@article {Claeys:2015:0736-2935:736, title = "A lightweight vibro-acoustic metamaterial demonstrator: Numerical and experimental investigation.", journal = "INTER-NOISE and NOISE-CON Congress and Conference Proceedings", parent_itemid = "infobike://ince/incecp", publishercode ="ince", year = "2015", volume = "251", number = "1", publication date ="2015-04-13T00:00:00", pages = "736-746", itemtype = "ARTICLE", issn = "0736-2935", url = "https://ince.publisher.ingentaconnect.com/content/ince/incecp/2015/00000251/00000001/art00057", author = "Claeys, Claus and Deckers, Elke and Pluymers, Bert and Desmet, Wim", abstract = "Periodic structures, such as honeycomb core panels, combine excellent mechanical properties with a low mass, making them attractive for application in transport and machine design. However, the high stiffness to mass ratio of these lightweight panels may result in unsatisfactory dynamic behaviour in that it may impair the panels' ability to reduce noise and vibration levels. Liu et al. demonstrated that inclusions of high density spheres with a rubber coating in a matrix material result in low frequency sound insulation breaking the mass law. These locally resonant metamaterials require a high density of local resonators throughout the matrix material, either spread randomly or periodically. In a previous paper by the authors, resonant structures were introduced into the cavities of a honeycomb structure with large cells (30 mm width), leading to a material with strong vibrational attenuation in a low frequency region. This paper discusses the numerical design and experimental validation of acoustic insulation based on the concept of metamaterials: a periodic structure of cells with 10 mm width and added local resonant structures. The stop bands are numerically predicted through unit cell modelling, after which a full vibro-acoustic finite element model is applied to predict the performance of the demonstrator. The results of these analyses are compared with measurements.", }