To understand the NVH mechanism of tire/road noise better than in the past, it is essential to look at the complete sound and vibration field around a tire. Regarding this challenge measurements with a microphone array were performed in the time domain at different speeds, different loads and different inflation pressures.
In this paper first results from the measurements and the calculations for a blank tire are presented. Results from a modal analysis are compared with vibration calculation from sound field measurements around a standing tire excited by a shaker and it is shown how the vibrations are changed when the tire is rolling.
The measured signals were used as input for an Inverse Boundary Element Method (IBEM) calculation of the tire vibration for both non-rolling and rolling. The outer surface of the loaded tire for the IBEM was calculated with in-house FEM software. The IBEM model also incorporates the test rig surface.