Proper Othrogonal Decomposition of Collocated Signals for Detection of Damage in an Aircraft Propeller

The powerful data-driven analysis furnished by the Proper Orthogonal Decomposition Transform (POD) reveals that ensembles of collocated acceleration signals associated with a sequence of point impulses applied over a backbone curve of a propeller are underlined by a high degree of spatiotemporal coherence, a fact reflecting Maxwell’s reciprocity principle. Thus collocated signals seem to furnish a true spatiotemporal sample of transient response to a point impulse of complex structures such as propellers. In view of this fact, three sensors are placed on an installed propeller to collect collocated signals at the blades and hub for damage detection. Preliminary results indicate that abnormality indicators present in the dominant POD mode of the ensembles of collocated signals are related directly to the presence of damage at the tip of a propeller blade.