Honeycomb plates for the Sikorsky helicopter S-92.

 

This paragraph summarizes several works of stress analysis made upon the components of the cabin air-conditioning system of the Sikorsky S-92. The most interesting structures that were analyzed are the supporting plates of the components (heat exchangers, fans, condensers, compressors, pumps, manifolds) and thin shell ducts. The plates are connected to the external structures with a series of rigid supports or flexible anti-vibration mounts and are made of sandwich panels with honeycomb core and multi layered woven carbon fabric prepreg faceplates. They exhibit several holes for the passage of cables and tubes but may be stiffened by the flanges of some components.

The ducts are mixed structures made in a similar manner, in which the honeycomb core is generally missing. The components that load the plate may be often considered as infinitely stiff with respect to the structure itself and can be represented as baricentric masses connected to the mounting points by constraint equations among the master and slave degrees of freedom. The applied loads are principally inertia forces caused by static accelerations, sinusoidal and random vibrations, crash loads. The type of analyses were equivalent static, modal and frequency response with damping.