An efficient model for predicting the sound radiation from a railway rail accounting for cross-section deformation

Abstract

The track is the main contributor to railway rolling noise below 2 kHz. In this frequency range it is usually acceptable to represent the rail vibration using a Timoshenko beam. At higher frequencies, however, cross-section deformation occurs in the rail, which requires more complex track models. In this paper a vibroacoustic 2.5D Finite Element and Boundary Element model of a continuously supported rail is implemented for studying the effect of cross-section deformation on sound radiation. A novel interpolation strategy is developed to significantly reduce the solution time by interpolating element coefficient vectors. Results are calculated for vertical or lateral excitation applied to the rail head and comparisons are made with a Timoshenko beam model in which the cross-section remains undeformed. For vertical excitation, the sound power from both models is identical below 3 kHz, while for lateral excitation, the Timoshenko beam has differences of up to 25 dB below 200 Hz owing to the missing rail torsion and foundation eccentricity. Above 3 kHz for vertical excitation and from 1 kHz for lateral excitation, higher-order waves contribute to the sound power, causing an underestimation of up to 15 dB if the cross-section deformation is neglected. The calculated transfer functions of rail sound power per unit squared force are incorporated in a rolling noise prediction model that includes vertical and lateral dynamics. The results show that the Timoshenko beam rail underestimates the rail sound power by up to 5 dB in comparison with the 2.5D rail model in one-third octave bands.

More information

Identifiers

ORCID for Christopher Knuth: orcid.org/0000-0003-4995-2179

ORCID for Giacomo Squicciarini: orcid.org/0000-0003-2437-6398

ORCID for David Thompson: orcid.org/0000-0002-7964-5906

Catalogue record

Export record

Altmetrics