SSPQuadElement

SSPQuadElement(ndof: int, material: Material, Type: str, Thickness: float, b1: float = 0.0, b2: float = 0.0, **kwargs)

Bases: Element

Stabilized single-point quadrilateral continuum element for 2D models.

This four-node element represents plane-strain or plane-stress continua with 2 translational DOFs per node. It requires a 2D nDMaterial and an explicit out-of-plane thickness.

Tcl form

element SSPquad <tag> <n1> <n2> <n3> <n4> <matTag> <Type> <Thickness> [<b1> <b2>]

Note

Type must be either PlaneStrain or PlaneStress.
Nodes should be ordered counter-clockwise in the element plane.
Body forces are constant in global coordinates and omitted when zero.

Attributes:

Name	Type	Description
`Type`		Plane-stress or plane-strain formulation flag.
`Thickness`		Out-of-plane thickness used by the element formulation.
`b1`		Constant body force in the global x-direction.
`b2`		Constant body force in the global y-direction.

Example

from femora.core.model import Model

model = Model()
mat = model.material.nd.elastic_isotropic(
    user_name="Soil2D",
    E=3.0e7,
    nu=0.3,
    rho=1900.0,
)
ele = model.element.quad.ssp(
    ndof=2,
    material=mat,
    Type="PlaneStrain",
    Thickness=1.0,
)
print(ele.tag)

Create an SSPQuadElement with validated material and geometry inputs.

Parameters:

Name	Type	Description	Default
`ndof`	`int`	Number of DOFs per node. Must be 2 for this element.	required
`material`	`Material`	Managed 2D `nDMaterial` assigned to the quadrilateral.	required
`Type`	`str`	`PlaneStrain` or `PlaneStress` formulation flag.	required
`Thickness`	`float`	Element thickness in the out-of-plane direction.	required
`b1`	`float`	Constant body force in the global x-direction.	`0.0`
`b2`	`float`	Constant body force in the global y-direction.	`0.0`
`**kwargs`		Additional element parameters stored on the base element.	`{}`

Raises:

Type	Description
`ValueError`	If the material is incompatible, if `ndof` is not 2, or if any parameter is missing or invalid.