Guided wavefield curvature imaging of invisible damage in composite structures

Guided wavefields in composite structures carry a wealth of information about wavefield anomalies from damage-wave interactions. Although such anomalies can be used for dam-age detection, they are easily masked by incident waves from actuators and reflected waves from structural boundaries. This research presents a concept of guided wavefield curvature for the detection of structural damage. Wavefield curvature analysis is able to highlight the amplitudes of local anomalies in the wavefield signals associated with damage. A wavefield curvature imaging algorithm is developed for visualizing invisible damage in composite structures. The algorithm is first verified by detecting delamination in a carbon fiber reinforced polymer (CFRP) plate and then applied for detection of debonding in a honeycomb sandwich panel. In the experiments, wavefields are generated by a PZT transducer and are then registered by a scanning laser Doppler vibrometer. The experimental results accord well with the actual locations, sizes, and shapes of the delamination and debonding, confirming the effectiveness of the proposed algorithm for the detection of invisible damage in composite structures. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

Guided wavefield curvature is proposed for the detection of structural damage, highlighting local anomalies associated with damage in wavefield signals. An imaging algorithm is developed for visualizing invisible damage in composite structures, successfully detecting delamination in a CFRP plate and debonding in a honeycomb sandwich panel. The effectiveness of the algorithm is confirmed by experimental results matching the actual locations, sizes, and shapes of the damage.