Mechanics

Mechanical realizations shared by the engineering packages: the spring and damper between two coordinates.

SpringDamperInteraction(label, *, target, states=('x1', 'x2'), stiffness='k', damping='b', divisor=None)

Bases: GradientInteraction

Linear spring and damper between two coordinates x1 and x2 of order 2 of one element.

The spring is the gradient of the energy k (x1 - x2)^2 / 2, and the damper adds -b (x1' - x2') to the first coordinate and its opposite to the second, both divided by the divisor of every coordinate, such as its own mass. The stiffness and the damping are named parameters of the element.

Parameters:

Name	Type	Description	Default
label	str	The label of the interaction.	required
target	Annotated[str, RoleSpec()]	The path of the element with the two coordinates.	required
states	Sequence[str]	The names of the two coordinates.	('x1', 'x2')
stiffness	str	The name of the parameter of the stiffness k.	'k'
damping	str	The name of the parameter of the damping b.	'b'
divisor	str | Callable[[SimpleNamespace], object] | Mapping[str, str] | None	The divisor of both coordinates, or a mapping from every coordinate to its own divisor.	None

Raises:

Type	Description
ValidationError	The states are not two names, the stiffness or the damping is not a name, or a divisor is invalid.

Examples:

>>> from skcomplex.models.engineering.common.mechanics import SpringDamperInteraction
>>> SpringDamperInteraction('suspension', target='car', states=('y1', 'y2')).stiffness
'k'

Source code in src/skcomplex/models/engineering/common/mechanics/_spring_damper.py

def __init__(
    self,
    label: str,
    *,
    target: Annotated[str, RoleSpec()],
    states: Sequence[str] = ('x1', 'x2'),
    stiffness: str = 'k',
    damping: str = 'b',
    divisor: str | Callable[[SimpleNamespace], object] | Mapping[str, str] | None = None,
) -> None:
    super().__init__(label, target=target, states=states, divisor=divisor)
    self.stiffness = stiffness
    self.damping = damping