Author:

Keywords:

FM_Affiliated, DENORMS, IOF, PDmandaat_Elke, FM_acknowledged, IMALIGHT

Abstract:

Over the past decades, lightweight design solutions are increasingly used for industrial applications, especially in automotive and aerospace, due to economic and environmental requirements. In parallel, performant NVH solutions are required to provide the desired acoustic comfort to customers and to limit the impact of noise exposure on human health. Reduced mass with retained stiffness, however, commonly leads to deteriorated noise and vibration insulation properties. To solve this conflict, locally resonant metamaterials (LRMs) have shown great potential as low mass, compact volume NVH solutions in some tunable frequency zones, referred to as stopbands. LRMs can be obtained by adding resonant elements to a host structure on a subwavelength scale. Due to Fano interference a superior performance in terms of noise and vibration reduction with respect to the conventional NVH treatments can be obtained. In this work, the concept of metamaterials is applied as a vibration mitigation measure in a simplified 2D model representing part of a body of a vehicle excited by a shock absorber. By adding metamaterials on a limited portion of the structure, an average of 6.8 dB with a minimum of 3 dB vibration reduction is achieved in a 50 Hz frequency band centered around 300 Hz, by only adding 2.4 percent of mass to the structure. Numerical and experimental results are shown. The frequency band, the attenuation and the added mass are all tunable by design.