Vibro-Acoustic Metamaterials for Improved Interior NVH Performance in Vehicles

Due to environmental and economic requirements, lightweight design is increasingly used in automotive applications. However, the use of lightweight design typically comes at the cost of impaired NVH performance. Classic solutions to improve the NVH performance usually rely on adding mass or volume, conflicting with lightweight design. In the search for innovative lightweight and compact solutions for noise and vibration reduction, vibro-acoustic locally resonant metamaterials have recently emerged. Through the introduction of local resonances in a flexible host structure on a sub-wavelength scale, frequency ranges without free wave propagation can be created, referred to as stop bands. These stop bands enable achieving targeted frequency ranges of strong noise and vibration attenuation, while the sub-wavelength nature of locally resonant metamaterials enables lighter and thinner vibro-acoustic solutions, which are also able to target the hard-to-address low-frequency range. Since their emergence, the potential of locally resonant metamaterials has been demonstrated and their application to automotive NVH problems has attracted increasing attention. This chapter gives an overview of the vibro-acoustic locally resonant metamaterial research, discusses the potential of these metamaterials for automotive applications and presents a locally resonant metamaterial application for interior noise reduction in a targeted frequency range in a real vehicle.