SANDWICH DAMPING TREATMENTS WITH MULTI-LAYER AND MULTI-MATERIAL VISCOELASTIC CORES

Abstract. The application of a viscoelastic core inside a sandwich plate provides an efficient dissipative mechanism able to introduce high levels of damping in light and flexible structures. Due to the decoupling effect produced by the soft viscoelastic core, the flexural stiffness of these sandwich panels can be significantly reduced and, therefore, can compromise the behavior of the damped structure. In this work, it is proposed a multi-layer core configuration which proved to be able to reduce the decoupling effect, maintaining though the treatment efficiency. A multi-material configuration is also proposed providing a good solution to enlarge the efficient temperature range of the damping treatment. A numerical simulation and an experimental study were performed on multi-layer and multi-material specimens. The achieved results verify and sustain the above assumptions and confirm that, under particular temperature conditions, a multi-layer configuration can be more advantageous than using a single layer. The overall flexural stiffness and damping efficiency increase of the sandwich structure are, thus, the most important benefits when adopting a multi-layer configuration.