Source code for rolland.components
"""Defines required superstructure components.
.. autosummary::
:toctree: components
Rail
RailRoughness
DiscrPad
ContPad
Sleeper
Slab
Ballast
Wheel
WheelRoughness
WheelGreensfunc
"""
from traitlets import Float, HasTraits, List, Tuple, Unicode
from traittypes import Array
[docs]
class Rail(HasTraits):
r"""Rail Class.
Defines a rail with certain properties. UIC 60 rail is usually used as default rail.
.. hint:: A set of predefined rail instances is available in the `database` module.
Attributes
----------
rl_geo : list of tuple of float
Rail outline coordinates :math:`[m]`. TODO: Define coordinate system!
E : float
Young's modulus of rail :math:`[Pa]`.
G : float
Shear modulus of rail :math:`[Pa]`.
nu : float
Poisson's ratio of rail :math:`[-]`.
kap : list of float
Timoshenko shear correction factor (vertical, lateral) :math:`[-]`.
mr : float
Rail mass per unit length :math:`[kg/m]`.
rho : float
Density of rail :math:`[kg/m^3]`.
etar : float
Rail loss factor :math:`[-]`.
fresr : float
Rail resonance frequency :math:`[Hz]`.
dr : float
Rail damping coefficient (viscous) :math:`[Ns/m]`.
gamr : list of float
Coordinates of rail shear center :math:`[m]`.
epsr : list of float
Coordinates of center of gravity :math:`[m]`.
Iyr : float
Area moment of inertia of rail around y-axis :math:`[m^4]`.
Izr : float
Area moment of inertia of rail around z-axis :math:`[m^4]`.
Itr : float
Torsional constant of rail :math:`[m^4]`.
Ipr : float
Polar moment of inertia of rail :math:`[m^4]`.
Ar : float
Cross-sectional area of rail :math:`[m^2]`.
Asr : float
Surface area per unit length of rail :math:`[m^2/m]`.
Vr : float
Volume per unit length of rail :math:`[m^3/m]`.
"""
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]
class RailRoughness(HasTraits):
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 containing two lists of float
Rail roughness spectrum :math:`[f, m]`.
"""
r_rough = Tuple(List(Float()), List(Float()))
[docs]
class DiscrPad(HasTraits):
r"""Discrete Pad Class.
Contains the properties of a discrete pad.
Attributes
----------
sp : list of float
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 of float
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 of float
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(), default_value=[0.0, 0.0], maxlen=2)
wdthp = Float()
etap = Float()
fresp = List(Float(), default_value=[0.0, 0.0], maxlen=2)
dp = List(Float(), default_value=[0.0, 0.0], maxlen=2)
[docs]
class ContPad(HasTraits):
r"""Cont Pad Class.
Contains the properties of a continuous pad.
Attributes
----------
sp : list of float
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 of float
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 of float
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(), default_value=[0.0, 0.0], maxlen=2)
etap = Float()
fresp = List(Float(), default_value=[0.0, 0.0], maxlen=2)
dp = List(Float(), default_value=[0.0, 0.0], maxlen=2)
[docs]
class Sleeper(HasTraits):
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()
Bs = Float()
ls = Float()
wdths = Float()
[docs]
class Slab(HasTraits):
r"""Slab class."""
# Slab mass per unit length [kg/m]
ms = Float()
# Slab depth [m]
ls = Float()
[docs]
class Ballast(HasTraits):
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 of float
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 of float
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 of float
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(), default_value=[0.0, 0.0], maxlen=2)
etab = Float()
fresb = List(Float(), default_value=[0.0, 0.0], maxlen=2)
db = List(Float(), default_value=[0.0, 0.0], maxlen=2)
[docs]
class Wheel(HasTraits):
r"""Wheel Class.
Contains the properties of a wheel.
Attributes
----------
w_geo_cross_sec : list of tuple of 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 of tuple of 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 = Unicode()
w_geo = List(Tuple(Float(), Float()))
mw = Float()
mw_red = Float()
rw = Float()
[docs]
class WheelRoughness(HasTraits):
r"""Wheel Roughness Class.
Contains a wheel roughness spectrum in frequency domain.
Attributes
----------
w_rough : tuple of two lists of float
Wheel roughness spectrum :math:`[f, m]`.
"""
w_rough = Tuple(List(Float()), List(Float()))
[docs]
class WheelGreensfunc(HasTraits):
r"""Wheel Greens Function Class.
Contains the Green's function of a wheel.
Attributes
----------
w_gf : numpy.ndarray
Green's function data. Contains the response of the wheel to a unit impulse at
multiple points :math:`[m/N]`.
w_gf_freq : numpy.ndarray
Frequency values of the Green's function :math:`[Hz]`.
"""
w_gf = Array()
w_gf_freq = Array()
