rolland.methods.analytical.TBDiscr

class rolland.methods.analytical.TBDiscr(*args, **kwargs)

Bases: AnalyticalMethods

Base class for analytical solutions of a discrete single rail track.

f

Excitation frequencies \([Hz]\).

Type:

numpy.ndarray

force

Force amplitude corresponding to the excitation frequencies \([N]\).

Type:

numpy.ndarray

x

Distances to the excitation point \([m]\).

Type:

float or list

x_excit

Excitation point \([m]\).

Type:

numpy.ndarray

abstractmethod validate_method()

Validate method.

calc_greens_func(xm, xn, k_p, k_d, f_p, f_d)

Calculate Greens function of free Timoshenko Beam (eq. 3.69).

Parameters:

• xm (numpy.ndarray) – Positions of the first set of points \([m]\).

• xn (numpy.ndarray) – Positions of the second set of points \([m]\).

• k_p (numpy.ndarray) – Wave number of propagating wave \([1/m]\).

• k_d (numpy.ndarray) – Wave number of decaying wave \([1/m]\).

• f_p (numpy.ndarray) – Factor for propagating wave \([-]\).

• f_d (numpy.ndarray) – Factor for decaying wave \([-]\).

Returns:

Calculated Greens function.

Return type:

numpy.ndarray

compute_mobility_common(track, ms, sb, etab)

Compute common mobility for 1-layer and 2-layer support.

Parameters:

• track (object) – Track instance containing rail and pad properties.

• ms (float) – Mass per unit length of the sleeper or slab [kg/m].

• sb (float) – Stiffness of the ballast [N/m^2].

• etab (float) – Damping coefficient of the ballast.

f_0

Resonance frequency rail <–> pads [Hz].

Type:

float

f_1

Resonance frequency ballast <–> sleepers [Hz].

Type:

float

f_2

Resonance frequency rail <–> sleepers [Hz].

Type:

float

mobility

Calculated mobility of the track [m/N].

Type:

numpy.ndarray