Abstract: In accordance with the present invention an aircraft floor panel is provided comprising a honeycomb core element having an upper core surface, a lower core surface, and a core thickness. An upper face sheet assembly is mounted to and seals the upper core surface and includes at least one upper material sheet impregnated with an upper epoxy resin. A lower damping face sheet assembly is mounted to and seals the lower core surface and includes at least one lower material sheet infused with a highly damped lower epoxy resin. The lower damping face sheet assembly dampens vibrational noise.

Abstract: Systems and methods for reducing noise in aircraft fuselages and other structures are described herein. A noise reduction system configured in accordance with one embodiment of the invention includes an auxetic core, a damping layer, and a constraining layer. In this embodiment, the auxetic core is supported by a structural member, and the damping layer is sandwiched between the auxetic core and the constraining layer. A method for manufacturing a structural assembly in accordance with another embodiment of the invention includes forming a stiffener by positioning a first ply of composite material against a first tool surface, positioning damping material against the first ply, and positioning a second ply of composite material against the damping material to sandwich the damping material between the first and second plies.