IN-FLIGHT VIBRATION-BASED STRUCTURAL HEALTH MONITORING OF AIRCRAFT WINGS

摘要

This work presents a methodology for automateddamage-sensitive feature extraction and anomalydetection under multivariate operational variabilityfor in-flight assessment of wings. Themethod uses a passive excitation approach, i. e.without the need for artificial actuation. Themodal system properties (natural frequencies anddamping ratios) are used as damage-sensitivefeatures. Special emphasis is placed on the useof Fiber Bragg Grating (FBG) sensing technologyand the consideration of Operational andEnvironmental Variability (OEV). Measurementsfrom a wind tunnel investigation with a compositecantilever equipped with FBG and piezoelectricsensors are used to successfully detect an impactdamage. In addition, the feasibility of damagelocalisation and severity estimation is evaluatedbased on the coupling found between damageandOEV-induced feature changes.