rolland.methods.analytical.TSDiscr2LSupp¶

class rolland.methods.analytical.TSDiscr2LSupp(*args, **kwargs)[source]¶

Bases: TBDiscr

Method for discrete ballasted track according to Thompson [1].

Utilizes a double-layer support with discrete track properties, applying Timoshenko beam theory. The excitation is a non-moving sound source. The corresponding method calculates the track’s mobility for the postions specified.

Caution

This method is an implementation of Thompson [1] which is a modified version of Heckl [5]. Theoretically, the results should be identical, but Heckl’s work contains the following mistakes, which lead to incorrect results:

Missing negativ sign in the definition of the decaying wave number (Eq. 2b).
Shear modulus \(G\) needs to be substituted by \(G * \kappa\)

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

track¶

Track instance.

Type:: DiscrSlabSingleRailTrack

omega_0¶

Resonance frequency rail <–> foundation \([Hz]\).

Type:: float

omega_1¶

Resonance frequency ballast <–> slab \([Hz]\).

Type:: float

omega_2¶

Resonance frequency rail <–> slab \([Hz]\).

Type:: float

validate_method()[source]¶: Validate method.

compute_mobility()[source]¶

Compute the mobility of the track.

This method calculates the mobility of the track using the given parameters and the analytical solution for a discrete ballasted track.

mobility¶

Calculated mobility of the track \([m/N]\).

Type:: numpy.ndarray