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The Main Rotor Hub is a very critical component of the helicopter considering
that its failure may determine catastrophic consequences for the whole rotorcraft.
A complete experimental and numerical analysis is so necessary to certificate the
fail safe and eventually the damage tolerant behavior of the component. In this
paper the fail safe behavior of a composite titanium-graphite Rotor Hub is
analyzed. The component, with artificial technological defects, was tested with
complex contingent fatigue load in order to cause the failure of the titanium
section. The failure started in proximity of a high stressed area and it propagated
quickly in the whole titanium section but without involve the surrounding
filament winding graphite, that is a fail safe device. The behavior of the hub
during the whole test is simulated, with good accuracy, by means of a complete
FE model that reproduces also the 3D propagation of the crack in the titanium
section.