"""Defines required superstructure components.
.. autosummary::
:toctree: components
Rail
RailRoughness
DiscrPad
ContPad
Sleeper
Slab
Ballast
Wheel
WheelRoughness
WheelGreensfunc
"""
from dataclasses import dataclass, field
from numpy import ndarray
[docs]
@dataclass(kw_only=True)
class Rail:
r"""Represents a rail with specific physical and geometric properties.
UIC 60 rail is typically used as the default rail profile.
.. hint::
A set of predefined rail instances is available in the :mod:`database` module.
Attributes
----------
rl_geo : list[tuple[float, float]]
Rail outline coordinates in :math:`[\mathrm{m}]`.
E : float
Young's modulus of rail in :math:`[\mathrm{Pa}]`.
G : float
Shear modulus of rail in :math:`[\mathrm{Pa}]`.
nu : float
Poisson's ratio of rail :math:`[-]`.
kap : list[float]
Timoshenko shear correction factor (vertical, lateral) :math:`[-]`.
mr : float
Rail mass per unit length in :math:`[\mathrm{kg/m}]`.
rho : float
Density of rail in :math:`[\mathrm{kg/m^3}]`.
etar : float
Rail loss factor :math:`[-]`.
fresr : float
Rail resonance frequency in :math:`[\mathrm{Hz}]`.
dr : float
Rail damping coefficient (viscous) in :math:`[\mathrm{Ns/m}]`.
gamr : list[float]
Coordinates of rail shear center in :math:`[\mathrm{m}]`.
epsr : list[float]
Coordinates of center of gravity in :math:`[\mathrm{m}]`.
Iyr : float
Area moment of inertia of rail around y-axis in :math:`[\mathrm{m^4}]`.
Izr : float
Area moment of inertia of rail around z-axis in :math:`[\mathrm{m^4}]`.
Itr : float
Torsional constant of rail in :math:`[\mathrm{m^4}]`.
Ipr : float
Polar moment of inertia of rail in :math:`[\mathrm{m^4}]`.
Ar : float
Cross-sectional area of rail in :math:`[\mathrm{m^2}]`.
Asr : float
Surface area per unit length of rail in :math:`[\mathrm{m^2/m}]`.
Vr : float
Volume per unit length of rail in :math:`[\mathrm{m^3/m}]`.
Examples
--------
Create a custom rail profile:
>>> custom_rail = Rail(
... rl_geo=[(0.0, 0.0), (0.075, 0.0)],
... E=2.1e11,
... G=8.1e10,
... nu=0.3,
... kap=[0.4, 0.4],
... mr=60.0,
... # ... specify remaining parameters ...
... )
"""
rl_geo: list[tuple[float, float]]
E: float
G: float
nu: float
kap: list[float]
mr: float
rho: float
etar: float
fresr: float
dr: float
gamr: list[float]
epsr: list[float]
Iyr: float
Izr: float
Itr: float
Ipr: float
Ar: float
Asr: float
Vr: float
[docs]
@dataclass(kw_only=True)
class RailRoughness:
r"""Rail Roughness Class.
Contains a rail roughness spectrum in frequency domain, which can later be used to calculate the
rail roughness along the track.
Attributes
----------
r_rough : tuple[list[float], list[float]]
Rail roughness spectrum :math:`[f, m]`.
"""
r_rough: tuple[list[float], list[float]]
[docs]
@dataclass(kw_only=True)
class DiscrPad:
r"""Discrete Pad Class.
Contains the properties of a discrete pad.
Attributes
----------
sp : list[float], default=[0.0, 0.0]
Vertical/lateral pad stiffness (total value) :math:`[N/m]`. Lateral value can be set to zero
when lateral rail deflections are omitted.
wdthp : float
Pad width in x-direction :math:`[m]`.
etap : float
Pad loss factor :math:`[-]`.
fresp : list[float], default=[0.0, 0.0]
Vertical/lateral pad resonance frequencies [Hz]. This frequency is needed for calculating
the viscous damping coefficient if it is not provided. Lateral value can be set to zero when
lateral rail deflections are omitted.
dp : list[float], default=[0.0, 0.0]
Vertical/lateral pad damping coefficient (viscous) :math:`[Ns/m]`. Lateral value can be set
to zero when lateral rail deflections are omitted.
"""
sp: list[float] = field(default_factory=lambda: [0.0, 0.0], metadata={"default_repr": "[0.0, 0.0]"})
wdthp: float = 0.0
etap: float= 0
fresp: list[float] = field(default_factory=lambda: [0.0, 0.0], metadata={"default_repr": "[0.0, 0.0]"})
dp: list[float] = field(default_factory=lambda: [0.0, 0.0], metadata={"default_repr": "[0.0, 0.0]"})
[docs]
@dataclass(kw_only=True)
class ContPad:
r"""Cont Pad Class.
Contains the properties of a continuous pad.
