Damage imaging and wavenumber mapping for inspection of bonded CFRP plates using ultrasonic guided waves. 13th European Conference on Non-Destructive Testing
Barzegar, M.
; Lugovtsova, D.
; Bulling, D.
;
Pasadas, D.
;
Ribeiro, A. L.
;
Ramos, H.
Damage imaging and wavenumber mapping for inspection of bonded CFRP plates using ultrasonic guided waves. 13th European Conference on Non-Destructive Testing, Proc European Conference on Non-Destructive Testing ECNDT, Lisbon, Portugal, Vol. , pp. - , July, 2023.
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Abstract
Adhesively bonded CFRP plates are one of the joint structures that receive great
attention from various industries due to the high strength-to-weight ratio. However, these
structures are prone to different defects such as voids, poor cohesive strength, and weak
adhesion strength in the adherend Interface. These defects could be detected using nondestructive
testing by both bulk wave ultrasonic testing and ultrasonic guided Lamb waves.
Damage imaging of the bonded structures requires relevant features to be extracted from
dispersive guided waves propagating in the structure or bulk waves in a C-scan inspection.
Extracting these features is highly dependent on employing advanced signal processing
techniques. Comparing the energy of the received signal in a specific time interval and
wavenumber mapping are two promising methods to achieve an acceptable resolution of the
bonded structure imaging.
This study is presenting damage imaging of the bonded structures using both the wavenumber
mapping method and energy analysis of the trapped waves. The specimen used in this work
is two Carbon-fiber-reinforced polymers (CFRPs) plates bonded by the two-component
Araldite 2011 adhesive. Apart from an intentionally artificial disbond attached to one of the
adherend interfaces using Teflon films, several small voids were produced during the
manufacture. Using a PZT as the excitation of a five-cycle Hann-windowed burst, the guided
waves are recorded by a 3D scanning laser-Doppler vibrometer.
Recorded signals by the laser are processed for image creation of the adhesively bonded
CFRP plate using time-frequency analysis to filter out a single mode sensitive to the loss of
thickness. Filtered data are used for two different types of images including the use of both
wavenumber mapping and trapped energy comparison method and their results are analyzed
with detailed discussion.