Experimental demonstrators of vibro-acoustic metamaterials for low frequent NVH insulation

The Noise and Vibration Harshness (NVH) behaviour of products is gaining importance due to increasing customer expectations and more stringent regulations. Ecological trends, however, increase the importance of lightweight design and reduce the applicability of classical (heavy) solutions to improve NVH behaviour. Vibro-acoustic metamaterials come to the fore as candidates for lightweight material systems with superior NVH insulation, be it at least in some targeted and tuneable frequency ranges, referred to as stopbands. These stopbands result from resonant cells arranged on a subwavelength scale.Previously the authors explained the working principles resonant metamaterials, listed the driving parameters for design, and introduced a novel metamaterial concept based on embedding resonant structures. Here the potential is shown for acoustic insulation and broadband vibration reduction in a low frequency zone. This metamaterial concept is eligible for a variety of designs or production processes and can offer technological benefits such as integration in structural parts and use in harsh environments by enclosing the resonant structures, paving the way for a new class of light and compact NVH solutions.