The objective here was to study the control of sound radiation resulting from the structural vibration of a tire excited at one point. First, the tire was modeled as an orthotropic shell by using finite elements and the effect of various tire material parameters on structural wave propagation and the associated sound radiation was estimated. The parameters that were effective at controlling structural wave propagation were then identified. In addition, the radiation field characteristics in the space surrounding a tire placed on a rigid ground were analyzed by using radiation mode analysis. Based on these analyses, a strategy for reducing the radiated sound levels by modifying the tire parameters from a base set was determined. An improved set of material parameters was identified that resulted in reduced sound radiation within a specified target frequency region. That reduction was achieved by an increase of treadband circumferential stiffness that was found to move the onset of longitudinal wave motion within the treadband into a higher frequency region. Secondly, flexural wave propagation was found to be mainly controlled by inflation pressure and cross-sectional treadband stiffness. By appropriate adjustment of these three parameters, it was found possible to substantially reduce sound radiation in a mid-frequency region.
Tire noise, Tire vibration, Wave propagation, Sound radiation, Radiation modes
Acoustics and Noise Control
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