressureIndependMultiYieldMaterial']

Classes

Material

Material(material_type: str, material_name: str, user_name: str)

Bases: ABC

Abstract base class for manager-owned OpenSees material objects.

Material instances do not self-register and do not assign their own tags. A :class:~femora.core.material_manager.MaterialManager owns lifecycle operations, tag assignment, removal, and retagging for a local model context.

Parameters:

Name	Type	Description	Default
`material_type`	`str`	OpenSees material category (e.g. `'nDMaterial'`).	required
`material_name`	`str`	Concrete OpenSees material name (e.g. `'ElasticIsotropic'`).	required
`user_name`	`str`	User-specified label for this material instance.	required

Attributes:

Name	Type	Description
`tag`	`Optional[int]`	Manager-assigned OpenSees material tag. Remains `None` until this object is added to a :class:`~femora.core.material_manager.MaterialManager`.
`_owner`	`object \| None`	Reference to the owning manager, or `None` when unmanaged.

Methods:

to_tcl `abstractmethod`

to_tcl() -> str

Render the OpenSees material definition command as a Tcl string.

updateMaterialStage

updateMaterialStage(state: str) -> str

Return an updateMaterialStage Tcl command, or empty string.

set_parameter

set_parameter(parameter_name: str, new_value: Union[float, int, str, None] = None, element_tags: Optional[List[int]] = None) -> str

Return a setParameter Tcl command, or empty string.

get_param

get_param(key: str) -> Any

Return the value of a stored parameter by key.

PressureIndependMultiYieldMaterial

PressureIndependMultiYieldMaterial(user_name: str = 'Unnamed', **kwargs: Any)

Bases: Material

Nested-surface plasticity for soils without confining-stress-driven hardening.

Use this nDMaterial when layer strength is specified through reference moduli, cohesion, friction, and optionally a tabular backbone instead of the pressure-dependent coupling used by PressureDependMultiYieldMaterial.

Tcl form

nDMaterial PressureIndependMultiYield <tag> nd rho Gr Br cohesi peakShearStra frictionAng refPress pressDependCoe noYieldSurf [gamma Gs ...]; #

Note

Positive noYieldSurf allocates that many auto-generated surfaces.
Negative noYieldSurf requires pairs with abs(noYieldSurf) backbone points.
frictionAng defaults to 0, refPress defaults to 100, and pressDependCoe defaults to 0.

Attributes:

Name	Type	Description
`params`		Final soil parameters plus optional backbone list.

Example

from femora.core.model import Model

model = Model()
mat = model.material.nd.pressure_independ_multi_yield(
    user_name="pi_soil",
    nd=3,
    rho=2.0,
    refShearModul=1.1e5,
    refBulkModul=3.0e5,
    cohesi=5.0,
    peakShearStra=0.12,
    noYieldSurf=15,
)
print(mat.tag)

Validate soil keyword arguments before storing them for Tcl export.

Parameters:

Name	Type	Description	Default
`user_name`	`str`	Comment annotation and manager registry key.	`'Unnamed'`
`nd`		`2` or `3` dimensional analysis flag.	required
`rho`		Saturated density, strictly positive.	required
`refShearModul`		Reference small-strain shear modulus, strictly positive.	required
`refBulkModul`		Reference bulk modulus, strictly positive.	required
`cohesi`		Apparent cohesion intercept, non-negative.	required
`peakShearStra`		Octahedral shear strain marker for peak strength.	required
`frictionAng`		Friction angle in degrees. Defaults to `0` when omitted.	required
`refPress`		Positive reference mean stress. Defaults to `100`.	required
`pressDependCoe`		Non-negative confinement scaling coefficient.	required
`noYieldSurf`		Surface count or negative backbone selector.	required
`pairs`		Mandatory custom backbone list when `noYieldSurf < 0`.	required

Raises:

Type	Description
`ValueError`	If a required keyword argument is missing.
`ValueError`	If a numeric value cannot be converted correctly.
`ValueError`	If any validated value falls outside the supported range.
`ValueError`	If `pairs` is malformed or invalid when required.

Methods:

to_tcl

to_tcl() -> str

Emit the Tcl declaration with optional backbone tail expansion.

Returns:

Name	Type	Description
`str`	`str`	Tcl line including moduli, cohesion, friction defaults,
	`str`	`noYieldSurf`, and interleaved backbone pairs when applicable.

Raises:

Type	Description
`ValueError`	If the material was not registered with a manager.

updateMaterialStage

updateMaterialStage(state: str) -> str

Construct Tcl for elastic/plastic modulus staging plus inline comment tag.

Parameters:

Name	Type	Description	Default
`state`	`str`	`"elastic"` maps to stage `0` and `"plastic"` maps to stage `1`. Other tokens return blank output.	required

Returns:

Name	Type	Description
`str`	`str`	Tcl with `;# user_name` suffix when a stage matched.

Raises:

Type	Description
`ValueError`	When no tag has been assigned yet.

set_parameter

set_parameter(parameter_name: str, new_value: Optional[float] = None, element_tags: Optional[List[int]] = None) -> str

Build Tcl that updates material parameters element-by-element.

Parameters:

Name	Type	Description	Default
`parameter_name`	`str`	One of `shearModulus`, `bulkModulus`, `cohesion`, `frictionAngle`, or `stressCorrection`.	required
`new_value`	`Optional[float]`	Scalar passed to `-val` for non-stress-correction modes. Ignored for `stressCorrection`.	`None`
`element_tags`	`Optional[List[int]]`	OpenSees element IDs to touch.	`None`

Returns:

Name	Type	Description
`str`	`str`	Multi-line Tcl script suitable for appending to staged analyses.

Raises:

Type	Description
`ValueError`	If `parameter_name` is unsupported.
`ValueError`	If the material lacks a manager-assigned tag.

pressure_independ_multi_yield