Honeycomb sandwich structures are designed to have a high stiffness-to-mass ratio. The stiff, strong face sheets carry the bending loads, while the core resists shear loads.
The face sheets are typically made from aluminum or carbon fiber with epoxy resin.
The honeycomb core material is usually aluminum for aerospace applications. Other core materials include Nomex aramid or Kevlar para-aramid fiber sheets saturated with a phenolic resin. In addition, closed cell foams such as Rohacell are substituted for honeycomb in some sandwich panel designs.
* * * *
According to Klos, Robinson and Buehrle…
Panels constructed from face sheets laminated to a honeycomb core are being incorporated into the design of modern aircraft fuselage and trim treatments. The mechanical properties of these panels offer a distinct advantage in weight over other commonly used construction materials.
The strength to weight ratio of honeycomb composite panels is high in comparison to rib stiffened aluminum panels used in previous generations of aircraft. However, the high stiffness and low weight can result in supersonic wave propagation at relatively low frequencies, which adversely affects the acoustical performance at these frequencies.
Poor acoustical performance of these types of structures can increase the cabin noise levels to which the passengers and crew are exposed.
* * * *
Here are some references:
Natural Frequencies of a Honeycomb Sandwich Plate: honeyG.pdf
Honeycomb Sandwich Panel Damping: honeycomb_sandwich_damping.pdf
Honeycomb Sandwich Ring Mode Frequency: honeycomb_sandwich_ring_frequency.pdf
Hexcel Honeycomb Sandwich technical information: honeycomb_design.pdf
Sound Transmission through a Curved Honeycomb Composite Panel: ST_curved_honeycomb_panel.pdf
– Tom Irvine