Aircraft parts made of composite materials are susceptible to impact damage which can be negligible visually but significantly worsening their strength. Finding such damage requires periodic monitoring of large areas of the surface of the aircraft airframe. Fundamentally, such monitoring is possible by using active thermography or acoustic methods. Acceptable to practice, this task can be solved by scanning the surface with a rolling dry-point contact transducer array, and by analysis of Lamb wave signals propagating through the monitored material between the array adjacent transducers. This paper presents a device based on this principle, the signal analysis algorithm, and the images recomposed by the device during composite material testing. The developed equipment provides on-line inspection of impact-induced damage in aircraft covering made of composite materials. However, complex type of generated images requires constant monitoring of the covering state of each aircraft during its operation.
CFRP carbon-fiber reinforced plastics, impact induced damages, ultrasonic, transducers with the dry point contact, Lamb waves
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