Attributes
----------
sp : list[float], default=[0.0, 0.0]
Vertical/lateral pad stiffness (per meter) :math:`[N/m^2]`. Lateral value can be set to zero
when lateral rail deflections are omitted.
etap : float
Pad loss factor :math:`[-]`.
fresp : list[float], default=[0.0, 0.0]
Vertical/lateral pad resonance frequencies :math:`[Hz]`. These frequencies are needed for
calculating the viscous damping coefficients if they are not provided. Lateral value can be
set to zero when lateral rail deflections are omitted.
dp : list[float], default=[0.0, 0.0]
Vertical/lateral viscous damping coefficient (per meter) :math:`[Ns/m^2]`. Lateral value can
be set to zero when lateral rail deflections are omitted.
"""
sp: list[float] = field(default_factory=lambda: [0.0, 0.0], metadata={"default_repr": "[0.0, 0.0]"})
etap: float = 0
fresp: list[float] = field(default_factory=lambda: [0.0, 0.0], metadata={"default_repr": "[0.0, 0.0]"})
dp: list[float] = field(default_factory=lambda: [0.0, 0.0], metadata={"default_repr": "[0.0, 0.0]"})
[docs]
@dataclass(kw_only=True)
class Sleeper:
r"""Sleeper Class.
Contains the properties of a sleeper.
Attributes
----------
ms : float
Sleeper mass :math:`[kg]`.
Bs : float
Sleeper bending stiffness :math:`[Nm^2]`.
ls : float
Sleeper length in y-direction :math:`[m]`.
wdths : float
Sleeper width in x-direction :math:`[m]`.
"""
ms: float = 0.0
Bs: float = 0.0
ls: float = 0.0
wdths: float = 0.0
[docs]
@dataclass(kw_only=True)
class Slab:
r"""Slab class.
Contains the properties of the slab.
Attributes
----------
ms : float
Slab mass per unit length :math:`[kg/m]`.
ls : float
Slab depth :math:`[m]`.
"""
ms: float
ls: float = 0.0
[docs]
@dataclass(kw_only=True)
class Ballast:
r"""Ballast Class.
Contains the properties of the ballast.
.. caution::
Properties of the ballast can either be defined as discrete values acting at the
mounting positions or as continuous values acting per meter depending. The values need to be
chosen accordingly to the track type.
Attributes
----------
sb : list[float], default=[0.0, 0.0]
Vertical/lateral ballast stiffness (total value :math:`[N/m]` or per meter :math:`[N/m^2]`).
Lateral value can be set to zero when lateral rail deflections are omitted.
etab : float
Ballast loss factor :math:`[-]`.
fresb : list[float], default=[0.0, 0.0]
Vertical/lateral ballast resonance frequencies :math:`[Hz]`. These frequencies are needed
for calculating the viscous damping coefficients if they are not provided. Lateral value can
be set to zero when lateral rail deflections are omitted.
db : list[float], default=[0.0, 0.0]
Vertical/lateral viscous damping coefficient (per meter) :math:`[Ns/m]`. Lateral value can
be set to zero when lateral rail deflections are omitted.
"""
sb: list[float] = field(default_factory=lambda: [0.0, 0.0], metadata={"default_repr": "[0.0, 0.0]"})
etab: float = 0.0
fresb: list[float] = field(default_factory=lambda: [0.0, 0.0], metadata={"default_repr": "[0.0, 0.0]"})
db: list[float] = field(default_factory=lambda: [0.0, 0.0], metadata={"default_repr": "[0.0, 0.0]"})
[docs]
@dataclass(kw_only=True)
class Wheel:
r"""Wheel Class.
Contains the properties of a wheel.
Attributes
----------
w_geo_cross_sec : list[tuple[float, float]]
Wheel cross-sectional geometry coordinates (y-z plane) :math:`[m]`.
TODO: Define coordinate system
w_prof : str
Wheel running surface profile.
w_geo : list[tuple[float, float]]
Wheel geometry coordinates (x-y plane) :math:`[m]`.
TODO: Define coordinate system
mw : float
Wheel mass :math:`[kg]`.
mw_red : float
Reduced wheel mass :math:`[kg]`. Needed in order to calculate the lateral dynamics
according to :cite:t:`wu2004a`.
rw : float
Wheel radius from the axis of rotation to the contact point :math:`[m]`.
"""
w_geo_cross_sec: list[tuple[float, float]]
w_prof: str
w_geo: list[tuple[float, float]]
mw: float
mw_red: float
rw: float
[docs]
@dataclass(kw_only=True)
class WheelRoughness:
r"""Wheel Roughness Class.
Contains a wheel roughness spectrum in frequency domain.
Attributes
----------
w_rough : tuple[list[float], list[float]]
Wheel roughness spectrum :math:`[f, m]`.
"""
w_rough: tuple[list[float], list[float]]
[docs]
@dataclass(kw_only=True)
class WheelGreensfunc:
r"""Wheel Greens Function Class.
Contains the Green's function of a wheel.
Attributes
----------
w_gf : ndarray
Green's function data. Contains the response of the wheel to a unit impulse at
multiple points :math:`[m/N]`.
w_gf_freq : ndarray
Frequency values of the Green's function :math:`[Hz]`.
"""
w_gf: ndarray
w_gf_freq: ndarray
