This paper described a method for modelling certain kinds of damage evolution in distributed mechanical structures using non-linear normal forms. Most structural dynamic systems are of high order; however, they often exhibit phenomena that can be dealt with effectively using low order models. This paper presents a method for describing certain kinds of damage evolution in mechanical systems. The method relies on a simple principle that as damage evolves in a structural dynamic system, the damage indicator (i.e., diagnostic feature) behaves like a stable quasi-stationary equilibrium point in a subsidiary non-linear bifurcating system within the so-called damage center manifold. It is shown that just as linear normal modes govern the behaviour of linear structures with idealised damping, so too do non-linear normal forms govern the evolution of damage within structures in many instances. The method is justified with citations from the literature on certain types of mechanical failure and then applied in an experimental case involving reversible damage in a bolted fastener. Off-line experiments on a rotorcraft fuselage show that the evolution of damage is sensitive to both temporal and spatial bifurcation parameters. A diagnostic sensing strategy whereby output-only transmissibility features are used to decrease the order of high order structural dynamic measurements is also described.
Equilibrium point damage prognosis models for structural health monitoring
Gleichgewichtspunkt-Schadensprognosemodelle zur Struktur-Zustandsüberwachung
2003
21 Seiten, 15 Bilder, 1 Tabelle, 39 Quellen
Aufsatz (Konferenz)
Englisch
Schädigungsmechanismus , Schadenanalyse , Hubschrauber , Zelle (Flugkörper) , Messtechnik , experimentelle Untersuchung , Überlappung , Frequenzbereich , Vorlast , Beschleunigungsmessung , piezoelektrischer Wandler , Signalverarbeitung , Abtastung , Durchlässigkeit , nichtlinearer Effekt , Diagnoseverfahren , Strukturdynamik
Equilibrium point damage prognosis models for structural health monitoring
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