Sound Insulation by Laminated Viscoelastic Plates

Abstract

AbstractPlates are basic components in industrial structural design whose acoustical properties are often very important to reduce noise, e.g., in a car or a building. The sound insulation by plates is influenced by various effects, e.g., by the plate's mass but also by their damping capability. Hence, for a realistic analysis, damping should be taken into account which can approximatively be modelled by the use of a viscoelastic material law.Moreover, in automotive industry and structural engineering, laminated plates are very common to improve stiffness and stability, where plates with a viscoelastic core and rigid faces show additionally an excellent acoustical behaviour. Those laminated panes with a viscoelastic core are used in the design of windscreens, and, to improve sound insulation, in the design of building windows.Here, the mechanical behaviour of such a laminated plate is described by using a homogenisation procedure. The damping property of the plate is influenced by the stiffness of the viscoelastic core, it's dissipation factor, and by the thickness of the dissipating layer. These properties of a three‐layer‐plate are mapped on homogenised material parameters of a simple plate via the Ansatz of Ross, Kerwin and Ungar (RKU‐Ansatz).Finally, the sound insulation effectiveness of plates is analysed numerically.