Besides an improved running dynamical design of railway vehicle, the modelling extensions also open the new field of acoustics that has been beyond the capabilities of the multibodymethodology so far.
In addition to the approach presented above, structural dynamics models with high-frequency modes up to 6 kHz for the wheel-sets and even 10 kHz for the rails are taken into account together with appropriate excitation mechanism such as surface roughness or mode coupling.
On this basis a post-processing procedure of the multibody simulation results was defined that yields the structure-borne-noise level at the surface of the observed component. The figure below shows exemplary results of the rolling noise of a wheel, excited by tracks with different surface roughness. Although the acoustic post-processing here is applied at the wheel/rail interface, it is actually a very general procedure that as well is valid e.g. for machinery acoustics.
In the near future the post-processing procedure will be extended to evaluate the air-borne-noise level e.g. in a distance of 7.5m when a train passes by.
Exemplary comparison of the structure-borne-noise level: the same wheel, running on two different tracks.