pressure_depend_multi_yield

Pressure-dependent multi-yield soil plasticity (OpenSees PressureDependMultiYield).

Attributes

all `module-attribute`

__all__ = ['PressureDependMultiYieldMaterial']

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.

PressureDependMultiYieldMaterial

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

Bases: Material

Layered-yield soil plasticity with evolving strength versus confining stress.

This model targets saturated soil elements that require confining-stress dependent stiffness together with nested yield surfaces or a user-defined backbone to capture nonlinear soil response. Parameter names follow the OpenSees command vocabulary directly.

Tcl form

nDMaterial PressureDependMultiYield <tag> nd rho Gr Br ... liquefac3 noYieldSurf [gamma Gs ...] e cs1 cs2 cs3 pa c; #

Note

nd must be 2 for plane strain or 3 for three-dimensional use.
Positive noYieldSurf requests auto-generated nested yield surfaces.
Negative noYieldSurf switches to user-defined backbone input with abs(noYieldSurf) (gamma, Gs) pairs.
Supplied pairs may be a flat list [g1, Gs1, ...] or a list of (gamma, Gs) tuples.
Unrecognized keyword arguments are ignored for compatibility.

Example

from femora.core.model import Model

model = Model()
mat = model.material.nd.pressure_depend_multi_yield(
    user_name="profiled_soil",
    nd=3,
    rho=2.0,
    refShearModul=1.0e5,
    refBulkModul=3.0e5,
    frictionAng=37.0,
    peakShearStra=0.1,
    refPress=80.0,
    pressDependCoe=0.5,
    PTAng=27.0,
    contrac=0.05,
    dilat1=0.6,
    dilat2=3.0,
    liquefac1=5.0,
    liquefac2=0.003,
    liquefac3=1.0,
    noYieldSurf=20,
)
print(mat.tag)

Construct the material from keyword arguments matching OpenSees naming.

Parameters:

Name	Type	Description	Default
`user_name`	`str`	Label placed in the trailing Tcl comment once managed.	`'Unnamed'`
`nd`		Spatial dimension flag, either `2` or `3`.	required
`rho`		Saturated mass density, strictly positive in model units.	required
`refShearModul`		Reference low-strain shear modulus at `refPress`.	required
`refBulkModul`		Reference bulk modulus at `refPress`.	required
`frictionAng`		Peak friction angle in degrees.	required
`peakShearStra`		Octahedral shear strain at peak strength, strictly positive.	required
`refPress`		Reference mean effective stress, strictly positive.	required
`pressDependCoe`		Non-negative confinement dependence coefficient.	required
`PTAng`		Phase-transformation angle in degrees.	required
`contrac`		Contractive plasticity parameter.	required
`dilat1`		First dilatancy parameter.	required
`dilat2`		Second dilatancy parameter.	required
`liquefac1`		Liquefaction parameter 1.	required
`liquefac2`		Liquefaction parameter 2.	required
`liquefac3`		Liquefaction parameter 3.	required
`noYieldSurf`		Surface count or negative custom-backbone selector.	required
`pairs`		Custom backbone data required when `noYieldSurf < 0`.	required
`e`		Optional void ratio, default `0.6`.	required
`cs1`		Optional critical-state coefficient, default `0.9`.	required
`cs2`		Optional critical-state coefficient, default `0.02`.	required
`cs3`		Optional critical-state coefficient, default `0.7`.	required
`pa`		Optional atmospheric or reference pressure, default `101.0`.	required
`c`		Optional cohesion-like intercept, default `0.3`.	required

Raises:

Type	Description
`ValueError`	If a required Tcl argument is missing.
`ValueError`	If a numeric Tcl argument cannot be converted correctly.
`ValueError`	If any validated value falls outside the supported range.

Methods:

to_tcl

to_tcl() -> str

Flatten parameters into the long OpenSees PressureDependMultiYield line.

Returns:

Name	Type	Description
`str`	`str`	Tcl text beginning with `nDMaterial PressureDependMultiYield`
	`str`	followed by the primary soil parameters, `noYieldSurf`, optional
	`str`	backbone scalars, and the trailing `e cs1 cs2 cs3 pa c` block.

Raises:

Type	Description
`ValueError`	If the material is not yet tagged by a manager.

updateMaterialStage

updateMaterialStage(state: str) -> str

Return Tcl that toggles elastic staging for staged analysis workflows.

Parameters:

Name	Type	Description	Default
`state`	`str`	`"elastic"` maps to stage `0` and `"plastic"` maps to stage `1`. Other strings yield an empty return.	required

Returns:

Name	Type	Description
`str`	`str`	An `updateMaterialStage` command or an empty string.

Raises:

Type	Description
`ValueError`	If the material tag is still `None`.

pressure_depend_multi_yield