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Projekt Druckansicht

Berührungslose akustische Defektdetektion und -bildgebung In Faserkunststoffverbunden mittels der Lokalen Defekt Resonanz

Fachliche Zuordnung Messsysteme
Akustik
Kunststofftechnik
Mechanik
Förderung Förderung von 2017 bis 2021
Projektkennung Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 389769996
 
Erstellungsjahr 2022

Zusammenfassung der Projektergebnisse

The project validates LDR concept and applies it to development of new approaches to boost efficiency of ultrasound-activated NDT techniques by having implemented the following: The LDR concept has been extended to a more rigorous analytics for various shapes of planar defects to recognize the impact of these factors on LDR frequency. In nonlinear NDT, the LDR concept has solved a bottleneck problem of low efficiency conversion to nonlinear frequency components. The way to enhance the efficiency of the higher harmonic generation by orders of magnitude has been found by mode matching. A new approach to highly-efficient nonlinear frequency mixing based on LDR is proposed, analysed and tested. In ultrasonic thermography, the progress in LDR studies has enhanced dramatically the efficiency of ultrasonic vibration conversion to heat that removes a long-term obstacle to practical applications of thermosonic NDT. The defect activation of low-energy vibrothermography has been further improved by sweeping the ultrasonic excitation frequency and Fourier-transforming the temperature data. In the framework of the project, a prototype of a mobile and compact testing system potentially applicable in aerospace, train, automotive and wind energy industries has been developed. A manifold (20-30 dB) increase of the damage vibration amplitude provided by LDR opens up wide opportunities for efficient non-contact NDT. A new technique for non-contact NDT provided by commercial sonic equipment uses two-step resonant experimental approach: first, overall acoustic matching between air and the specimen is implemented in the resonant slanted mode, followed by frequency-selective matching via LDR. The other options for non-contact NDT developed are concerned with Resonant Air-Coupled Emission (RACE) detected either by a scanning robotic arm or an immediate full-field defect imaging by using an acoustic camera.

Projektbezogene Publikationen (Auswahl)

 
 

Zusatzinformationen

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