Abstract
A total of 15 passenger car tyres have been measured on a selection of SMA-types of road surfaces normally used in Norway, as well as some test surfaces of porous asphalt. The measurements have been done using a CPX-trailer at 50 and 80 km/h.In addition, all the tyres have been measured on 3 different types of surfaces on the drum facilities of TUG in Gdansk/Poland, including an ISO-surface. Measurements of rolling resistance have also been done by TUG. The rolling noise of 40 tyres (including 11 of the tyres used for CPX and drum measurements) has been modelled, using the SPERoN model with 3D texture spectra of some of the Norwegian SMA-surfaces as input data.The aim of the project is to compare the ranking of the tyre/road noise of passenger car tyres on different road surfaces, compared to the ranking on ISO-surface. The preliminary results show that the correlation between drum measurements, modelling and road measurements are poor, when the correlation is based on overall A-levels alone. The reason for this can partly be explained by the fact that the noise excitation mechanisms are quite different for each of the three conditions and that the linear correlation technique is too limited to explain the connection between these mechanisms.The main conclusions from the CPX-measurements results are that the ranking of the tyres are more or less the same on all road surfaces that have been exposed to winter conditions. The spread in the levels are in the order of 3-4 dB(A) on older surfaces, but less (2.5-3 dB(A)) on new surfaces.