Reduction of Structure-Borne Tyre/Road Noise through Rubber Resonant Metamaterials in Tyres 2022-01-0954

This paper demonstrates the application of a resonant metamaterial concept to tyres in order to reduce structure-borne tyre/road noise. Special attention is given to the frequency range around 220Hz, containing the first acoustic tyre resonances. These resonances are known to transmit high forces to the wheel-knuckle, leading to structural energy propagating into the vehicle’s body and, consequently, causing a tonal noise issue in the vehicle compartment. By adding recycled rubber resonant elements to the inner liner of the tyre, structural stop band behaviour is achieved in the frequency band of interest. Hence, structural vibrations in the tyre are reduced, resulting in a reduction of the excitation of the first acoustic tyre resonances and, consequently, a mitigation of the transmitted forces to the wheel-knuckle. First, the stop band behaviour is designed via unit cell modelling of a section of a tyre mock-up that only accounts for its structural behaviour. Next, the resonant elements are produced and added to the tyre. Finally, an experimental campaign is carried out to verify the performance of resonant metamaterials in static and rolling conditions.