The Simulation of Tyre/Road Interaction and Exterior Rolling Noise for Road Surfaces With Transversal Discontinuities

Tyre/road noise is a common problem in modern societies. A particular strong tyre excitation results from driving over transversal discontinuities in the road: e.g. potholes, pavement patching, tram rails, or bridge joints. Due to the transient nature of the excitation, the noise created by driving over these features is characterised by short peaks. While this often only causes a very limited increase in $L_{pAeq,24h}$, $L_{pA,max}$ values at the discontinuity can be several dB higher than for the surrounding uninterrupted road surface. This leads to a higher annoyance of residents living close-by. A majority of the increase in $L_{pA,max}$ stems from the excitation of tyre air cavity resonances. These are normally of minor importance for exterior rolling noise, and are thus typically ignored in simulations. This study is based on a validated tyre/road noise simulation tool for rolling on real, continuous road surfaces. The tool is extended to include the air cavity and the structural-acoustical coupling. Tyre/road interaction is calculated for a tyre rolling over a bridge joint. The outcome of different simulation stages is compared to simulations for rolling over a continuous road surface, simulations for a tyre model without air cavity rolling over the bridge joint, and measurement results.