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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.

In the scope of an SEA project for high frequency tire NVH prediction, use is made of the spatial distribution of “modal power” on the entire surface of a tire, at both the modeling and validation stages. This paper focuses on the model development stage and how the modal power is used to determine the size of the SEA subsystems. Two key results are that, because of large damping, the spatial decay of vibration energy is too great and would require a large number of SEA subsystems. This is a confirmation on the limits of SEA in highly damped systems. It is also found that, in the frequency range where SEA would be useful, the tire's vibration response is concentrated around ⅓ of the tire closer to the excitation location. Experimental results are used to draw more insight into high frequency tire NVH behavior. The paper covers theoretical concepts, measurement setup, data processing, and concludes with useful results.

This paper presents a unified framework for addressing NVH related issues attributed to tire uniformity and Brake rotor DTV. While the focus is on the perceptible manifestation of such vibration (nibble), the presentation goes to the root-cause of nibble and how various suspension/tire/brake components contribute to the generation/amplification of such vibration. While the tire/brake excitation mechanisms have different origins, they cause the same (nibble) symptom to the driver. Results are presented for three types of vehicle suspensions, along with procedures that were developed specifically for this study and some of the understanding that was gained.. Also presented is an efficient data reduction scheme that makes it easy to visualize 3D motions of suspension components and investigate their dynamics.