Influence of Tire Size and Shape on Sound Radiation from a Tire in the Mid-Frequency Region

In this research, the influence of tire size and shape on sound radiation in the mid-frequency region was studied. First, the relationship between the structural wave propagation characteristics of a tire excited at one point and its sound radiation was identified by using FE and BE analyses. Then, by using that relationship, the effect of modifying a tire's aspect ratio, width and wheel diameter on its sound radiation between 300 Hz and 800 Hz was investigated. Finally, an optimization of the sound radiation was performed by modification of the tire structure and shape. It was found that most of a tire's structural vibration does not contribute to sound radiation. In particular, the effective radiation was found to occur at the frequencies where low wave number components of the longitudinal wave and the flexural wave first appear. In addition, when the tire size and shape were modified, it was found that the flexural wave motion was controlled primarily by the tire cross-sectional length while the longitudinal wave motion was mainly affected by the treadband overall diameter.