Resonant Metamaterial Design for Structure-Borne Noise Mitigation. Design Approaches Applied to Automotive Use Cases

In recent years, resonant metamaterials have become an attractive potential alternative to classical noise and vibration control solutions since they can combine lightweight design with high noise and vibration attenuation in targeted frequency ranges, known as stop bands. These stop bands can be achieved by a Fano-type interference due to the addition of resonators on or in a host structure on a subwavelength scale. The design of metamaterials and their stop band performance often relies on infinite periodic structure theory for computational purposes. However, real structures are finite and the finiteness effects arising from boundary conditions, partial treatments and acoustic surroundings, often not included in metamaterial design, can impair the predicted stop band performance. Therefore, this thesis aims to achieve robust metamaterial design and to increase the technology readiness level of these metamaterials as low-frequency structure-borne noise solutions for automotive. The objectives are i) to assess the impact of finiteness effects due to boundary conditions and partial treatment on the stop band performance; ii) to develop design approaches to preserve the beneficial vibro-acoustic behaviour in the stop bands; and based on this know-how, iii) to demonstrate the structure-borne noise mitigation performance in automotive use cases. For the latter, resonant metamaterial concepts are designed for a vehicle shock tower and a tyre and their performance is demonstrated to mitigate the structure-borne noise in the passenger compartment due to the first acoustic tyre resonances.

Jaar van publicatie:2021

Toegankelijkheid:Open